Add deprecation check for pidfile setting (#45939)

The pidfile setting is deprecated. This commit adds a deprecation check
for usage of this setting.

x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/DeprecationChecks.java

@@ -41,6 +41,7 @@ public class DeprecationChecks {
 
     static List<BiFunction<Settings, PluginsAndModules, DeprecationIssue>> NODE_SETTINGS_CHECKS =
         Collections.unmodifiableList(Arrays.asList(
+            NodeDeprecationChecks::checkPidfile,
             NodeDeprecationChecks::checkProcessors
         ));
 

x-pack/plugin/deprecation/src/main/java/org/elasticsearch/xpack/deprecation/NodeDeprecationChecks.java

@@ -7,32 +7,59 @@
 package org.elasticsearch.xpack.deprecation;
 
 import org.elasticsearch.action.admin.cluster.node.info.PluginsAndModules;
+import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.concurrent.EsExecutors;
+import org.elasticsearch.env.Environment;
 import org.elasticsearch.xpack.core.deprecation.DeprecationIssue;
 
 import java.util.Locale;
 
 class NodeDeprecationChecks {
 
+    static DeprecationIssue checkPidfile(final Settings settings, final PluginsAndModules pluginsAndModules) {
+        return checkDeprecatedSetting(
+            settings,
+            pluginsAndModules,
+            Environment.PIDFILE_SETTING,
+            Environment.NODE_PIDFILE_SETTING,
+            "https://www.elastic.co/guide/en/elasticsearch/reference/7.4/breaking-changes-7.4.html#deprecate-pidfile");
+    }
+
     static DeprecationIssue checkProcessors(final Settings settings , final PluginsAndModules pluginsAndModules) {
-        if (EsExecutors.PROCESSORS_SETTING.exists(settings) == false) {
+        return checkDeprecatedSetting(
+            settings,
+            pluginsAndModules,
+            EsExecutors.PROCESSORS_SETTING,
+            EsExecutors.NODE_PROCESSORS_SETTING,
+            "https://www.elastic.co/guide/en/elasticsearch/reference/7.4/breaking-changes-7.4.html#deprecate-processors");
+    }
+
+    private static DeprecationIssue checkDeprecatedSetting(
+        final Settings settings,
+        final PluginsAndModules pluginsAndModules,
+        final Setting<?> deprecatedSetting,
+        final Setting<?> replacementSetting,
+        final String url) {
+        assert deprecatedSetting.isDeprecated() : deprecatedSetting;
+        if (deprecatedSetting.exists(settings) == false) {
             return null;
         }
+        final String deprecatedSettingKey = deprecatedSetting.getKey();
+        final String replacementSettingKey = replacementSetting.getKey();
+        final String value = deprecatedSetting.get(settings).toString();
         final String message = String.format(
             Locale.ROOT,
             "setting [%s] is deprecated in favor of setting [%s]",
-            EsExecutors.PROCESSORS_SETTING.getKey(),
+            deprecatedSettingKey,
-            EsExecutors.NODE_PROCESSORS_SETTING.getKey());
+            replacementSettingKey);
-        final String url =
-            "https://www.elastic.co/guide/en/elasticsearch/reference/7.4/breaking-changes-7.4.html#deprecate-processors";
         final String details = String.format(
             Locale.ROOT,
-            "the setting [%s] is currently set to [%d], instead set [%s] to [%d]",
+            "the setting [%s] is currently set to [%s], instead set [%s] to [%s]",
-            EsExecutors.PROCESSORS_SETTING.getKey(),
+            deprecatedSettingKey,
-            EsExecutors.PROCESSORS_SETTING.get(settings),
+            value,
-            EsExecutors.NODE_PROCESSORS_SETTING.getKey(),
+            replacementSettingKey,
-            EsExecutors.PROCESSORS_SETTING.get(settings));
+            value);
         return new DeprecationIssue(DeprecationIssue.Level.CRITICAL, message, url, details);
     }
 

x-pack/plugin/deprecation/src/test/java/org/elasticsearch/xpack/deprecation/NodeDeprecationChecksTests.java

@@ -10,6 +10,7 @@ import org.elasticsearch.action.admin.cluster.node.info.PluginsAndModules;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.concurrent.EsExecutors;
+import org.elasticsearch.env.Environment;
 import org.elasticsearch.test.ESTestCase;
 import org.elasticsearch.xpack.core.deprecation.DeprecationIssue;
 
@@ -21,6 +22,29 @@ import static org.hamcrest.Matchers.empty;
 
 public class NodeDeprecationChecksTests extends ESTestCase {
 
+    public void testCheckDefaults() {
+        final Settings settings = Settings.EMPTY;
+        final PluginsAndModules pluginsAndModules = new PluginsAndModules(Collections.emptyList(), Collections.emptyList());
+        final List<DeprecationIssue> issues =
+            DeprecationChecks.filterChecks(DeprecationChecks.NODE_SETTINGS_CHECKS, c -> c.apply(settings, pluginsAndModules));
+        assertThat(issues, empty());
+    }
+
+    public void testCheckPidfile() {
+        final String pidfile = randomAlphaOfLength(16);
+        final Settings settings = Settings.builder().put(Environment.PIDFILE_SETTING.getKey(), pidfile).build();
+        final PluginsAndModules pluginsAndModules = new PluginsAndModules(Collections.emptyList(), Collections.emptyList());
+        final List<DeprecationIssue> issues =
+            DeprecationChecks.filterChecks(DeprecationChecks.NODE_SETTINGS_CHECKS, c -> c.apply(settings, pluginsAndModules));
+        final DeprecationIssue expected = new DeprecationIssue(
+            DeprecationIssue.Level.CRITICAL,
+            "setting [pidfile] is deprecated in favor of setting [node.pidfile]",
+            "https://www.elastic.co/guide/en/elasticsearch/reference/7.4/breaking-changes-7.4.html#deprecate-pidfile",
+            "the setting [pidfile] is currently set to [" + pidfile + "], instead set [node.pidfile] to [" + pidfile + "]");
+        assertThat(issues, contains(expected));
+        assertSettingDeprecationsAndWarnings(new Setting<?>[]{Environment.PIDFILE_SETTING});
+    }
+
     public void testCheckProcessors() {
         final int processors = randomIntBetween(1, 4);
         final Settings settings = Settings.builder().put(EsExecutors.PROCESSORS_SETTING.getKey(), processors).build();
@@ -36,12 +60,4 @@ public class NodeDeprecationChecksTests extends ESTestCase {
         assertSettingDeprecationsAndWarnings(new Setting<?>[]{EsExecutors.PROCESSORS_SETTING});
     }
 
-    public void testCheckProcessorsNotSet() {
-        final Settings settings = Settings.EMPTY;
-        final PluginsAndModules pluginsAndModules = new PluginsAndModules(Collections.emptyList(), Collections.emptyList());
-        final List<DeprecationIssue> issues =
-            DeprecationChecks.filterChecks(DeprecationChecks.NODE_SETTINGS_CHECKS, c -> c.apply(settings, pluginsAndModules));
-        assertThat(issues, empty());
-    }
-
 }