Backport PR #8283

---------

**Commit 1:**
fixes plugin path in .gitignore

* Original sha: f74eb9b4cb
* Authored by Jim Unger <bigfunger@gmail.com> on 2016-09-14T18:40:21Z

**Commit 2:**
Moves version from plugin installer to utils

* Original sha: ae492ff066
* Authored by Jim Unger <bigfunger@gmail.com> on 2016-09-14T18:41:19Z

**Commit 3:**
Adds plugin version check to kibana startup

* Original sha: 83d0821054
* Authored by Jim Unger <bigfunger@gmail.com> on 2016-09-14T18:41:40Z

**Commit 4:**
Changes plugin version to 'kibana' in text fixture

* Original sha: 922c04abe6
* Authored by Jim Unger <bigfunger@gmail.com> on 2016-09-14T19:07:09Z

**Commit 5:**
Merge branch 'master' into check-plugin-version-on-startup

* Original sha: 5da33adfdb
* Authored by Jim Unger <bigfunger@gmail.com> on 2016-09-15T14:45:01Z

**Commit 6:**
review changes to check_version

* Original sha: 2802410573
* Authored by Jim Unger <bigfunger@gmail.com> on 2016-09-15T16:53:28Z

**Commit 7:**
reworked logic to remove config when deleting a plugin from plugin_collection

* Original sha: 2f52be62ae
* Authored by Jim Unger <bigfunger@gmail.com> on 2016-09-15T20:11:43Z

**Commit 8:**
Adds a kibanaVersion property to the Plugin class

* Original sha: e920bca051
* Authored by Jim Unger <bigfunger@gmail.com> on 2016-09-15T21:04:41Z

**Commit 9:**
move enabled check into it's own mixin, and cleaned up how you disable a plugin

* Original sha: 049c029764
* Authored by Jim Unger <bigfunger@gmail.com> on 2016-09-16T17:22:47Z

.gitignore

@@ -21,7 +21,7 @@ target
 /esvm
 .htpasswd
 .eslintcache
-plugins
+/plugins/
 data
 disabledPlugins
 webpackstats.json

src/cli_plugin/install/kibana.js

@@ -2,7 +2,7 @@ import _ from 'lodash';
 import { fromRoot } from '../../utils';
 import KbnServer from '../../server/kbn_server';
 import readYamlConfig from '../../cli/serve/read_yaml_config';
-import { versionSatisfies, cleanVersion } from './version';
+import { versionSatisfies, cleanVersion } from '../../utils/version';
 import { statSync } from 'fs';
 
 export function existingInstall(settings, logger) {

src/server/kbn_server.js

@@ -28,6 +28,12 @@ module.exports = class KbnServer {
       // find plugins and set this.plugins
       require('./plugins/scan'),
 
+      // disable the plugins that are disabled through configuration
+      require('./plugins/check_enabled'),
+
+      // disable the plugins that are incompatible with the current version of Kibana
+      require('./plugins/check_version'),
+
       // tell the config we are done loading plugins
       require('./config/complete'),
 

src/server/plugins/check_enabled.js

@@ -0,0 +1,15 @@
+import toPath from 'lodash/internal/toPath';
+
+export default async function (kbnServer, server, config) {
+  const { plugins } = kbnServer;
+
+  for (let plugin of plugins) {
+    const enabledInConfig = config.get([...toPath(plugin.configPrefix), 'enabled']);
+
+    if (!enabledInConfig) {
+      plugins.disable(plugin);
+    }
+  }
+
+  return;
+};

src/server/plugins/check_version.js

@@ -0,0 +1,36 @@
+import { cleanVersion, versionSatisfies } from '../../utils/version';
+import { get } from 'lodash';
+
+function compatibleWithKibana(kbnServer, plugin) {
+  //core plugins have a version of 'kibana' and are always compatible
+  if (plugin.kibanaVersion === 'kibana') return true;
+
+  const pluginKibanaVersion = cleanVersion(plugin.kibanaVersion);
+  const kibanaVersion = cleanVersion(kbnServer.version);
+
+  return versionSatisfies(pluginKibanaVersion, kibanaVersion);
+}
+
+export default async function (kbnServer, server, config) {
+  //because a plugin pack can contain more than one actual plugin, (for example x-pack)
+  //we make sure that the warning messages are unique
+  const warningMessages = new Set();
+  const plugins = kbnServer.plugins;
+
+  for (let plugin of plugins) {
+    const version = plugin.kibanaVersion;
+    const name = get(plugin, 'pkg.name');
+
+    if (!compatibleWithKibana(kbnServer, plugin)) {
+      const message = `Plugin "${name}" was disabled because it expected Kibana version "${version}", and found "${kbnServer.version}".`;
+      warningMessages.add(message);
+      plugins.disable(plugin);
+    }
+  }
+
+  for (let message of warningMessages) {
+    server.log(['warning'], message);
+  }
+
+  return;
+};

src/server/plugins/plugin.js

@@ -1,5 +1,4 @@
 import _ from 'lodash';
-import toPath from 'lodash/internal/toPath';
 import Joi from 'joi';
 import Bluebird, { attempt, fromNode } from 'bluebird';
 import { basename, resolve } from 'path';
@@ -59,10 +58,16 @@ module.exports = class Plugin {
     this.uiExportsSpecs = opts.uiExports || {};
     this.requiredIds = opts.require || [];
     this.version = opts.version || pkg.version;
+
+    // Plugins must specify their version, and by default that version should match
+    // the version of kibana down to the patch level. If these two versions need
+    // to diverge, they can specify a kibana.version in the package to indicate the
+    // version of kibana the plugin is intended to work with.
+    this.kibanaVersion = opts.kibanaVersion || _.get(pkg, 'kibana.version', this.version);
     this.externalPreInit = opts.preInit || _.noop;
     this.externalInit = opts.init || _.noop;
     this.configPrefix = opts.configPrefix || this.id;
-    this.getConfigSchema = opts.config || _.noop;
+    this.getExternalConfigSchema = opts.config || _.noop;
     this.preInit = _.once(this.preInit);
     this.init = _.once(this.init);
     this[extendInitFns] = [];
@@ -89,17 +94,9 @@ module.exports = class Plugin {
     };
   }
 
-  async readConfig() {
-    let schema = await this.getConfigSchema(Joi);
-    let { config } = this.kbnServer;
-    config.extendSchema(this.configPrefix, schema || defaultConfigSchema);
-
-    if (config.get([...toPath(this.configPrefix), 'enabled'])) {
-      return true;
-    } else {
-      config.removeSchema(this.configPrefix);
-      return false;
-    }
+  async getConfigSchema() {
+    let schema = await this.getExternalConfigSchema(Joi);
+    return schema || defaultConfigSchema;
   }
 
   async preInit() {

src/server/plugins/plugin_collection.js

@@ -2,11 +2,23 @@
 import PluginApi from './plugin_api';
 import { inspect } from 'util';
 import { get, indexBy } from 'lodash';
+import toPath from 'lodash/internal/toPath';
 import Collection from '../../utils/collection';
 
 let byIdCache = Symbol('byIdCache');
 let pluginApis = Symbol('pluginApis');
 
+async function addPluginConfig(pluginCollection, plugin) {
+  const configSchema = await plugin.getConfigSchema();
+  let { config } = pluginCollection.kbnServer;
+  config.extendSchema(plugin.configPrefix, configSchema);
+}
+
+function removePluginConfig(pluginCollection, plugin) {
+  let { config } = pluginCollection.kbnServer;
+  config.removeSchema(plugin.configPrefix);
+}
+
 module.exports = class Plugins extends Collection {
 
   constructor(kbnServer) {
@@ -27,21 +39,21 @@ module.exports = class Plugins extends Collection {
     // clear the byIdCache
     this[byIdCache] = null;
 
-    for (let product of output) {
-
-      if (product instanceof api.Plugin) {
-        let plugin = product;
-        this.add(plugin);
-
-        let enabled = await plugin.readConfig();
-        if (!enabled) this.delete(plugin);
-        continue;
+    for (let plugin of output) {
+      if (!plugin instanceof api.Plugin) {
+        throw new TypeError('unexpected plugin export ' + inspect(plugin));
       }
 
-      throw new TypeError('unexpected plugin export ' + inspect(product));
+      await addPluginConfig(this, plugin);
+      this.add(plugin);
     }
   }
 
+  async disable(plugin) {
+    removePluginConfig(this, plugin);
+    this.delete(plugin);
+  }
+
   get byId() {
     return this[byIdCache] || (this[byIdCache] = indexBy([...this], 'id'));
   }

src/ui/__tests__/fixtures/plugin_async_foo/package.json

@@ -1,4 +1,4 @@
 {
   "name": "plugin_async_foo",
-  "version": "0.0.0"
+  "version": "kibana"
 }

src/ui/__tests__/fixtures/plugin_bar/package.json

@@ -1,4 +1,4 @@
 {
   "name": "plugin_bar",
-  "version": "0.0.0"
+  "version": "kibana"
 }

src/ui/__tests__/fixtures/plugin_foo/package.json

@@ -1,4 +1,4 @@
 {
   "name": "plugin_foo",
-  "version": "0.0.0"
+  "version": "kibana"
 }