Deguice rest handlers (#22575)

There are presently 7 ctor args used in any rest handlers:
* `Settings`: Every handler uses it to initialize a logger and
  some other strange things.
* `RestController`: Every handler registers itself with it.
* `ClusterSettings`: Used by `RestClusterGetSettingsAction` to
  render the default values for cluster settings.
* `IndexScopedSettings`: Used by `RestGetSettingsAction` to get
  the default values for index settings.
* `SettingsFilter`: Used by a few handlers to filter returned
  settings so we don't expose stuff like passwords.
* `IndexNameExpressionResolver`: Used by `_cat/indices` to
  filter the list of indices.
* `Supplier<DiscoveryNodes>`: Used to fill enrich the response
  by handlers that list tasks.

We probably want to reduce these arguments over time but
switching construction away from guice gives us tighter
control over the list of available arguments.

These parameters are passed to plugins using
`ActionPlugin#initRestHandlers` which is expected to build and
return that handlers immediately. This felt simpler than
returning an reference to the ctors given all the different
possible args.

Breaks java plugins by moving rest handlers off of guice.

7 files changed, 17 insertions, 18 deletions

diff --git a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MustachePlugin.java b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MustachePlugin.java
index a5a0ded3be..36f598a821 100644
--- a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MustachePlugin.java
+++ b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/MustachePlugin.java
@@ -21,16 +21,23 @@ package org.elasticsearch.script.mustache;
 
 import org.elasticsearch.action.ActionRequest;
 import org.elasticsearch.action.ActionResponse;
+import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
+import org.elasticsearch.cluster.node.DiscoveryNodes;
+import org.elasticsearch.common.settings.ClusterSettings;
+import org.elasticsearch.common.settings.IndexScopedSettings;
 import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.settings.SettingsFilter;
 import org.elasticsearch.plugins.ActionPlugin;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.plugins.ScriptPlugin;
 import org.elasticsearch.plugins.SearchPlugin;
+import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestHandler;
 import org.elasticsearch.script.ScriptEngineService;
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.function.Supplier;
 
 import static java.util.Collections.singletonList;
 
@@ -53,8 +60,15 @@ public class MustachePlugin extends Plugin implements ScriptPlugin, ActionPlugin
     }
 
     @Override
-    public List<Class<? extends RestHandler>> getRestHandlers() {
-        return Arrays.asList(RestSearchTemplateAction.class, RestMultiSearchTemplateAction.class, RestGetSearchTemplateAction.class,
-                RestPutSearchTemplateAction.class, RestDeleteSearchTemplateAction.class, RestRenderSearchTemplateAction.class);
+    public List<RestHandler> getRestHandlers(Settings settings, RestController restController, ClusterSettings clusterSettings,
+            IndexScopedSettings indexScopedSettings, SettingsFilter settingsFilter, IndexNameExpressionResolver indexNameExpressionResolver,
+            Supplier<DiscoveryNodes> nodesInCluster) {
+        return Arrays.asList(
+                new RestSearchTemplateAction(settings, restController),
+                new RestMultiSearchTemplateAction(settings, restController),
+                new RestGetSearchTemplateAction(settings, restController),
+                new RestPutSearchTemplateAction(settings, restController),
+                new RestDeleteSearchTemplateAction(settings, restController),
+                new RestRenderSearchTemplateAction(settings, restController));
     }
 }
diff --git a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestDeleteSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestDeleteSearchTemplateAction.java
index a6ea92e281..027235496b 100644
--- a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestDeleteSearchTemplateAction.java
+++ b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestDeleteSearchTemplateAction.java
@@ -18,7 +18,6 @@
  */
 package org.elasticsearch.script.mustache;
 
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
@@ -27,8 +26,6 @@ import org.elasticsearch.rest.action.admin.cluster.RestDeleteStoredScriptAction;
 import static org.elasticsearch.rest.RestRequest.Method.DELETE;
 
 public class RestDeleteSearchTemplateAction extends RestDeleteStoredScriptAction {
-
-    @Inject
     public RestDeleteSearchTemplateAction(Settings settings, RestController controller) {
         super(settings, controller, false);
         controller.registerHandler(DELETE, "/_search/template/{id}", this);
diff --git a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestGetSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestGetSearchTemplateAction.java
index 16ab14bc6c..c02c01273a 100644
--- a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestGetSearchTemplateAction.java
+++ b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestGetSearchTemplateAction.java
@@ -18,7 +18,6 @@
  */
 package org.elasticsearch.script.mustache;
 
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
@@ -30,7 +29,6 @@ public class RestGetSearchTemplateAction extends RestGetStoredScriptAction {
 
     private static final String TEMPLATE = "template";
 
-    @Inject
     public RestGetSearchTemplateAction(Settings settings, RestController controller) {
         super(settings, controller, false);
         controller.registerHandler(GET, "/_search/template/{id}", this);
diff --git a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestMultiSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestMultiSearchTemplateAction.java
index ecaa360bc4..6b0497e53f 100644
--- a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestMultiSearchTemplateAction.java
+++ b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestMultiSearchTemplateAction.java
@@ -22,7 +22,6 @@ package org.elasticsearch.script.mustache;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestController;
@@ -39,7 +38,6 @@ public class RestMultiSearchTemplateAction extends BaseRestHandler {
 
     private final boolean allowExplicitIndex;
 
-    @Inject
     public RestMultiSearchTemplateAction(Settings settings, RestController controller) {
         super(settings);
         this.allowExplicitIndex = MULTI_ALLOW_EXPLICIT_INDEX.get(settings);
diff --git a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestPutSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestPutSearchTemplateAction.java
index 718afb608e..2426a09ec8 100644
--- a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestPutSearchTemplateAction.java
+++ b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestPutSearchTemplateAction.java
@@ -18,7 +18,6 @@
  */
 package org.elasticsearch.script.mustache;
 
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
@@ -28,8 +27,6 @@ import static org.elasticsearch.rest.RestRequest.Method.POST;
 import static org.elasticsearch.rest.RestRequest.Method.PUT;
 
 public class RestPutSearchTemplateAction extends RestPutStoredScriptAction {
-
-    @Inject
     public RestPutSearchTemplateAction(Settings settings, RestController controller) {
         super(settings, controller, false);
         controller.registerHandler(POST, "/_search/template/{id}", this);
diff --git a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestRenderSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestRenderSearchTemplateAction.java
index 482b2a13c8..6647bd4bd4 100644
--- a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestRenderSearchTemplateAction.java
+++ b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestRenderSearchTemplateAction.java
@@ -20,7 +20,6 @@
 package org.elasticsearch.script.mustache;
 
 import org.elasticsearch.client.node.NodeClient;
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.rest.BaseRestHandler;
@@ -35,8 +34,6 @@ import static org.elasticsearch.rest.RestRequest.Method.GET;
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
 public class RestRenderSearchTemplateAction extends BaseRestHandler {
-
-    @Inject
     public RestRenderSearchTemplateAction(Settings settings, RestController controller) {
         super(settings);
         controller.registerHandler(GET, "/_render/template", this);
diff --git a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestSearchTemplateAction.java b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestSearchTemplateAction.java
index 32f6ad6f36..bb263dd5a2 100644
--- a/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestSearchTemplateAction.java
+++ b/modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestSearchTemplateAction.java
@@ -24,7 +24,6 @@ import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.client.node.NodeClient;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParsingException;
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -74,7 +73,6 @@ public class RestSearchTemplateAction extends BaseRestHandler {
         }, new ParseField("inline", "template"), ObjectParser.ValueType.OBJECT_OR_STRING);
     }
 
-    @Inject
     public RestSearchTemplateAction(Settings settings, RestController controller) {
         super(settings);