ingest: compile mustache template only if field includes '{{'' (#37207)

* ingest: compile mustache template only if field includes '{{''

Prior to this change, any field in an ingest node processor that supports
script templates would be compiled as mustache template regardless if they
contain a template or not. Compiling normal text as mustache templates is
harmless. However, each compilation counts against the script compilation
circuit breaker. A large number of processors without any templates or scripts
could un-intuitively trip the too many script compilations circuit breaker.

This change simple checks for '{{' in the text before it attempts to compile.

fixes #37120

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/AppendProcessorFactoryTests.java

@@ -95,7 +95,7 @@ public class AppendProcessorFactoryTests extends ESTestCase {
     public void testInvalidMustacheTemplate() throws Exception {
         AppendProcessor.Factory factory = new AppendProcessor.Factory(TestTemplateService.instance(true));
         Map<String, Object> config = new HashMap<>();
-        config.put("field", "field1");
+        config.put("field", "{{field1}}");
         config.put("value", "value1");
         String processorTag = randomAlphaOfLength(10);
         ElasticsearchException exception = expectThrows(ElasticsearchException.class, () -> factory.create(null, processorTag, config));

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/FailProcessorFactoryTests.java

@@ -62,7 +62,7 @@ public class FailProcessorFactoryTests extends ESTestCase {
     public void testInvalidMustacheTemplate() throws Exception {
         FailProcessor.Factory factory = new FailProcessor.Factory(TestTemplateService.instance(true));
         Map<String, Object> config = new HashMap<>();
-        config.put("message", "error");
+        config.put("message", "{{error}}");
         String processorTag = randomAlphaOfLength(10);
         ElasticsearchException exception = expectThrows(ElasticsearchException.class, () -> factory.create(null, processorTag, config));
         assertThat(exception.getMessage(), equalTo("java.lang.RuntimeException: could not compile script"));

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/RemoveProcessorFactoryTests.java

@@ -75,7 +75,7 @@ public class RemoveProcessorFactoryTests extends ESTestCase {
     public void testInvalidMustacheTemplate() throws Exception {
         RemoveProcessor.Factory factory = new RemoveProcessor.Factory(TestTemplateService.instance(true));
         Map<String, Object> config = new HashMap<>();
-        config.put("field", "field1");
+        config.put("field", "{{field1}}");
         String processorTag = randomAlphaOfLength(10);
         ElasticsearchException exception = expectThrows(ElasticsearchException.class, () -> factory.create(null, processorTag, config));
         assertThat(exception.getMessage(), equalTo("java.lang.RuntimeException: could not compile script"));

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/SetProcessorFactoryTests.java

@@ -103,7 +103,7 @@ public class SetProcessorFactoryTests extends ESTestCase {
     public void testInvalidMustacheTemplate() throws Exception {
         SetProcessor.Factory factory = new SetProcessor.Factory(TestTemplateService.instance(true));
         Map<String, Object> config = new HashMap<>();
-        config.put("field", "field1");
+        config.put("field", "{{field1}}");
         config.put("value", "value1");
         String processorTag = randomAlphaOfLength(10);
         ElasticsearchException exception = expectThrows(ElasticsearchException.class, () -> factory.create(null, processorTag, config));

server/src/main/java/org/elasticsearch/ingest/ConfigurationUtils.java

@@ -335,7 +335,7 @@ public final class ConfigurationUtils {
             // installed for use by REST tests. `propertyValue` will not be
             // modified if templating is not available so a script that simply returns an unmodified `propertyValue`
             // is returned.
-            if (scriptService.isLangSupported(DEFAULT_TEMPLATE_LANG)) {
+            if (scriptService.isLangSupported(DEFAULT_TEMPLATE_LANG) && propertyValue.contains("{{")) {
                 Script script = new Script(ScriptType.INLINE, DEFAULT_TEMPLATE_LANG, propertyValue, Collections.emptyMap());
                 return scriptService.compile(script, TemplateScript.CONTEXT);
             } else {

server/src/main/java/org/elasticsearch/ingest/ValueSource.java

@@ -75,7 +75,7 @@ public interface ValueSource {
             // This check is here because the DEFAULT_TEMPLATE_LANG(mustache) is not
             // installed for use by REST tests. `value` will not be
             // modified if templating is not available
-            if (scriptService.isLangSupported(DEFAULT_TEMPLATE_LANG)) {
+            if (scriptService.isLangSupported(DEFAULT_TEMPLATE_LANG) && ((String) value).contains("{{")) {
                 Script script = new Script(ScriptType.INLINE, DEFAULT_TEMPLATE_LANG, (String) value, Collections.emptyMap());
                 return new TemplatedValue(scriptService.compile(script, TemplateScript.CONTEXT));
             } else {

server/src/test/java/org/elasticsearch/ingest/ConfigurationUtilsTests.java

@@ -21,6 +21,7 @@ package org.elasticsearch.ingest;
 
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.script.ScriptService;
+import org.elasticsearch.script.TemplateScript;
 import org.elasticsearch.test.ESTestCase;
 import org.junit.Before;
 
@@ -36,7 +37,12 @@ import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.nullValue;
 import static org.hamcrest.Matchers.sameInstance;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyString;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 public class ConfigurationUtilsTests extends ESTestCase {
 
@@ -181,4 +187,27 @@ public class ConfigurationUtilsTests extends ESTestCase {
         assertThat(ex.getMessage(), equalTo("property isn't a map, but of type [" + invalidConfig.getClass().getName() + "]"));
     }
 
+    public void testNoScriptCompilation() {
+        ScriptService scriptService = mock(ScriptService.class);
+        when(scriptService.isLangSupported(anyString())).thenReturn(true);
+        String propertyValue = randomAlphaOfLength(10);
+        TemplateScript.Factory result;
+        result = ConfigurationUtils.compileTemplate(randomAlphaOfLength(10), randomAlphaOfLength(10), randomAlphaOfLength(10),
+            propertyValue, scriptService);
+        assertThat(result.newInstance(null).execute(), equalTo(propertyValue));
+        verify(scriptService, times(0)).compile(any(), any());
+    }
+
+    public void testScriptShouldCompile() {
+        ScriptService scriptService = mock(ScriptService.class);
+        when(scriptService.isLangSupported(anyString())).thenReturn(true);
+        String propertyValue = "{{" + randomAlphaOfLength(10) + "}}";
+        String compiledValue = randomAlphaOfLength(10);
+        when(scriptService.compile(any(), any())).thenReturn(new TestTemplateService.MockTemplateScript.Factory(compiledValue));
+        TemplateScript.Factory result;
+        result = ConfigurationUtils.compileTemplate(randomAlphaOfLength(10), randomAlphaOfLength(10), randomAlphaOfLength(10),
+            propertyValue, scriptService);
+        assertThat(result.newInstance(null).execute(), equalTo(compiledValue));
+        verify(scriptService, times(1)).compile(any(), any());
+    }
 }

server/src/test/java/org/elasticsearch/ingest/ValueSourceTests.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.ingest;
 
+import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.test.ESTestCase;
 
 import java.util.ArrayList;
@@ -30,6 +31,12 @@ import java.util.Map;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.not;
 import static org.hamcrest.Matchers.sameInstance;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 public class ValueSourceTests extends ESTestCase {
 
@@ -69,4 +76,24 @@ public class ValueSourceTests extends ESTestCase {
         assertThat(myPreciousList.size(), equalTo(1));
         assertThat(myPreciousList.get(0), equalTo("value"));
     }
+
+    public void testNoScriptCompilation() {
+        ScriptService scriptService = mock(ScriptService.class);
+        when(scriptService.isLangSupported(anyString())).thenReturn(true);
+        String propertyValue = randomAlphaOfLength(10);
+        ValueSource result = ValueSource.wrap(propertyValue, scriptService);
+        assertThat(result.copyAndResolve(null), equalTo(propertyValue));
+        verify(scriptService, times(0)).compile(any(), any());
+    }
+
+    public void testScriptShouldCompile() {
+        ScriptService scriptService = mock(ScriptService.class);
+        when(scriptService.isLangSupported(anyString())).thenReturn(true);
+        String propertyValue = "{{" + randomAlphaOfLength(10) + "}}";
+        String compiledValue = randomAlphaOfLength(10);
+        when(scriptService.compile(any(), any())).thenReturn(new TestTemplateService.MockTemplateScript.Factory(compiledValue));
+        ValueSource result = ValueSource.wrap(propertyValue, scriptService);
+        assertThat(result.copyAndResolve(Collections.emptyMap()), equalTo(compiledValue));
+        verify(scriptService, times(1)).compile(any(), any());
+    }
 }