[template] formalized the template definition

- Introduced `Template` & `Template.Parser` interfaces
- There main template implementation is the `ScriptTemplate` and its parser is bound to `Template.Parser`
- There are also xContent templates - YAML & JSON that just render the model as xContent. (used as a fallback in webhook action)
- updated all actions to use the new template infrastructure

Also

- introduced mockito for unit testing
- removed `WebhookTest` as it was effectively testing the template functionality... we'll add a proper test for teh webhook action in a later commit

Original commit: elastic/x-pack-elasticsearch@34a90e8c2f

pom.xml

@@ -86,6 +86,20 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>1.9.5</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency> <!--required for mockito-->
+            <groupId>org.objenesis</groupId>
+            <artifactId>objenesis</artifactId>
+            <version>2.1</version>
+            <scope>test</scope>
+        </dependency>
+
         <!-- Remove this when LocalDiscovery gets fixed in core -->
         <dependency>
             <groupId>com.google.guava</groupId>

src/main/java/org/elasticsearch/alerts/AlertsModule.java

@@ -13,6 +13,7 @@ import org.elasticsearch.alerts.rest.AlertsRestModule;
 import org.elasticsearch.alerts.scheduler.SchedulerModule;
 import org.elasticsearch.alerts.support.TemplateUtils;
 import org.elasticsearch.alerts.support.init.InitializingModule;
+import org.elasticsearch.alerts.support.template.TemplateModule;
 import org.elasticsearch.alerts.transform.TransformModule;
 import org.elasticsearch.alerts.transport.AlertsTransportModule;
 import org.elasticsearch.alerts.condition.ConditionModule;
@@ -28,6 +29,7 @@ public class AlertsModule extends AbstractModule implements SpawnModules {
     public Iterable<? extends Module> spawnModules() {
         return ImmutableList.of(
                 new InitializingModule(),
+                new TemplateModule(),
                 new AlertsClientModule(),
                 new TransformModule(),
                 new AlertsRestModule(),

src/main/java/org/elasticsearch/alerts/actions/Action.java

@@ -8,6 +8,7 @@ package org.elasticsearch.alerts.actions;
 import org.elasticsearch.alerts.ExecutionContext;
 import org.elasticsearch.alerts.Payload;
 import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.collect.ImmutableMap;
 import org.elasticsearch.common.logging.ESLogger;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -19,8 +20,8 @@ import java.io.IOException;
  */
 public abstract class Action<R extends Action.Result> implements ToXContent {
 
-    public static final String ALERT_NAME_VARIABLE_NAME = "alert_name";
+    public static final String ALERT_NAME_VARIABLE = "alert_name";
-    public static final String RESPONSE_VARIABLE_NAME = "response";
+    public static final String PAYLOAD_VARIABLE = "payload";
 
     protected final ESLogger logger;
 
@@ -38,7 +39,12 @@ public abstract class Action<R extends Action.Result> implements ToXContent {
      */
     public abstract R execute(ExecutionContext context, Payload payload) throws IOException;
 
-
+    protected static ImmutableMap<String, Object> templateModel(ExecutionContext ctx, Payload payload) {
+        return ImmutableMap.<String, Object>builder()
+                .put(ALERT_NAME_VARIABLE, ctx.alert().name())
+                .put(PAYLOAD_VARIABLE, payload.data())
+                .build();
+    }
     /**
      * Parses xcontent to a concrete action of the same type.
      */
@@ -57,8 +63,6 @@ public abstract class Action<R extends Action.Result> implements ToXContent {
         R parseResult(XContentParser parser) throws IOException;
     }
 
-
-
     public static abstract class Result implements ToXContent {
 
         public static final ParseField SUCCESS_FIELD = new ParseField("success");

src/main/java/org/elasticsearch/alerts/actions/ActionSettingsException.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.alerts.actions;
+
+/**
+ *
+ */
+public class ActionSettingsException extends ActionException {
+
+    public ActionSettingsException(String msg) {
+        super(msg);
+    }
+
+    public ActionSettingsException(String msg, Throwable cause) {
+        super(msg, cause);
+    }
+}

src/main/java/org/elasticsearch/alerts/actions/email/EmailAction.java

@@ -8,9 +8,11 @@ package org.elasticsearch.alerts.actions.email;
 import org.elasticsearch.alerts.ExecutionContext;
 import org.elasticsearch.alerts.Payload;
 import org.elasticsearch.alerts.actions.Action;
+import org.elasticsearch.alerts.actions.ActionSettingsException;
 import org.elasticsearch.alerts.actions.email.service.*;
-import org.elasticsearch.alerts.support.StringTemplateUtils;
+import org.elasticsearch.alerts.support.template.Template;
 import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.collect.ImmutableMap;
 import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.logging.ESLogger;
@@ -20,8 +22,6 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 
 import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
 
 /**
  */
@@ -33,21 +33,18 @@ public class EmailAction extends Action<EmailAction.Result> {
     private final Authentication auth;
     private final Profile profile;
     private final String account;
-    private final StringTemplateUtils.Template subject;
+    private final Template subject;
-    private final StringTemplateUtils.Template textBody;
+    private final Template textBody;
-    private final StringTemplateUtils.Template htmlBody;
+    private final Template htmlBody;
     private final boolean attachPayload;
 
     private final EmailService emailService;
-    private final StringTemplateUtils templateUtils;
 
-    public EmailAction(ESLogger logger, EmailService emailService, StringTemplateUtils templateUtils,
+    public EmailAction(ESLogger logger, EmailService emailService, Email.Builder email, Authentication auth, Profile profile,
-                          Email.Builder email, Authentication auth, Profile profile, String account,
+                       String account, Template subject, Template textBody, Template htmlBody, boolean attachPayload) {
-                          StringTemplateUtils.Template subject, StringTemplateUtils.Template textBody,
+
-                          StringTemplateUtils.Template htmlBody, boolean attachPayload) {
         super(logger);
         this.emailService = emailService;
-        this.templateUtils = templateUtils;
         this.email = email;
         this.auth = auth;
         this.profile = profile;
@@ -65,21 +62,14 @@ public class EmailAction extends Action<EmailAction.Result> {
 
     @Override
     public Result execute(ExecutionContext ctx, Payload payload) throws IOException {
+        ImmutableMap<String, Object> model = templateModel(ctx, payload);
+
         email.id(ctx.id());
-
+        email.subject(subject.render(model));
-        Map<String, Object> alertParams = new HashMap<>();
+        email.textBody(textBody.render(model));
-        alertParams.put(Action.ALERT_NAME_VARIABLE_NAME, ctx.alert().name());
-        alertParams.put(RESPONSE_VARIABLE_NAME, payload.data());
-
-        String text = templateUtils.executeTemplate(subject, alertParams);
-        email.subject(text);
-
-        text = templateUtils.executeTemplate(textBody, alertParams);
-        email.textBody(text);
 
         if (htmlBody != null) {
-            text = templateUtils.executeTemplate(htmlBody, alertParams);
+            email.htmlBody(htmlBody.render(model));
-            email.htmlBody(text);
         }
 
         if (attachPayload) {
@@ -100,17 +90,17 @@ public class EmailAction extends Action<EmailAction.Result> {
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject();
         if (account != null) {
-            builder.field(Parser.ACCOUNT_FIELD.getPreferredName(), account);
+            builder.field(EmailAction.Parser.ACCOUNT_FIELD.getPreferredName(), account);
         }
         if (profile != null) {
-            builder.field(Parser.PROFILE_FIELD.getPreferredName(), profile);
+            builder.field(EmailAction.Parser.PROFILE_FIELD.getPreferredName(), profile);
         }
         builder.field(Email.TO_FIELD.getPreferredName(), (ToXContent) email.to());
         if (subject != null) {
-            StringTemplateUtils.writeTemplate(Email.SUBJECT_FIELD.getPreferredName(), subject, builder, params);
+            builder.field(Email.SUBJECT_FIELD.getPreferredName(), subject);
         }
         if (textBody != null) {
-            StringTemplateUtils.writeTemplate(Email.TEXT_BODY_FIELD.getPreferredName(), textBody, builder, params);
+            builder.field(Email.TEXT_BODY_FIELD.getPreferredName(), textBody);
         }
         return builder.endObject();
     }
@@ -125,14 +115,14 @@ public class EmailAction extends Action<EmailAction.Result> {
         public static final ParseField EMAIL_FIELD = new ParseField("email");
         public static final ParseField REASON_FIELD = new ParseField("reason");
 
-        private final StringTemplateUtils templateUtils;
+        private final Template.Parser templateParser;
         private final EmailService emailService;
 
         @Inject
-        public Parser(Settings settings, EmailService emailService, StringTemplateUtils templateUtils) {
+        public Parser(Settings settings, EmailService emailService, Template.Parser templateParser) {
             super(settings);
             this.emailService = emailService;
-            this.templateUtils = templateUtils;
+            this.templateParser = templateParser;
         }
 
         @Override
@@ -147,9 +137,9 @@ public class EmailAction extends Action<EmailAction.Result> {
             String account = null;
             Profile profile = null;
             Email.Builder email = Email.builder();
-            StringTemplateUtils.Template subject = null;
+            Template subject = null;
-            StringTemplateUtils.Template textBody = null;
+            Template textBody = null;
-            StringTemplateUtils.Template htmlBody = null;
+            Template htmlBody = null;
             boolean attachPayload = false;
 
             String currentFieldName = null;
@@ -169,15 +159,27 @@ public class EmailAction extends Action<EmailAction.Result> {
                     } else if (Email.BCC_FIELD.match(currentFieldName)) {
                         email.bcc(Email.AddressList.parse(currentFieldName, token, parser));
                     } else if (Email.SUBJECT_FIELD.match(currentFieldName)) {
-                        subject = StringTemplateUtils.readTemplate(parser);
+                        try {
+                            subject = templateParser.parse(parser);
+                        } catch (Template.Parser.ParseException pe) {
+                            throw new ActionSettingsException("could not parse email [subject] template", pe);
+                        }
                     } else if (Email.TEXT_BODY_FIELD.match(currentFieldName)) {
-                        textBody = StringTemplateUtils.readTemplate(parser);
+                        try {
+                            textBody = templateParser.parse(parser);
+                        } catch (Template.Parser.ParseException pe) {
+                            throw new ActionSettingsException("could not parse email [text_body] template", pe);
+                        }
+                    } else if (Email.HTML_BODY_FIELD.match(currentFieldName)) {
+                        try {
+                            htmlBody = templateParser.parse(parser);
+                        } catch (Template.Parser.ParseException pe) {
+                            throw new ActionSettingsException("could not parse email [html_body] template", pe);
+                        }
                     } else if (token == XContentParser.Token.VALUE_STRING) {
                         if (Email.PRIORITY_FIELD.match(currentFieldName)) {
                             email.priority(Email.Priority.resolve(parser.text()));
-                        }  else if (Email.HTML_BODY_FIELD.match(currentFieldName)) {
+                        }  else if (ACCOUNT_FIELD.match(currentFieldName)) {
-                            htmlBody = StringTemplateUtils.readTemplate(parser);
-                        } else if (ACCOUNT_FIELD.match(currentFieldName)) {
                             account = parser.text();
                         } else if (USER_FIELD.match(currentFieldName)) {
                             user = parser.text();
@@ -186,26 +188,26 @@ public class EmailAction extends Action<EmailAction.Result> {
                         } else if (PROFILE_FIELD.match(currentFieldName)) {
                             profile = Profile.resolve(parser.text());
                         } else {
-                            throw new EmailException("could not parse email action. unrecognized string field [" + currentFieldName + "]");
+                            throw new ActionSettingsException("could not parse email action. unrecognized string field [" + currentFieldName + "]");
                         }
                     } else if (token == XContentParser.Token.VALUE_BOOLEAN) {
                         if (ATTACH_PAYLOAD_FIELD.match(currentFieldName)) {
                             attachPayload = parser.booleanValue();
                         } else {
-                            throw new EmailException("could not parse email action. unrecognized boolean field [" + currentFieldName + "]");
+                            throw new ActionSettingsException("could not parse email action. unrecognized boolean field [" + currentFieldName + "]");
                         }
                     } else {
-                        throw new EmailException("could not parse email action. unexpected token [" + token + "]");
+                        throw new ActionSettingsException("could not parse email action. unexpected token [" + token + "]");
                     }
                 }
             }
 
             if (email.to() == null || email.to().isEmpty()) {
-                throw new EmailException("could not parse email action. [to] was not found or was empty");
+                throw new ActionSettingsException("could not parse email action. [to] was not found or was empty");
             }
 
             Authentication auth = new Authentication(user, password);
-            return new EmailAction(logger, emailService, templateUtils, email, auth, profile, account, subject, textBody, htmlBody, attachPayload);
+            return new EmailAction(logger, emailService, email, auth, profile, account, subject, textBody, htmlBody, attachPayload);
         }
 
         @Override

src/main/java/org/elasticsearch/alerts/actions/index/IndexAction.java

@@ -12,6 +12,7 @@ import org.elasticsearch.alerts.ExecutionContext;
 import org.elasticsearch.alerts.Payload;
 import org.elasticsearch.alerts.actions.Action;
 import org.elasticsearch.alerts.actions.ActionException;
+import org.elasticsearch.alerts.actions.ActionSettingsException;
 import org.elasticsearch.alerts.support.init.proxy.ClientProxy;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.component.AbstractComponent;
@@ -90,6 +91,26 @@ public class IndexAction extends Action<IndexAction.Result> {
         return builder;
     }
 
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        IndexAction that = (IndexAction) o;
+
+        if (index != null ? !index.equals(that.index) : that.index != null) return false;
+        if (type != null ? !type.equals(that.type) : that.type != null) return false;
+
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = index != null ? index.hashCode() : 0;
+        result = 31 * result + (type != null ? type.hashCode() : 0);
+        return result;
+    }
+
     public static class Parser extends AbstractComponent implements Action.Parser<Result, IndexAction> {
 
         public static final ParseField INDEX_FIELD = new ParseField("index");
@@ -127,19 +148,19 @@ public class IndexAction extends Action<IndexAction.Result> {
                     } else if (TYPE_FIELD.match(currentFieldName)) {
                         type = parser.text();
                     } else {
-                        throw new ActionException("could not parse index action. unexpected field [" + currentFieldName + "]");
+                        throw new ActionSettingsException("could not parse index action. unexpected field [" + currentFieldName + "]");
                     }
                 } else {
-                    throw new ActionException("could not parse index action. unexpected token [" + token + "]");
+                    throw new ActionSettingsException("could not parse index action. unexpected token [" + token + "]");
                 }
             }
 
             if (index == null) {
-                throw new ActionException("could not parse index action [index] is required");
+                throw new ActionSettingsException("could not parse index action [index] is required");
             }
 
             if (type == null) {
-                throw new ActionException("could not parse index action [type] is required");
+                throw new ActionSettingsException("could not parse index action [type] is required");
             }
 
             return new IndexAction(logger, client, index, type);
@@ -215,24 +236,4 @@ public class IndexAction extends Action<IndexAction.Result> {
 
     }
 
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        IndexAction that = (IndexAction) o;
-
-        if (index != null ? !index.equals(that.index) : that.index != null) return false;
-        if (type != null ? !type.equals(that.type) : that.type != null) return false;
-
-        return true;
-    }
-
-    @Override
-    public int hashCode() {
-        int result = index != null ? index.hashCode() : 0;
-        result = 31 * result + (type != null ? type.hashCode() : 0);
-        return result;
-    }
 }

src/main/java/org/elasticsearch/alerts/actions/webhook/WebhookAction.java

@@ -5,13 +5,17 @@
  */
 package org.elasticsearch.alerts.actions.webhook;
 
+import org.elasticsearch.alerts.AlertsSettingsException;
 import org.elasticsearch.alerts.ExecutionContext;
 import org.elasticsearch.alerts.Payload;
 import org.elasticsearch.alerts.actions.Action;
 import org.elasticsearch.alerts.actions.ActionException;
-import org.elasticsearch.alerts.support.StringTemplateUtils;
+import org.elasticsearch.alerts.actions.ActionSettingsException;
+import org.elasticsearch.alerts.support.template.Template;
+import org.elasticsearch.alerts.support.template.XContentTemplate;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.collect.ImmutableMap;
 import org.elasticsearch.common.component.AbstractComponent;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.logging.ESLogger;
@@ -21,8 +25,6 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 
 import java.io.IOException;
-import java.util.HashMap;
-import java.util.Map;
 
 /**
  */
@@ -30,27 +32,18 @@ public class WebhookAction extends Action<WebhookAction.Result> {
 
     public static final String TYPE = "webhook";
 
-    static final StringTemplateUtils.Template DEFAULT_BODY_TEMPLATE = new StringTemplateUtils.Template(
-            "{ 'alertname' : '{{alert_name}}', 'response' : {{response}} }");
-
-    private final StringTemplateUtils templateUtils;
     private final HttpClient httpClient;
 
-    private final StringTemplateUtils.Template urlTemplate;
     private final HttpMethod method;
+    private final Template url;
+    private final @Nullable Template body;
 
-    //Optional, default will be used if not provided
+    public WebhookAction(ESLogger logger, HttpClient httpClient, HttpMethod method, Template url, Template body) {
-    private final StringTemplateUtils.Template bodyTemplate;
-
-    public WebhookAction(ESLogger logger, StringTemplateUtils templateUtils, HttpClient httpClient,
-                            @Nullable StringTemplateUtils.Template bodyTemplate,
-                            StringTemplateUtils.Template urlTemplate, HttpMethod method) {
         super(logger);
-        this.templateUtils = templateUtils;
         this.httpClient = httpClient;
-        this.bodyTemplate = bodyTemplate;
-        this.urlTemplate = urlTemplate;
         this.method = method;
+        this.url = url;
+        this.body = body;
     }
 
     @Override
@@ -60,44 +53,62 @@ public class WebhookAction extends Action<WebhookAction.Result> {
 
     @Override
     public Result execute(ExecutionContext ctx, Payload payload) throws IOException {
-        Map<String, Object> data = payload.data();
+        ImmutableMap<String, Object> model = ImmutableMap.<String, Object>builder()
-        String renderedUrl = applyTemplate(templateUtils, urlTemplate, ctx.alert().name(), data);
+                .put(ALERT_NAME_VARIABLE, ctx.alert().name())
-        String body = applyTemplate(templateUtils, bodyTemplate != null ? bodyTemplate : DEFAULT_BODY_TEMPLATE, ctx.alert().name(), data);
+                .put(PAYLOAD_VARIABLE, payload.data())
+                .build();
+        String urlText = url.render(model);
+        String bodyText = body != null ? body.render(model) : XContentTemplate.YAML.render(model);
         try {
 
-            int status = httpClient.execute(method, renderedUrl, body);
+            int status = httpClient.execute(method, urlText, bodyText);
             if (status >= 400) {
-                logger.warn("got status [" + status + "] when connecting to [" + renderedUrl + "]");
+                logger.warn("got status [" + status + "] when connecting to [" + urlText + "]");
             } else {
                 if (status >= 300) {
                     logger.warn("a 200 range return code was expected, but got [" + status + "]");
                 }
             }
-            return new Result.Executed(status, renderedUrl, body);
+            return new Result.Executed(status, urlText, bodyText);
+
         } catch (IOException ioe) {
-            logger.error("failed to connect to [{}] for alert [{}]", ioe, renderedUrl, ctx.alert().name());
+            logger.error("failed to connect to [{}] for alert [{}]", ioe, urlText, ctx.alert().name());
             return new Result.Failure("failed to send http request. " + ioe.getMessage());
         }
 
     }
 
-    static String applyTemplate(StringTemplateUtils templateUtils, StringTemplateUtils.Template template, String alertName, Map<String, Object> data) {
-        Map<String, Object> webHookParams = new HashMap<>();
-        webHookParams.put(ALERT_NAME_VARIABLE_NAME, alertName);
-        webHookParams.put(RESPONSE_VARIABLE_NAME, data);
-        return templateUtils.executeTemplate(template, webHookParams);
-    }
-
     @Override
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject();
         builder.field(Parser.METHOD_FIELD.getPreferredName(), method.getName());
-        if (bodyTemplate != null) {
+        builder.field(Parser.URL_FIELD.getPreferredName(), url);
-            StringTemplateUtils.writeTemplate(Parser.BODY_TEMPLATE_FIELD.getPreferredName(), bodyTemplate, builder, params);
+        if (body != null) {
+            builder.field(Parser.BODY_FIELD.getPreferredName(), body);
         }
-        StringTemplateUtils.writeTemplate(Parser.URL_TEMPLATE_FIELD.getPreferredName(), urlTemplate, builder, params);
+        return builder.endObject();
-        builder.endObject();
+    }
-        return builder;
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        WebhookAction that = (WebhookAction) o;
+
+        if (!body.equals(that.body)) return false;
+        if (!method.equals(that.method)) return false;
+        if (!url.equals(that.url)) return false;
+
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = method.hashCode();
+        result = 31 * result + url.hashCode();
+        result = 31 * result + body.hashCode();
+        return result;
     }
 
     public abstract static class Result extends Action.Result {
@@ -108,19 +119,19 @@ public class WebhookAction extends Action<WebhookAction.Result> {
 
         public static class Executed extends Result {
 
-            private final int httpStatusCode;
+            private final int httpStatus;
             private final String url;
             private final String body;
 
-            public Executed(int httpStatusCode, String url, String body) {
+            public Executed(int httpStatus, String url, String body) {
-                super(TYPE, httpStatusCode < 400);
+                super(TYPE, httpStatus < 400);
-                this.httpStatusCode = httpStatusCode;
+                this.httpStatus = httpStatus;
                 this.url = url;
                 this.body = body;
             }
 
-            public int httpStatusCode() {
+            public int httpStatus() {
-                return httpStatusCode;
+                return httpStatus;
             }
 
             public String url() {
@@ -134,9 +145,9 @@ public class WebhookAction extends Action<WebhookAction.Result> {
             @Override
             protected XContentBuilder xContentBody(XContentBuilder builder, Params params) throws IOException {
                 return builder.field("success", success())
-                        .field(Parser.HTTP_STATUS_FIELD.getPreferredName(), httpStatusCode)
+                        .field(WebhookAction.Parser.HTTP_STATUS_FIELD.getPreferredName(), httpStatus)
-                        .field(Parser.URL_FIELD.getPreferredName(), url)
+                        .field(WebhookAction.Parser.URL_FIELD.getPreferredName(), url)
-                        .field(Parser.BODY_FIELD.getPreferredName(), body);
+                        .field(WebhookAction.Parser.BODY_FIELD.getPreferredName(), body);
             }
         }
 
@@ -151,7 +162,7 @@ public class WebhookAction extends Action<WebhookAction.Result> {
 
             @Override
             protected XContentBuilder xContentBody(XContentBuilder builder, Params params) throws IOException {
-                return builder.field(Parser.REASON_FIELD.getPreferredName(), reason);
+                return builder.field(WebhookAction.Parser.REASON_FIELD.getPreferredName(), reason);
             }
         }
     }
@@ -160,21 +171,18 @@ public class WebhookAction extends Action<WebhookAction.Result> {
     public static class Parser extends AbstractComponent implements Action.Parser<Result, WebhookAction> {
 
         public static final ParseField METHOD_FIELD = new ParseField("method");
-        public static final ParseField URL_TEMPLATE_FIELD = new ParseField("url_template");
-        public static final ParseField BODY_TEMPLATE_FIELD = new ParseField("body_template");
-
-        public static final ParseField BODY_FIELD = new ParseField("body");
         public static final ParseField URL_FIELD = new ParseField("url");
+        public static final ParseField BODY_FIELD = new ParseField("body");
         public static final ParseField HTTP_STATUS_FIELD = new ParseField("http_status");
         public static final ParseField REASON_FIELD = new ParseField("reason");
 
-        private final StringTemplateUtils templateUtils;
+        private final Template.Parser templateParser;
         private final HttpClient httpClient;
 
         @Inject
-        public Parser(Settings settings, StringTemplateUtils templateUtils, HttpClient httpClient) {
+        public Parser(Settings settings, Template.Parser templateParser, HttpClient httpClient) {
             super(settings);
-            this.templateUtils = templateUtils;
+            this.templateParser = templateParser;
             this.httpClient = httpClient;
         }
 
@@ -186,8 +194,8 @@ public class WebhookAction extends Action<WebhookAction.Result> {
         @Override
         public WebhookAction parse(XContentParser parser) throws IOException {
             HttpMethod method = HttpMethod.POST;
-            StringTemplateUtils.Template urlTemplate = null;
+            Template urlTemplate = null;
-            StringTemplateUtils.Template bodyTemplate = null;
+            Template bodyTemplate = null;
 
             String currentFieldName = null;
             XContentParser.Token token;
@@ -199,26 +207,33 @@ public class WebhookAction extends Action<WebhookAction.Result> {
                     if (METHOD_FIELD.match(currentFieldName)) {
                         method = HttpMethod.valueOf(parser.text());
                         if (method != HttpMethod.POST && method != HttpMethod.GET && method != HttpMethod.PUT) {
-                            throw new ActionException("could not parse webhook action. unsupported http method ["
+                            throw new ActionSettingsException("could not parse webhook action. unsupported http method [" + method.getName() + "]");
-                                    + method.getName() + "]");
+                        }
+                    } else if (URL_FIELD.match(currentFieldName)) {
+                        try {
+                            urlTemplate = templateParser.parse(parser);
+                        } catch (Template.Parser.ParseException pe) {
+                            throw new AlertsSettingsException("could not parse webhook action [url] template", pe);
+                        }
+                    } else if (BODY_FIELD.match(currentFieldName)) {
+                        try {
+                            bodyTemplate = templateParser.parse(parser);
+                        } catch (Template.Parser.ParseException pe) {
+                            throw new ActionSettingsException("could not parse webhook action [body] template", pe);
                         }
-                    } else if (URL_TEMPLATE_FIELD.match(currentFieldName)) {
-                        urlTemplate = StringTemplateUtils.readTemplate(parser);
-                    } else if (BODY_TEMPLATE_FIELD.match(currentFieldName)) {
-                        bodyTemplate = StringTemplateUtils.readTemplate(parser);
                     }  else {
-                        throw new ActionException("could not parse webhook action. unexpected field [" + currentFieldName + "]");
+                        throw new ActionSettingsException("could not parse webhook action. unexpected field [" + currentFieldName + "]");
                     }
                 } else {
-                    throw new ActionException("could not parse webhook action. unexpected token [" + token + "]");
+                    throw new ActionSettingsException("could not parse webhook action. unexpected token [" + token + "]");
                 }
             }
 
             if (urlTemplate == null) {
-                throw new ActionException("could not parse webhook action. [url_template] is required");
+                throw new ActionSettingsException("could not parse webhook action. [url_template] is required");
             }
 
-            return new WebhookAction(logger, templateUtils, httpClient, bodyTemplate, urlTemplate, method);
+            return new WebhookAction(logger, httpClient, method, urlTemplate, bodyTemplate);
         }
 
         @Override
@@ -264,25 +279,4 @@ public class WebhookAction extends Action<WebhookAction.Result> {
         }
     }
 
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        WebhookAction that = (WebhookAction) o;
-
-        if (bodyTemplate != null ? !bodyTemplate.equals(that.bodyTemplate) : that.bodyTemplate != null) return false;
-        if (method != null ? !method.equals(that.method) : that.method != null) return false;
-        if (urlTemplate != null ? !urlTemplate.equals(that.urlTemplate) : that.urlTemplate != null) return false;
-
-        return true;
-    }
-
-    @Override
-    public int hashCode() {
-        int result = urlTemplate != null ? urlTemplate.hashCode() : 0;
-        result = 31 * result + (method != null ? method.hashCode() : 0);
-        result = 31 * result + (bodyTemplate != null ? bodyTemplate.hashCode() : 0);
-        return result;
-    }
 }

src/main/java/org/elasticsearch/alerts/support/AlertUtils.java

@@ -134,7 +134,7 @@ public final class AlertUtils {
                         searchRequest.templateName(parser.textOrNull());
                         break;
                     case "template_type":
-                        searchRequest.templateType(readScriptType(parser.textOrNull()));
+                        searchRequest.templateType(ScriptService.ScriptType.valueOf(parser.text().toUpperCase(Locale.ROOT)));
                         break;
                     case "search_type":
                         searchType = SearchType.fromString(parser.text());
@@ -169,7 +169,7 @@ public final class AlertUtils {
             builder.field("template_name", searchRequest.templateName());
         }
         if (searchRequest.templateType() != null) {
-            builder.field("template_type", writeScriptType(searchRequest.templateType()));
+            builder.field("template_type", searchRequest.templateType().name().toLowerCase(Locale.ROOT));
         }
         builder.startArray("indices");
         for (String index : searchRequest.indices()) {
@@ -200,30 +200,4 @@ public final class AlertUtils {
         builder.endObject();
     }
 
-    static ScriptService.ScriptType readScriptType(String value) {
-        switch (value) {
-            case "indexed":
-                return ScriptService.ScriptType.INDEXED;
-            case "inline":
-                return ScriptService.ScriptType.INLINE;
-            case "file":
-                return ScriptService.ScriptType.FILE;
-            default:
-                throw new ElasticsearchIllegalArgumentException("Unknown script_type value [" + value + "]");
-        }
-    }
-
-    static String writeScriptType(ScriptService.ScriptType value) {
-        switch (value) {
-            case INDEXED:
-                return "indexed";
-            case INLINE:
-                return "inline";
-            case FILE:
-                return "file";
-            default:
-                throw new ElasticsearchIllegalArgumentException("Illegal script_type value [" + value + "]");
-        }
-    }
-
 }

src/main/java/org/elasticsearch/alerts/support/StringTemplateUtils.java

@@ -1,166 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License;
- * you may not use this file except in compliance with the Elastic License.
- */
-package org.elasticsearch.alerts.support;
-
-
-import org.elasticsearch.ElasticsearchIllegalArgumentException;
-import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
-import org.elasticsearch.common.bytes.BytesReference;
-import org.elasticsearch.common.component.AbstractComponent;
-import org.elasticsearch.common.inject.Inject;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.xcontent.ToXContent;
-import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.script.ExecutableScript;
-import org.elasticsearch.script.ScriptService;
-
-import java.io.IOException;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-
-/**
- */
-public class StringTemplateUtils extends AbstractComponent {
-
-    private final ScriptServiceProxy scriptService;
-
-    @Inject
-    public StringTemplateUtils(Settings settings, ScriptServiceProxy scriptService) {
-        super(settings);
-        this.scriptService = scriptService;
-    }
-
-    public String executeTemplate(Template template) {
-        return executeTemplate(template, Collections.<String, Object>emptyMap());
-    }
-
-    public String executeTemplate(Template template, Map<String, Object> additionalParams) {
-        Map<String, Object> params = new HashMap<>();
-        params.putAll(template.getParams());
-        params.putAll(additionalParams);
-        ExecutableScript script = scriptService.executable(template.getLanguage(), template.getTemplate(), template.getScriptType(), params);
-        Object result = script.run();
-        if (result instanceof String) {
-            return (String) result;
-        } else if (result instanceof BytesReference) {
-            return ((BytesReference) script.run()).toUtf8();
-        } else {
-            return result.toString();
-        }
-    }
-    public static Template readTemplate(XContentParser parser) throws IOException {
-        assert parser.currentToken() == XContentParser.Token.START_OBJECT : "Expected START_OBJECT, but was " + parser.currentToken();
-        Map<String, String> params = null;
-        String script = null;
-        ScriptService.ScriptType type = ScriptService.ScriptType.INLINE;
-        String language = "mustache";
-        String fieldName = parser.currentName();
-        for (XContentParser.Token token = parser.nextToken(); token != XContentParser.Token.END_OBJECT; token = parser.nextToken()) {
-            switch (token) {
-                case FIELD_NAME:
-                    fieldName = parser.currentName();
-                    break;
-                case START_OBJECT:
-                    switch (fieldName) {
-                        case "params":
-                            params = (Map) parser.map();
-                            break;
-                        default:
-                            throw new ElasticsearchIllegalArgumentException("Unexpected field [" + fieldName + "]");
-                    }
-                    break;
-                case VALUE_STRING:
-                    switch (fieldName) {
-                        case "script":
-                            script = parser.text();
-                            break;
-                        case "language":
-                            language = parser.text();
-                            break;
-                        case "type":
-                            type = AlertUtils.readScriptType(parser.text());
-                            break;
-                        default:
-                            throw new ElasticsearchIllegalArgumentException("Unexpected field [" + fieldName + "]");
-                    }
-                    break;
-                default:
-                    throw new ElasticsearchIllegalArgumentException("Unexpected json token [" + token + "]");
-            }
-        }
-        return new Template(script, params, language, type);
-    }
-
-    public static void writeTemplate(String objectName, Template template, XContentBuilder builder, ToXContent.Params params) throws IOException {
-        builder.startObject(objectName);
-        builder.field("script", template.getTemplate());
-        builder.field("type", AlertUtils.writeScriptType(template.getScriptType()));
-        builder.field("language", template.getLanguage());
-        if (template.getParams() != null && !template.getParams().isEmpty()) {
-            builder.field("params", template.getParams());
-        }
-        builder.endObject();
-    }
-
-    public static class Template {
-        private final String template;
-        private final Map<String, String> params;
-        private final String language;
-        private final ScriptService.ScriptType scriptType;
-        public Template(String template) {
-            this.template = template;
-            this.params = Collections.emptyMap();
-            this.language = "mustache";
-            this.scriptType = ScriptService.ScriptType.INLINE;
-        }
-        public Template(String template, Map<String, String> params, String language, ScriptService.ScriptType scriptType) {
-            this.template = template;
-            this.params = params;
-            this.language = language;
-            this.scriptType = scriptType;
-        }
-        public ScriptService.ScriptType getScriptType() {
-            return scriptType;
-        }
-        public String getTemplate() {
-            return template;
-        }
-        public String getLanguage() {
-            return language;
-        }
-        public Map<String, String> getParams() {
-            return params;
-        }
-
-
-        @Override
-        public boolean equals(Object o) {
-            if (this == o) return true;
-            if (o == null || getClass() != o.getClass()) return false;
-
-            Template template1 = (Template) o;
-
-            if (language != null ? !language.equals(template1.language) : template1.language != null) return false;
-            if (params != null ? !params.equals(template1.params) : template1.params != null) return false;
-            if (scriptType != template1.scriptType) return false;
-            if (template != null ? !template.equals(template1.template) : template1.template != null) return false;
-
-            return true;
-        }
-
-        @Override
-        public int hashCode() {
-            int result = template != null ? template.hashCode() : 0;
-            result = 31 * result + (params != null ? params.hashCode() : 0);
-            result = 31 * result + (language != null ? language.hashCode() : 0);
-            result = 31 * result + (scriptType != null ? scriptType.hashCode() : 0);
-            return result;
-        }
-    }
-}
-

src/main/java/org/elasticsearch/alerts/support/template/ScriptTemplate.java

@@ -0,0 +1,193 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.alerts.support.template;
+
+import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.base.Function;
+import org.elasticsearch.common.base.Joiner;
+import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.collect.Collections2;
+import org.elasticsearch.common.collect.ImmutableList;
+import org.elasticsearch.common.collect.ImmutableMap;
+import org.elasticsearch.common.component.AbstractComponent;
+import org.elasticsearch.common.inject.Inject;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.script.ExecutableScript;
+import org.elasticsearch.script.ScriptService;
+
+import java.io.IOException;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
+
+/**
+ *
+ */
+public class ScriptTemplate implements ToXContent, Template {
+
+    static final ParseField TEXT_FIELD = new ParseField("script", "text");
+    static final ParseField LANG_FIELD = new ParseField("lang", "language", "script_lang");
+    static final ParseField TYPE_FIELD = new ParseField("type", "script_type");
+    static final ParseField PARAMS_FIELD = new ParseField("model", "params");
+
+    public static final String DEFAULT_LANG = "mustache";
+
+    private final String text;
+    private final String lang;
+    private final ScriptService.ScriptType type;
+    private final Map<String, Object> params;
+    private final ScriptServiceProxy service;
+
+    public ScriptTemplate(ScriptServiceProxy service, String text) {
+        this(service, text, DEFAULT_LANG, ScriptService.ScriptType.INLINE, Collections.<String, Object>emptyMap());
+    }
+
+    public ScriptTemplate(ScriptServiceProxy service, String text, String lang, ScriptService.ScriptType type, Map<String, Object> params) {
+        this.service = service;
+        this.text = text;
+        this.lang = lang;
+        this.type = type;
+        this.params = params;
+    }
+
+    public String text() {
+        return text;
+    }
+
+    public ScriptService.ScriptType type() {
+        return type;
+    }
+
+    public String lang() {
+        return lang;
+    }
+
+    public Map<String, Object> params() {
+        return params;
+    }
+
+    @Override
+    public String render(Map<String, Object> model) {
+        Map<String, Object> mergedModel = new HashMap<>();
+        mergedModel.putAll(params);
+        mergedModel.putAll(model);
+        ExecutableScript script = service.executable(lang, text, type, mergedModel);
+        Object result = script.run();
+        if (result instanceof BytesReference) {
+            return ((BytesReference) script.run()).toUtf8();
+        }
+        return result.toString();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        ScriptTemplate template = (ScriptTemplate) o;
+
+        if (!lang.equals(template.lang)) return false;
+        if (!params.equals(template.params)) return false;
+        if (!text.equals(template.text)) return false;
+        if (type != template.type) return false;
+
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = text.hashCode();
+        result = 31 * result + lang.hashCode();
+        result = 31 * result + type.hashCode();
+        result = 31 * result + params.hashCode();
+        return result;
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        return builder.startObject()
+                .field(TEXT_FIELD.getPreferredName(), text)
+                .field(TYPE_FIELD.getPreferredName(), type.name().toLowerCase(Locale.ROOT))
+                .field(LANG_FIELD.getPreferredName(), lang)
+                .field(PARAMS_FIELD.getPreferredName(), this.params)
+                .endObject();
+    }
+
+    /**
+     */
+    public static class Parser extends AbstractComponent implements Template.Parser<ScriptTemplate> {
+
+        private final ScriptServiceProxy scriptService;
+
+        @Inject
+        public Parser(Settings settings, ScriptServiceProxy scriptService) {
+            super(settings);
+            this.scriptService = scriptService;
+        }
+
+        @Override
+        public ScriptTemplate parse(XContentParser parser) throws IOException {
+            assert parser.currentToken() == XContentParser.Token.START_OBJECT : "Expected START_OBJECT, but was " + parser.currentToken();
+
+            String text = null;
+            ScriptService.ScriptType type = ScriptService.ScriptType.INLINE;
+            String lang = DEFAULT_LANG;
+            ImmutableMap.Builder<String, Object> params = ImmutableMap.builder();
+
+            String currentFieldName = null;
+            XContentParser.Token token;
+            while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+                if (token == XContentParser.Token.FIELD_NAME) {
+                    currentFieldName = parser.currentName();
+                } else if (TEXT_FIELD.match(currentFieldName)) {
+                    if (token.isValue()) {
+                        text = parser.text();
+                    } else {
+                        throw new ParseException("expected a string value for [" + currentFieldName + "], but found [" + token + "] instead");
+                    }
+                } else if (LANG_FIELD.match(currentFieldName)) {
+                    if (token == XContentParser.Token.VALUE_STRING) {
+                        lang = parser.text();
+                    } else {
+                        throw new ParseException("expected a string value for [" + currentFieldName + "], but found [" + token + "] instead");
+                    }
+                } else if (TYPE_FIELD.match(currentFieldName)) {
+                    if (token == XContentParser.Token.VALUE_STRING) {
+                        String value = parser.text();
+                        try {
+                            type = ScriptService.ScriptType.valueOf(value.toUpperCase(Locale.ROOT));
+                        } catch (IllegalArgumentException iae) {
+                            String typeOptions = Joiner.on(",").join(Collections2.transform(ImmutableList.copyOf(ScriptService.ScriptType.values()), new Function<ScriptService.ScriptType, String>() {
+                                @Override
+                                public String apply(ScriptService.ScriptType scriptType) {
+                                    return scriptType.name().toLowerCase(Locale.ROOT);
+                                }
+                            }));
+                            throw new ParseException("unknown template script type [" + currentFieldName + "]. type can only be on of: [" + typeOptions + "]");
+                        }
+                    }
+                } else if (PARAMS_FIELD.match(currentFieldName)) {
+                    if (token != XContentParser.Token.START_OBJECT) {
+                        throw new ParseException("expected an object for [" + currentFieldName + "], but found [" + token + "]");
+                    }
+                    params.putAll(parser.map());
+                } else {
+                    throw new ParseException("unexpected field [" + currentFieldName + "]");
+                }
+            }
+            if (text == null) {
+                throw new ParseException("missing required field [" + TEXT_FIELD.getPreferredName() + "]");
+            }
+            return new ScriptTemplate(scriptService, text, lang, type, params.build());
+        }
+    }
+
+}

src/main/java/org/elasticsearch/alerts/support/template/Template.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.alerts.support.template;
+
+import org.elasticsearch.alerts.AlertsException;
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentParser;
+
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ *
+ */
+public interface Template extends ToXContent {
+
+    String render(Map<String, Object> model);
+
+    interface Parser<T extends Template> {
+
+        T parse(XContentParser parser) throws IOException, ParseException;
+
+        public static class ParseException extends AlertsException {
+
+            public ParseException(String msg) {
+                super(msg);
+            }
+        }
+
+    }
+}

src/main/java/org/elasticsearch/alerts/support/template/TemplateException.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.alerts.support.template;
+
+import org.elasticsearch.alerts.AlertsException;
+
+/**
+ *
+ */
+public class TemplateException extends AlertsException {
+
+    public TemplateException(String msg) {
+        super(msg);
+    }
+
+    public TemplateException(String msg, Throwable cause) {
+        super(msg, cause);
+    }
+}

src/main/java/org/elasticsearch/alerts/support/template/TemplateModule.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.alerts.support.template;
+
+import org.elasticsearch.common.inject.AbstractModule;
+
+/**
+ *
+ */
+public class TemplateModule extends AbstractModule {
+
+    @Override
+    protected void configure() {
+        bind(Template.Parser.class).to(ScriptTemplate.Parser.class).asEagerSingleton();
+    }
+}

src/main/java/org/elasticsearch/alerts/support/template/XContentTemplate.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.alerts.support.template;
+
+import org.elasticsearch.common.xcontent.XContent;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.yaml.YamlXContent;
+
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ *
+ */
+public class XContentTemplate implements Template {
+
+    public static XContentTemplate YAML = new XContentTemplate(YamlXContent.yamlXContent);
+
+    private final XContent xContent;
+
+    private XContentTemplate(XContent xContent) {
+        this.xContent = xContent;
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        return builder.startObject().endObject();
+    }
+
+    @Override
+    public String render(Map<String, Object> model) {
+        try {
+            return XContentBuilder.builder(xContent).map(model).bytes().toUtf8();
+        } catch (IOException ioe) {
+            throw new TemplateException("could not render [" + xContent.type().name() + "] xcontent template", ioe);
+        }
+    }
+
+}

src/test/java/org/elasticsearch/alerts/AbstractAlertingTests.java

@@ -24,9 +24,10 @@ import org.elasticsearch.alerts.history.FiredAlert;
 import org.elasticsearch.alerts.history.HistoryStore;
 import org.elasticsearch.alerts.scheduler.schedule.CronSchedule;
 import org.elasticsearch.alerts.support.AlertUtils;
-import org.elasticsearch.alerts.support.StringTemplateUtils;
 import org.elasticsearch.alerts.support.init.proxy.ClientProxy;
 import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
+import org.elasticsearch.alerts.support.template.ScriptTemplate;
+import org.elasticsearch.alerts.support.template.Template;
 import org.elasticsearch.alerts.transform.SearchTransform;
 import org.elasticsearch.alerts.transport.actions.stats.AlertsStatsResponse;
 import org.elasticsearch.client.Client;
@@ -162,10 +163,10 @@ public abstract class AbstractAlertingTests extends ElasticsearchIntegrationTest
 
         List<Action> actions = new ArrayList<>();
 
-        StringTemplateUtils.Template template =
+        Template url = new ScriptTemplate(scriptService(), "http://localhost/foobarbaz/{{alert_name}}");
-                new StringTemplateUtils.Template("{{alert_name}} executed with {{response.hits.total}} hits");
+        Template body = new ScriptTemplate(scriptService(), "{{alert_name}} executed with {{response.hits.total}} hits");
 
-        actions.add(new WebhookAction(logger, stringTemplateUtils(), httpClient(), template, new StringTemplateUtils.Template("http://localhost/foobarbaz/{{alert_name}}"), HttpMethod.GET));
+        actions.add(new WebhookAction(logger, httpClient(), HttpMethod.GET, url, body));
 
         Email.Address from = new Email.Address("from@test.com");
         List<Email.Address> emailAddressList = new ArrayList<>();
@@ -178,8 +179,8 @@ public abstract class AbstractAlertingTests extends ElasticsearchIntegrationTest
         emailBuilder.to(to);
 
 
-        EmailAction emailAction = new EmailAction(logger, noopEmailService(), stringTemplateUtils(), emailBuilder,
+        EmailAction emailAction = new EmailAction(logger, noopEmailService(), emailBuilder,
-                new Authentication("testname", "testpassword"), Profile.STANDARD, "testaccount", template, template, null, true);
+                new Authentication("testname", "testpassword"), Profile.STANDARD, "testaccount", body, body, null, true);
 
         actions.add(emailAction);
 
@@ -189,9 +190,9 @@ public abstract class AbstractAlertingTests extends ElasticsearchIntegrationTest
         return new Alert(
                 alertName,
                 new CronSchedule("0/5 * * * * ? *"),
-                new ScriptSearchCondition(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()),
+                new ScriptSearchCondition(logger, scriptService(), ClientProxy.of(client()),
                         conditionRequest,"return true", ScriptService.ScriptType.INLINE, "groovy"),
-                new SearchTransform(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()), transformRequest),
+                new SearchTransform(logger, scriptService(), ClientProxy.of(client()), transformRequest),
                 new TimeValue(0),
                 new Actions(actions),
                 metadata,
@@ -204,8 +205,12 @@ public abstract class AbstractAlertingTests extends ElasticsearchIntegrationTest
         return internalTestCluster().getInstance(AlertsClient.class);
     }
 
-    protected ScriptService scriptService() {
+    protected ScriptServiceProxy scriptService() {
-        return internalTestCluster().getInstance(ScriptService.class);
+        return internalTestCluster().getInstance(ScriptServiceProxy.class);
+    }
+
+    protected Template.Parser templateParser() {
+        return internalTestCluster().getInstance(Template.Parser.class);
     }
 
     protected HttpClient httpClient() {
@@ -216,10 +221,6 @@ public abstract class AbstractAlertingTests extends ElasticsearchIntegrationTest
         return new NoopEmailService();
     }
 
-    protected StringTemplateUtils stringTemplateUtils() {
-        return internalTestCluster().getInstance(StringTemplateUtils.class);
-    }
-
     protected FiredAlert.Parser firedAlertParser() {
         return internalTestCluster().getInstance(FiredAlert.Parser.class);
     }

src/test/java/org/elasticsearch/alerts/AlertThrottleTests.java

@@ -15,16 +15,15 @@ import org.elasticsearch.alerts.actions.Action;
 import org.elasticsearch.alerts.actions.Actions;
 import org.elasticsearch.alerts.actions.index.IndexAction;
 import org.elasticsearch.alerts.client.AlertsClient;
+import org.elasticsearch.alerts.condition.search.ScriptSearchCondition;
 import org.elasticsearch.alerts.history.FiredAlert;
 import org.elasticsearch.alerts.history.HistoryStore;
 import org.elasticsearch.alerts.scheduler.schedule.CronSchedule;
 import org.elasticsearch.alerts.support.init.proxy.ClientProxy;
-import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
 import org.elasticsearch.alerts.transform.SearchTransform;
 import org.elasticsearch.alerts.transport.actions.ack.AckAlertResponse;
 import org.elasticsearch.alerts.transport.actions.get.GetAlertResponse;
 import org.elasticsearch.alerts.transport.actions.put.PutAlertResponse;
-import org.elasticsearch.alerts.condition.search.ScriptSearchCondition;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -40,9 +39,7 @@ import java.util.concurrent.TimeUnit;
 
 import static org.elasticsearch.index.query.QueryBuilders.matchAllQuery;
 import static org.elasticsearch.search.builder.SearchSourceBuilder.searchSource;
-import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.*;
-import static org.hamcrest.Matchers.greaterThanOrEqualTo;
-import static org.hamcrest.Matchers.lessThanOrEqualTo;
 import static org.hamcrest.core.IsEqual.equalTo;
 
 /**
@@ -69,9 +66,9 @@ public class AlertThrottleTests extends AbstractAlertingTests {
         Alert alert = new Alert(
                 "test-serialization",
                 new CronSchedule("0/5 * * * * ? *"),
-                new ScriptSearchCondition(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()),
+                new ScriptSearchCondition(logger, scriptService(), ClientProxy.of(client()),
                         request, "hits.total > 0", ScriptService.ScriptType.INLINE, "groovy"),
-                new SearchTransform(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()), request),
+                new SearchTransform(logger, scriptService(), ClientProxy.of(client()), request),
                 new TimeValue(0),
                 new Actions(actions),
                 null,
@@ -152,9 +149,9 @@ public class AlertThrottleTests extends AbstractAlertingTests {
         Alert alert = new Alert(
                 "test-time-throttle",
                 new CronSchedule("0/5 * * * * ? *"),
-                new ScriptSearchCondition(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()),
+                new ScriptSearchCondition(logger, scriptService(), ClientProxy.of(client()),
                         request, "hits.total > 0", ScriptService.ScriptType.INLINE, "groovy"),
-                new SearchTransform(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()), request),
+                new SearchTransform(logger, scriptService(), ClientProxy.of(client()), request),
                 new TimeValue(10, TimeUnit.SECONDS),
                 new Actions(actions),
                 null,

src/test/java/org/elasticsearch/alerts/BootStrapTest.java

@@ -16,7 +16,6 @@ import org.elasticsearch.alerts.history.FiredAlert;
 import org.elasticsearch.alerts.history.HistoryStore;
 import org.elasticsearch.alerts.scheduler.schedule.CronSchedule;
 import org.elasticsearch.alerts.support.init.proxy.ClientProxy;
-import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
 import org.elasticsearch.alerts.transform.SearchTransform;
 import org.elasticsearch.alerts.transport.actions.put.PutAlertResponse;
 import org.elasticsearch.alerts.transport.actions.stats.AlertsStatsResponse;
@@ -80,9 +79,9 @@ public class BootStrapTest extends AbstractAlertingTests {
         Alert alert = new Alert(
                 "test-serialization",
                 new CronSchedule("0/5 * * * * ? 2035"),
-                new ScriptSearchCondition(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()),
+                new ScriptSearchCondition(logger, scriptService(), ClientProxy.of(client()),
                         searchRequest, "return true", ScriptService.ScriptType.INLINE, "groovy"),
-                new SearchTransform(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()), searchRequest),
+                new SearchTransform(logger, scriptService(), ClientProxy.of(client()), searchRequest),
                 new TimeValue(0),
                 new Actions(new ArrayList<Action>()),
                 null,
@@ -140,9 +139,9 @@ public class BootStrapTest extends AbstractAlertingTests {
                 Alert alert = new Alert(
                         "action-test-"+ i + " " + j,
                         new CronSchedule("0/5 * * * * ? 2035"), //Set a cron schedule far into the future so this alert is never scheduled
-                        new ScriptSearchCondition(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()),
+                        new ScriptSearchCondition(logger, scriptService(), ClientProxy.of(client()),
                                 searchRequest, "return true", ScriptService.ScriptType.INLINE, "groovy"),
-                        new SearchTransform(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()), searchRequest),
+                        new SearchTransform(logger, scriptService(), ClientProxy.of(client()), searchRequest),
                         new TimeValue(0),
                         new Actions(new ArrayList<Action>()),
                         null,

src/test/java/org/elasticsearch/alerts/TransformSearchTest.java

@@ -13,7 +13,6 @@ import org.elasticsearch.alerts.actions.index.IndexAction;
 import org.elasticsearch.alerts.condition.search.ScriptSearchCondition;
 import org.elasticsearch.alerts.scheduler.schedule.CronSchedule;
 import org.elasticsearch.alerts.support.init.proxy.ClientProxy;
-import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
 import org.elasticsearch.alerts.transform.SearchTransform;
 import org.elasticsearch.alerts.transport.actions.put.PutAlertResponse;
 import org.elasticsearch.common.unit.TimeValue;
@@ -59,9 +58,9 @@ public class TransformSearchTest extends AbstractAlertingTests {
         Alert alert = new Alert(
                 "test-serialization",
                 new CronSchedule("0/5 * * * * ? *"),
-                new ScriptSearchCondition(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()),
+                new ScriptSearchCondition(logger, scriptService(), ClientProxy.of(client()),
                         conditionRequest,"return true", ScriptService.ScriptType.INLINE, "groovy"),
-                new SearchTransform(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()), transformRequest),
+                new SearchTransform(logger, scriptService(), ClientProxy.of(client()), transformRequest),
                 new TimeValue(0),
                 new Actions(actions),
                 metadata,

src/test/java/org/elasticsearch/alerts/actions/ActionsTest.java

@@ -9,9 +9,10 @@ package org.elasticsearch.alerts.actions;
 import org.elasticsearch.alerts.AbstractAlertingTests;
 import org.elasticsearch.alerts.Alert;
 import org.elasticsearch.alerts.actions.index.IndexAction;
+import org.elasticsearch.alerts.condition.Condition;
+import org.elasticsearch.alerts.condition.search.ScriptSearchCondition;
 import org.elasticsearch.alerts.scheduler.schedule.CronSchedule;
 import org.elasticsearch.alerts.support.init.proxy.ClientProxy;
-import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
 import org.elasticsearch.alerts.transform.SearchTransform;
 import org.elasticsearch.alerts.transport.actions.delete.DeleteAlertRequest;
 import org.elasticsearch.alerts.transport.actions.delete.DeleteAlertResponse;
@@ -19,8 +20,6 @@ import org.elasticsearch.alerts.transport.actions.get.GetAlertRequest;
 import org.elasticsearch.alerts.transport.actions.get.GetAlertResponse;
 import org.elasticsearch.alerts.transport.actions.put.PutAlertRequest;
 import org.elasticsearch.alerts.transport.actions.put.PutAlertResponse;
-import org.elasticsearch.alerts.condition.Condition;
-import org.elasticsearch.alerts.condition.search.ScriptSearchCondition;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -57,7 +56,7 @@ public class ActionsTest extends AbstractAlertingTests {
         final List<Action> actionList = new ArrayList<>();
         actionList.add(alertAction);
 
-        Condition alertCondition = new ScriptSearchCondition(logger, ScriptServiceProxy.of(scriptService()),
+        Condition alertCondition = new ScriptSearchCondition(logger, scriptService(),
                 ClientProxy.of(client()), createConditionSearchRequest(), "return true", ScriptService.ScriptType.INLINE, "groovy");
 
 
@@ -65,7 +64,7 @@ public class ActionsTest extends AbstractAlertingTests {
                 "my-first-alert",
                 new CronSchedule("0/5 * * * * ? *"),
                 alertCondition,
-                new SearchTransform(logger, ScriptServiceProxy.of(scriptService()), ClientProxy.of(client()), createConditionSearchRequest()),
+                new SearchTransform(logger, scriptService(), ClientProxy.of(client()), createConditionSearchRequest()),
                 new TimeValue(0),
                 new Actions(actionList),
                 null,

src/test/java/org/elasticsearch/alerts/actions/email/EmailActionTest.java

@@ -13,8 +13,8 @@ import org.elasticsearch.alerts.actions.email.service.Email;
 import org.elasticsearch.alerts.actions.email.service.EmailService;
 import org.elasticsearch.alerts.actions.email.service.Profile;
 import org.elasticsearch.alerts.scheduler.schedule.CronSchedule;
-import org.elasticsearch.alerts.support.StringTemplateUtils;
 import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
+import org.elasticsearch.alerts.support.template.ScriptTemplate;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.common.joda.time.DateTime;
 import org.elasticsearch.common.settings.ImmutableSettings;
@@ -40,8 +40,6 @@ import java.util.Set;
 public class EmailActionTest extends ElasticsearchTestCase {
 
     public void testEmailTemplateRender() throws IOException, MessagingException {
-        StringTemplateUtils.Template template =
-                new StringTemplateUtils.Template("{{alert_name}} executed with {{response.hits.total}} hits");
 
         Settings settings = ImmutableSettings.settingsBuilder().build();
         MustacheScriptEngineService mustacheScriptEngineService = new MustacheScriptEngineService(settings);
@@ -49,8 +47,9 @@ public class EmailActionTest extends ElasticsearchTestCase {
         Set<ScriptEngineService> engineServiceSet = new HashSet<>();
         engineServiceSet.add(mustacheScriptEngineService);
 
-        ScriptService scriptService = new ScriptService(settings, new Environment(), engineServiceSet, new ResourceWatcherService(settings, threadPool));
+        ScriptServiceProxy scriptService = ScriptServiceProxy.of(new ScriptService(settings, new Environment(), engineServiceSet, new ResourceWatcherService(settings, threadPool)));
-        StringTemplateUtils stringTemplateUtils = new StringTemplateUtils(settings, ScriptServiceProxy.of(scriptService));
+
+        ScriptTemplate template = new ScriptTemplate(scriptService, "{{alert_name}} executed with {{response.hits.total}} hits");
 
         EmailService emailService = new EmailServiceMock();
 
@@ -64,7 +63,7 @@ public class EmailActionTest extends ElasticsearchTestCase {
         emailBuilder.from(from);
         emailBuilder.to(to);
 
-        EmailAction emailAction = new EmailAction(logger, emailService, stringTemplateUtils, emailBuilder,
+        EmailAction emailAction = new EmailAction(logger, emailService, emailBuilder,
                 new Authentication("testname", "testpassword"), Profile.STANDARD, "testaccount", template, template, null, true);
 
         //This is ok since the execution of the action only relies on the alert name

src/test/java/org/elasticsearch/alerts/actions/webhook/WebhookTest.java

@@ -1,50 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License;
- * you may not use this file except in compliance with the Elastic License.
- */
-package org.elasticsearch.alerts.actions.webhook;
-
-import org.elasticsearch.alerts.support.StringTemplateUtils;
-import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
-import org.elasticsearch.common.settings.ImmutableSettings;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.env.Environment;
-import org.elasticsearch.script.ScriptEngineService;
-import org.elasticsearch.script.ScriptService;
-import org.elasticsearch.script.mustache.MustacheScriptEngineService;
-import org.elasticsearch.test.ElasticsearchTestCase;
-import org.elasticsearch.threadpool.ThreadPool;
-import org.elasticsearch.watcher.ResourceWatcherService;
-
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-
-/**
- */
-public class WebhookTest extends ElasticsearchTestCase {
-
-    public void testRequestParameterSerialization() throws Exception {
-
-        Map<String, Object> responseMap = new HashMap<>();
-        responseMap.put("hits",0);
-
-        Settings settings = ImmutableSettings.settingsBuilder().build();
-        MustacheScriptEngineService mustacheScriptEngineService = new MustacheScriptEngineService(settings);
-        ThreadPool tp;
-        tp = new ThreadPool(ThreadPool.Names.SAME);
-        Set<ScriptEngineService> engineServiceSet = new HashSet<>();
-        engineServiceSet.add(mustacheScriptEngineService);
-        ScriptService scriptService = new ScriptService(settings, new Environment(), engineServiceSet, new ResourceWatcherService(settings, tp));
-
-        StringTemplateUtils.Template testTemplate = new StringTemplateUtils.Template("{ 'alertname' : '{{alert_name}}', 'response' : { 'hits' : {{response.hits}} } }");
-        String testBody = WebhookAction.applyTemplate(new StringTemplateUtils(settings, ScriptServiceProxy.of(scriptService)), testTemplate, "foobar", responseMap);
-
-        tp.shutdownNow();
-        assertEquals("{ 'alertname' : 'foobar', 'response' : { 'hits' : 0 } }", testBody);
-
-
-    }
-}

src/test/java/org/elasticsearch/alerts/support/template/ScriptTemplateTests.java

@@ -0,0 +1,171 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.alerts.support.template;
+
+import org.elasticsearch.alerts.support.init.proxy.ScriptServiceProxy;
+import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.collect.ImmutableMap;
+import org.elasticsearch.common.settings.ImmutableSettings;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.common.xcontent.json.JsonXContent;
+import org.elasticsearch.script.ExecutableScript;
+import org.elasticsearch.script.ScriptService;
+import org.elasticsearch.test.ElasticsearchTestCase;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Map;
+
+import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.hamcrest.Matchers.*;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ *
+ */
+public class ScriptTemplateTests extends ElasticsearchTestCase {
+
+    private ScriptServiceProxy proxy;
+    private ExecutableScript script;
+
+    @Before
+    public void init() throws Exception {
+        proxy = mock(ScriptServiceProxy.class);
+        script = mock(ExecutableScript.class);
+    }
+
+    @Test
+    public void testRender() throws Exception {
+        String lang = "_lang";
+        String templateText = "_template";
+        Map<String, Object> params = ImmutableMap.<String, Object>of("param_key", "param_val");
+        Map<String, Object> model = ImmutableMap.<String, Object>of("model_key", "model_val");
+        Map<String, Object> merged = ImmutableMap.<String, Object>builder().putAll(params).putAll(model).build();
+        ScriptService.ScriptType scriptType = ScriptService.ScriptType.values()[randomIntBetween(0, ScriptService.ScriptType.values().length - 1)];
+
+        when(script.run()).thenReturn("rendered_text");
+        when(proxy.executable(lang, templateText, scriptType, merged)).thenReturn(script);
+
+        ScriptTemplate template = new ScriptTemplate(proxy, templateText, lang, scriptType, params);
+        assertThat(template.render(model), is("rendered_text"));
+    }
+
+    @Test
+    public void testRender_OverridingModel() throws Exception {
+        String lang = "_lang";
+        String templateText = "_template";
+        Map<String, Object> params = ImmutableMap.<String, Object>of("key", "param_val");
+        Map<String, Object> model = ImmutableMap.<String, Object>of("key", "model_val");
+        ScriptService.ScriptType scriptType = randomScriptType();
+
+
+        when(script.run()).thenReturn("rendered_text");
+        when(proxy.executable(lang, templateText, scriptType, model)).thenReturn(script);
+
+        ScriptTemplate template = new ScriptTemplate(proxy, templateText, lang, scriptType, params);
+        assertThat(template.render(model), is("rendered_text"));
+    }
+
+    @Test
+    public void testRender_Defaults() throws Exception {
+        String templateText = "_template";
+        Map<String, Object> model = ImmutableMap.<String, Object>of("key", "model_val");
+
+        when(script.run()).thenReturn("rendered_text");
+        when(proxy.executable(ScriptTemplate.DEFAULT_LANG, templateText, ScriptService.ScriptType.INLINE, model)).thenReturn(script);
+
+        ScriptTemplate template = new ScriptTemplate(proxy, templateText);
+        assertThat(template.render(model), is("rendered_text"));
+    }
+
+    @Test
+    public void testParser() throws Exception {
+        ScriptTemplate.Parser templateParser = new ScriptTemplate.Parser(ImmutableSettings.EMPTY, proxy);
+
+        ScriptTemplate template = new ScriptTemplate(proxy, "_template", "_lang", randomScriptType(), ImmutableMap.<String, Object>of("param_key", "param_val"));
+
+        XContentBuilder builder = jsonBuilder().startObject()
+                .field(randomFrom("lang", "script_lang"), template.lang())
+                .field(randomFrom("script", "text"), template.text())
+                .field(randomFrom("type", "script_type"), template.type().name())
+                .field(randomFrom("params", "model"), template.params())
+                .endObject();
+        BytesReference bytes = builder.bytes();
+        XContentParser parser = JsonXContent.jsonXContent.createParser(bytes);
+        parser.nextToken();
+        ScriptTemplate parsed = templateParser.parse(parser);
+        assertThat(parsed, notNullValue());
+        assertThat(parsed, equalTo(template));
+    }
+
+    @Test
+    public void testParser_ParserSelfGenerated() throws Exception {
+        ScriptTemplate.Parser templateParser = new ScriptTemplate.Parser(ImmutableSettings.EMPTY, proxy);
+
+        ScriptTemplate template = new ScriptTemplate(proxy, "_template", "_lang", randomScriptType(), ImmutableMap.<String, Object>of("param_key", "param_val"));
+
+        XContentBuilder builder = jsonBuilder().value(template);
+        BytesReference bytes = builder.bytes();
+        XContentParser parser = JsonXContent.jsonXContent.createParser(bytes);
+        parser.nextToken();
+        ScriptTemplate parsed = templateParser.parse(parser);
+        assertThat(parsed, notNullValue());
+        assertThat(parsed, equalTo(template));
+    }
+
+    @Test(expected = Template.Parser.ParseException.class)
+    public void testParser_Invalid_UnexpectedField() throws Exception {
+        ScriptTemplate.Parser templateParser = new ScriptTemplate.Parser(ImmutableSettings.EMPTY, proxy);
+
+        XContentBuilder builder = jsonBuilder().startObject()
+                .field("unknown_field", "value")
+                .endObject();
+        BytesReference bytes = builder.bytes();
+        XContentParser parser = JsonXContent.jsonXContent.createParser(bytes);
+        parser.nextToken();
+        templateParser.parse(parser);
+        fail("expected parse exception when encountering an unknown field");
+    }
+
+    @Test(expected = Template.Parser.ParseException.class)
+    public void testParser_Invalid_UnknownScriptType() throws Exception {
+        ScriptTemplate.Parser templateParser = new ScriptTemplate.Parser(ImmutableSettings.EMPTY, proxy);
+
+        XContentBuilder builder = jsonBuilder().startObject()
+                .field("lang", ScriptTemplate.DEFAULT_LANG)
+                .field("script", "_template")
+                .field("type", "unknown_type")
+                .startObject("params").endObject()
+                .endObject();
+        BytesReference bytes = builder.bytes();
+        XContentParser parser = JsonXContent.jsonXContent.createParser(bytes);
+        parser.nextToken();
+        templateParser.parse(parser);
+        fail("expected parse exception when script type is unknown");
+    }
+
+    @Test(expected = Template.Parser.ParseException.class)
+    public void testParser_Invalid_MissingScript() throws Exception {
+        ScriptTemplate.Parser templateParser = new ScriptTemplate.Parser(ImmutableSettings.EMPTY, proxy);
+
+        XContentBuilder builder = jsonBuilder().startObject()
+                .field("lang", ScriptTemplate.DEFAULT_LANG)
+                .field("type", ScriptService.ScriptType.INDEXED)
+                .startObject("params").endObject()
+                .endObject();
+        BytesReference bytes = builder.bytes();
+        XContentParser parser = JsonXContent.jsonXContent.createParser(bytes);
+        parser.nextToken();
+        templateParser.parse(parser);
+        fail("expected parse exception when template text is missing");
+    }
+
+    private static ScriptService.ScriptType randomScriptType() {
+        return randomFrom(ScriptService.ScriptType.values());
+    }
+}

src/test/java/org/elasticsearch/alerts/support/template/XContentTemplateTests.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.alerts.support.template;
+
+import org.elasticsearch.common.bytes.BytesArray;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.common.xcontent.yaml.YamlXContent;
+import org.elasticsearch.test.ElasticsearchTestCase;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+
+/**
+ *
+ */
+public class XContentTemplateTests extends ElasticsearchTestCase {
+
+    @Test
+    public void testYaml() throws Exception {
+        Map<String, Object> model = new HashMap<>();
+        Map<String, Object> a = new HashMap<>();
+        a.put("aa", "aa");
+        a.put("ab", "ab");
+        model.put("a", a);
+        Map<String, Object> b = new HashMap<>();
+        b.put("ba", 21);
+        model.put("b", b);
+        model.put("c", "c");
+
+        String text = XContentTemplate.YAML.render(model);
+
+        // now lets read it as xcontent and make sure it has all the pieces
+        XContentParser parser = YamlXContent.yamlXContent.createParser(new BytesArray(text));
+        XContentParser.Token token = parser.nextToken();
+        assertThat(token, is(XContentParser.Token.START_OBJECT));
+        String currentFieldName = null;
+        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+            if (token == XContentParser.Token.FIELD_NAME) {
+                currentFieldName = parser.currentName();
+            } else if ("a".equals(currentFieldName)) {
+                assertThat(token, is(XContentParser.Token.START_OBJECT));
+                while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+                    if (token == XContentParser.Token.FIELD_NAME) {
+                        currentFieldName = parser.currentName();
+                    } else {
+                        assertThat(token, is(XContentParser.Token.VALUE_STRING));
+                        if ("aa".equals(currentFieldName)) {
+                            assertThat(parser.text(), equalTo("aa"));
+                        } else if ("ab".equals(currentFieldName)) {
+                            assertThat(parser.text(), equalTo("ab"));
+                        } else {
+                            fail("unexpected field name [" + currentFieldName + "]");
+                        }
+                    }
+                }
+            } else if ("b".equals(currentFieldName)) {
+                assertThat(token, is(XContentParser.Token.START_OBJECT));
+                while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+                    if (token == XContentParser.Token.FIELD_NAME) {
+                        currentFieldName = parser.currentName();
+                    } else {
+                        assertThat(token, is(XContentParser.Token.VALUE_NUMBER));
+                        assertThat(currentFieldName, equalTo("ba"));
+                        assertThat(parser.intValue(), is(21));
+                    }
+                }
+            } else if ("c".equals(currentFieldName)) {
+                assertThat(token, is(XContentParser.Token.VALUE_STRING));
+                assertThat(parser.text(), equalTo("c"));
+            } else {
+                fail("unexpected field [" + currentFieldName + "]");
+            }
+        }
+    }
+}