KZL-1005 - Add method to use request context in SDK queries (#1245)

Adds a method to use the original request user inside the requests sent by the embedded SDK.
The main purpose of this feature is to properly set Kuzzle metadata (author and updater) on documents.

Call to sdk.as(user) method will instantiate a new SDK with a FunnelProcotol that takes the user in the constructor and inject it in the request context before passing the request to theFunnel.

// This will create a document with `author` metadata to `null`
this.context.accessors.sdk.document.create(...); 

// This will create a document with `author` metadata to the original request user
this.context.accessors.sdk.as(request.context.user).document.create(...);

// This will throw a PluginImplementationError, no user impersonation for now
this.context.accessors.sdk.as({ user: { _id: 'gordon' } }).document.create(...);
Documentation: kuzzleio/documentation#253

lib/api/core/plugins/pluginContext.js

@@ -24,6 +24,7 @@
 const
   Bluebird = require('bluebird'),
   _ = require('lodash'),
+  User = require('../models/security/user'),
   Koncorde = require('koncorde'),
   KuzzleSDK = require('kuzzle-sdk').Kuzzle,
   FunnelProtocol = require('../sdk/funnelProtocol'),
@@ -77,7 +78,7 @@ class PluginContext {
         // forbids uppercased characters in index names.
         internalEngineIndex = `%plugin:${pluginName}`.toLowerCase(),
         pluginInternalEngine = new InternalEngine(kuzzle, internalEngineIndex),
-        sdk = new KuzzleSDK(new FunnelProtocol(kuzzle.funnel));
+        kuzzleSdk = new KuzzleSDK(new FunnelProtocol(kuzzle.funnel));
 
       pluginInternalEngine.init(new PluginInternalEngineBootstrap(pluginName, kuzzle, pluginInternalEngine));
 
@@ -135,20 +136,40 @@ class PluginContext {
         get: () => curryTrigger(kuzzle, pluginName)
       });
 
+      const getPluginSdk = sdk => ({
+        query: sdk.query.bind(sdk),
+        auth: sdk.auth,
+        bulk: sdk.bulk,
+        collection: sdk.collection,
+        document: sdk.document,
+        index: sdk.index,
+        ms: sdk.ms,
+        realtime: new Proxy({}, {
+          get () {
+            throw new PluginImplementationError('Realtime controller is not available in plugins. You should use plugin hooks instead');
+          }
+        }),
+        security: sdk.security,
+        server: sdk.server
+      });
+
       Object.defineProperty(this.accessors, 'sdk', {
         enumerable: true,
-        get: () => ({
-          query: sdk.query.bind(sdk),
-          auth: sdk.auth,
-          bulk: sdk.bulk,
-          collection: sdk.collection,
-          document: sdk.document,
-          index: sdk.index,
-          ms: sdk.ms,
-          realtime: sdk.realtime,
-          security: sdk.security,
-          server: sdk.server
-        })
+        get: () => {
+          const pluginSdk = getPluginSdk(kuzzleSdk);
+
+          pluginSdk.as = user => {
+            if (!(user instanceof User)) {
+              throw new PluginImplementationError('You must provide a valid User object when adding context with as()');
+            }
+
+            return getPluginSdk(
+              new KuzzleSDK(new FunnelProtocol(kuzzle.funnel, user))
+            );
+          };
+
+          return pluginSdk;
+        }
       });
 
       /**

lib/api/core/sdk/funnelProtocol.js

@@ -22,23 +22,43 @@
 'use strict';
 
 const
-  KuzzleEventEmitter = require('kuzzle-sdk').KuzzleEventEmitter,
-  Request = require('kuzzle-common-objects').Request;
+  {
+    Request,
+    errors: {
+      InternalError: KuzzleInternalError
+    }
+  } = require('kuzzle-common-objects'),
+  User = require('../models/security/user'),
+  KuzzleEventEmitter = require('kuzzle-sdk').KuzzleEventEmitter;
 
 class FunnelProtocol extends KuzzleEventEmitter {
-  constructor(funnel) {
+  constructor(funnel, user = null) {
     super();
+
     this.funnel = funnel;
     this.id = 'funnel';
+    this.user = user;
+
+    if (this.user && !(this.user instanceof User)) {
+      throw new KuzzleInternalError(`FunnelProtocol.constructor: Invalid User object '${JSON.stringify(user)}'`);
+    }
   }
 
-  isReady() {
+  isReady () {
     return true;
   }
 
+  /**
+   *  Hydrate the user and execute SDK query
+   */
   query (request) {
-    return this.funnel.executePluginRequest(new Request(request))
-      .then(result => ({result}));
+    const kuzzleRequest = new Request(request, {
+      connection: { protocol: 'funnel' },
+      user: this.user
+    });
+
+    return this.funnel.executePluginRequest(kuzzleRequest)
+      .then(result => ({ result }));
   }
 }