Nashorn powered Javascript Script rule for filtering requests

Author: sscarduzio

src/main/java/org/elasticsearch/plugin/readonlyrest/acl/blocks/Block.java

@@ -10,6 +10,7 @@
 import org.elasticsearch.plugin.readonlyrest.acl.blocks.rules.RuleNotConfiguredException;
 import org.elasticsearch.plugin.readonlyrest.acl.blocks.rules.RuleExitResult;
 
+import javax.script.ScriptEngine;
 import java.util.Set;
 
 /**
@@ -71,6 +72,9 @@ public Block(Settings s, ESLogger logger) {
     try {
       conditionsToCheck.add(new ActionsRule(s));
     } catch (RuleNotConfiguredException e) {
+    } try {
+      conditionsToCheck.add(new ScriptRule(s));
+    } catch (RuleNotConfiguredException e) {
     }
   }
 
@@ -106,7 +110,6 @@ public static String valuesString() {
 
   public BlockExitResult check(RequestContext rc) {
     boolean match = true;
-
     for (Rule condition : conditionsToCheck) {
       // Exit at the first rule that matches the request
       RuleExitResult condExitResult = condition.match(rc);

src/main/java/org/elasticsearch/plugin/readonlyrest/acl/blocks/rules/impl/ScriptRule.java

@@ -0,0 +1,69 @@
+package org.elasticsearch.plugin.readonlyrest.acl.blocks.rules.impl;
+
+import jdk.nashorn.api.scripting.ScriptObjectMirror;
+import org.elasticsearch.common.Strings;
+import org.elasticsearch.common.logging.ESLogger;
+import org.elasticsearch.common.logging.Loggers;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.plugin.readonlyrest.acl.RequestContext;
+import org.elasticsearch.plugin.readonlyrest.acl.blocks.rules.Rule;
+import org.elasticsearch.plugin.readonlyrest.acl.blocks.rules.RuleExitResult;
+import org.elasticsearch.plugin.readonlyrest.acl.blocks.rules.RuleNotConfiguredException;
+
+import javax.script.Invocable;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+
+/**
+ * Created by sscarduzio on 14/02/2016.
+ */
+public class ScriptRule extends Rule {
+
+  private final static ESLogger logger = Loggers.getLogger(ScriptRule.class);
+
+  private Invocable inv = null;
+
+  public ScriptRule(Settings s) throws RuleNotConfiguredException {
+    super(s);
+    String source = s.get(KEY);
+    if(Strings.isNullOrEmpty(source)) {
+      throw new RuleNotConfiguredException();
+    }
+    ScriptEngineManager manager = new ScriptEngineManager();
+    ScriptEngine engine = manager.getEngineByName("nashorn");
+    try {
+      // parse code
+      ScriptObjectMirror som = (ScriptObjectMirror) engine.eval(source);
+      if(!som.isFunction()) {
+        logger.error("the javascript snippet should be a function. Found: " + source);
+        throw new RuleNotConfiguredException();
+      }
+      logger.info("Parsed script source: " + source + " " + som.isFunction() );
+      inv = (Invocable) engine;
+    } catch (ScriptException e) {
+      e.printStackTrace();
+      throw new RuleNotConfiguredException();
+    }
+  }
+
+  @Override
+  public RuleExitResult match(RequestContext rc) {
+    String cause = "script returned false";
+    try {
+      // call function from script file
+      Boolean result = (Boolean) inv.invokeFunction("onRequest", rc);
+      if (result) {
+        return MATCH;
+      }
+    } catch (ScriptException e) {
+      e.printStackTrace();
+      cause = e.getMessage();
+    } catch (NoSuchMethodException e) {
+      e.printStackTrace();
+      cause = e.getMessage();
+    }
+    logger.debug("OnRequest script did not match. Cause: " + cause);
+    return NO_MATCH;
+  }
+}