Scripting: Add optional context parameter to put stored script requests (#25014)

This commit adds an optional `context` url parameter to the put stored
script request. When a context is specified, the script is compiled
against that context before storing, as a validation the script will
work when used in that context.

Author: rjernst

core/src/main/java/org/elasticsearch/action/admin/cluster/storedscripts/PutStoredScriptRequest.java

@@ -38,17 +38,19 @@ public class PutStoredScriptRequest extends AcknowledgedRequest<PutStoredScriptR
 
     private String id;
     private String lang;
+    private String context;
     private BytesReference content;
     private XContentType xContentType;
 
     public PutStoredScriptRequest() {
         super();
     }
 
-    public PutStoredScriptRequest(String id, String lang, BytesReference content, XContentType xContentType) {
+    public PutStoredScriptRequest(String id, String lang, String context, BytesReference content, XContentType xContentType) {
         super();
         this.id = id;
         this.lang = lang;
+        this.context = context;
         this.content = content;
         this.xContentType = Objects.requireNonNull(xContentType);
     }
@@ -94,6 +96,15 @@ public PutStoredScriptRequest lang(String lang) {
         return this;
     }
 
+    public String context() {
+        return context;
+    }
+
+    public PutStoredScriptRequest context(String context) {
+        this.context = context;
+        return this;
+    }
+
     public BytesReference content() {
         return content;
     }
@@ -128,6 +139,9 @@ public void readFrom(StreamInput in) throws IOException {
         } else {
             xContentType = XContentFactory.xContentType(content);
         }
+        if (in.getVersion().onOrAfter(Version.V_6_0_0_alpha2)) {
+            context = in.readOptionalString();
+        }
     }
 
     @Override
@@ -140,6 +154,9 @@ public void writeTo(StreamOutput out) throws IOException {
         if (out.getVersion().onOrAfter(Version.V_5_3_0)) {
             xContentType.writeTo(out);
         }
+        if (out.getVersion().onOrAfter(Version.V_6_0_0_alpha2)) {
+            out.writeOptionalString(context);
+        }
     }
 
     @Override

core/src/main/java/org/elasticsearch/rest/action/admin/cluster/RestPutStoredScriptAction.java

@@ -50,6 +50,7 @@ public RestPutStoredScriptAction(Settings settings, RestController controller) {
     public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client) throws IOException {
         String id = request.param("id");
         String lang = request.param("lang");
+        String context = request.param("context");
 
         // In the case where only {lang} is not null, we make it {id} because of
         // name ordering issues in the handlers' paths.
@@ -65,7 +66,7 @@ public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client
                 "specifying lang [" + lang + "] as part of the url path is deprecated, use request content instead");
         }
 
-        PutStoredScriptRequest putRequest = new PutStoredScriptRequest(id, lang, content, request.getXContentType());
+        PutStoredScriptRequest putRequest = new PutStoredScriptRequest(id, lang, context, content, request.getXContentType());
         return channel -> client.admin().cluster().putStoredScript(putRequest, new AcknowledgedRestListener<>(channel));
     }
 }

core/src/main/java/org/elasticsearch/script/ScriptService.java

@@ -431,14 +431,12 @@ public void putStoredScript(ClusterService clusterService, PutStoredScriptReques
             } else if (isAnyContextEnabled() == false) {
                 throw new IllegalArgumentException(
                     "cannot put [" + ScriptType.STORED + "] script, no script contexts are enabled");
-            } else {
-                // TODO: executable context here is just a placeholder, replace with optional context name passed into PUT stored script req
-                Object compiled = scriptEngine.compile(request.id(), source.getCode(), ExecutableScript.CONTEXT, Collections.emptyMap());
-
-                if (compiled == null) {
-                    throw new IllegalArgumentException("failed to parse/compile stored script [" + request.id() + "]" +
-                        (source.getCode() == null ? "" : " using code [" + source.getCode() + "]"));
+            } else if (request.context() != null) {
+                ScriptContext<?> context = contexts.get(request.context());
+                if (context == null) {
+                    throw new IllegalArgumentException("Unknown context [" + request.context() + "]");
                 }
+                scriptEngine.compile(request.id(), source.getCode(), context, Collections.emptyMap());
             }
         } catch (ScriptException good) {
             throw good;

core/src/test/java/org/elasticsearch/action/admin/cluster/storedscripts/PutStoredScriptRequestTests.java

@@ -32,7 +32,8 @@
 public class PutStoredScriptRequestTests extends ESTestCase {
 
     public void testSerialization() throws IOException {
-        PutStoredScriptRequest storedScriptRequest = new PutStoredScriptRequest("foo", "bar", new BytesArray("{}"), XContentType.JSON);
+        PutStoredScriptRequest storedScriptRequest =
+            new PutStoredScriptRequest("foo", "bar", "context", new BytesArray("{}"), XContentType.JSON);
 
         assertEquals(XContentType.JSON, storedScriptRequest.xContentType());
         try (BytesStreamOutput output = new BytesStreamOutput()) {
@@ -44,6 +45,7 @@ public void testSerialization() throws IOException {
                 assertEquals(XContentType.JSON, serialized.xContentType());
                 assertEquals(storedScriptRequest.lang(), serialized.lang());
                 assertEquals(storedScriptRequest.id(), serialized.id());
+                assertEquals(storedScriptRequest.context(), serialized.context());
             }
         }
     }

modules/lang-mustache/src/main/java/org/elasticsearch/script/mustache/RestPutSearchTemplateAction.java

@@ -26,6 +26,7 @@
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.rest.action.AcknowledgedRestListener;
+import org.elasticsearch.script.ExecutableScript;
 import org.elasticsearch.script.Script;
 
 import java.io.IOException;
@@ -47,7 +48,8 @@ public RestChannelConsumer prepareRequest(RestRequest request, NodeClient client
         String id = request.param("id");
         BytesReference content = request.content();
 
-        PutStoredScriptRequest put = new PutStoredScriptRequest(id, Script.DEFAULT_TEMPLATE_LANG, content, request.getXContentType());
+        PutStoredScriptRequest put = new PutStoredScriptRequest(id, Script.DEFAULT_TEMPLATE_LANG, ExecutableScript.CONTEXT.name,
+            content, request.getXContentType());
         return channel -> client.admin().cluster().putStoredScript(put, new AcknowledgedRestListener<>(channel));
     }
 }

modules/lang-painless/src/test/resources/rest-api-spec/test/painless/16_update2.yml

@@ -38,10 +38,12 @@
       catch: request
       put_script:
         id: "1"
+        context: "search"
         body: { "script": {"lang": "painless", "code": "_score * foo bar + doc['myParent.weight'].value"} }
 
   - do:
       catch: /compile error/
       put_script:
         id: "1"
+        context: "search"
         body: { "script": {"lang": "painless", "code": "_score * foo bar + doc['myParent.weight'].value"} }

rest-api-spec/src/main/resources/rest-api-spec/api/put_script.json

@@ -18,6 +18,10 @@
         }
       },
       "params" : {
+        "context": {
+          "type" : "string",
+          "description" : "Context name to compile script against"
+        }
       }
     },
     "body": {