Merge pull request #245 from ascrutae/zhangxin/feature/force-enable-plugin

Add mechanism to set default status(on/off) of plugin

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/conf/Config.java

@@ -101,6 +101,12 @@ public class Config {
          */
         public static List DISABLED_PLUGINS = new LinkedList();
 
+        /**
+         * Name of force enable plugin, The value spilt by <code>,</code>
+         * if you have multiple plugins need to enable.
+         */
+        public static List FORCE_ENABLE_PLUGINS = new LinkedList();
+
         public static class MongoDB {
             /**
              * If true, trace all the parameters, default is false.

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/plugin/PluginDefine.java

@@ -5,6 +5,7 @@ import org.skywalking.apm.agent.core.plugin.exception.IllegalPluginDefineExcepti
 import org.skywalking.apm.util.StringUtil;
 
 public class PluginDefine {
+    public static final String PLUGIN_OFF_PREFIX = "[OFF]";
     /**
      * Plugin name.
      */
@@ -15,9 +16,15 @@ public class PluginDefine {
      */
     private String defineClass;
 
-    private PluginDefine(String name, String defineClass) {
+    /**
+     * The sate of plugin.
+     */
+    private State state;
+
+    private PluginDefine(String name, String defineClass, State state) {
         this.name = name;
         this.defineClass = defineClass;
+        this.state = state;
     }
 
     public static PluginDefine build(String define) throws IllegalPluginDefineException {
@@ -30,16 +37,34 @@ public class PluginDefine {
             throw new IllegalPluginDefineException(define);
         }
 
-        return new PluginDefine(pluginDefine[0], pluginDefine[1]);
+        String pluginName = pluginDefine[0];
+        String defineClass = pluginDefine[1];
+        if (pluginName.toUpperCase().startsWith(PLUGIN_OFF_PREFIX)) {
+            return new PluginDefine(pluginName.substring(PLUGIN_OFF_PREFIX.length()), defineClass, State.OFF);
+        } else {
+            return new PluginDefine(pluginName, defineClass, State.ON);
+        }
     }
 
     public boolean enable() {
-        return !Config.Plugin.DISABLED_PLUGINS.contains(name);
+        return !forceDisable() || forceEnable();
+    }
+
+    private boolean forceDisable() {
+        return state != State.ON || Config.Plugin.DISABLED_PLUGINS.contains(name);
+    }
+
+    private boolean forceEnable() {
+        return state == State.OFF && Config.Plugin.FORCE_ENABLE_PLUGINS.contains(name);
     }
 
     public String getDefineClass() {
         return defineClass;
     }
+
+    private enum State {
+        OFF, ON;
+    }
 }
 
 

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/plugin/PluginDefineTest.java

+package org.skywalking.apm.agent.core.plugin;
+
+import org.junit.Test;
+import org.skywalking.apm.agent.core.conf.Config;
+import org.skywalking.apm.agent.core.plugin.exception.IllegalPluginDefineException;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class PluginDefineTest {
+
+    private static final String TEST_PLUGIN = "test_plugin";
+    private static final String TEST_DEFINE_CLASS = "test_define_class";
+
+    @Test(expected = IllegalPluginDefineException.class)
+    public void testIllegalPluginDefine() throws IllegalPluginDefineException {
+        PluginDefine.build("illegal_plugin_define");
+    }
+
+    @Test(expected = IllegalPluginDefineException.class)
+    public void testEmptyPluginDefine() throws IllegalPluginDefineException {
+        PluginDefine.build("");
+    }
+
+    @Test
+    public void testOffStatePlugin() throws IllegalPluginDefineException {
+        PluginDefine pluginDefine = PluginDefine.build(PluginDefine.PLUGIN_OFF_PREFIX + TEST_PLUGIN + "=" + TEST_DEFINE_CLASS);
+        assertFalse(pluginDefine.enable());
+        assertEquals(TEST_DEFINE_CLASS, pluginDefine.getDefineClass());
+    }
+
+    @Test
+    public void testDefaultStatePlugin() throws IllegalPluginDefineException {
+        PluginDefine pluginDefine = PluginDefine.build(TEST_PLUGIN + "=" + TEST_DEFINE_CLASS);
+        assertTrue(pluginDefine.enable());
+        assertEquals(TEST_DEFINE_CLASS, pluginDefine.getDefineClass());
+    }
+
+    @Test
+    public void testForceEnablePlugin() throws IllegalPluginDefineException {
+        Config.Plugin.FORCE_ENABLE_PLUGINS.add(TEST_PLUGIN);
+        PluginDefine pluginDefine = PluginDefine.build(PluginDefine.PLUGIN_OFF_PREFIX + TEST_PLUGIN + "=" + TEST_DEFINE_CLASS);
+        assertTrue(pluginDefine.enable());
+        assertEquals(TEST_DEFINE_CLASS, pluginDefine.getDefineClass());
+        Config.Plugin.FORCE_ENABLE_PLUGINS.clear();
+    }
+}