From cc766d2260a6562fac802e555f14962b93682754 Mon Sep 17 00:00:00 2001
From: Matteo Pagliazzi <matteopagliazzi@gmail.com>
Date: Wed, 27 Feb 2019 18:47:33 +0100
Subject: [PATCH] gcp stackdriver tracing: attach user id (#11033)

---
 website/server/index.js              |  8 +++-----
 website/server/libs/gcpTraceAgent.js | 12 ++++++++++++
 website/server/middlewares/auth.js   | 12 +++++++++++-
 3 files changed, 26 insertions(+), 6 deletions(-)
 create mode 100644 website/server/libs/gcpTraceAgent.js

diff --git a/website/server/index.js b/website/server/index.js
index 1662b33010..c1d6757dee 100644
--- a/website/server/index.js
+++ b/website/server/index.js
@@ -12,15 +12,13 @@ const setupNconf = require('./libs/setupNconf');
 setupNconf();
 const nconf = require('nconf');
 
-const IS_PROD = nconf.get('IS_PROD');
-const STACKDRIVER_TRACING_ENABLED = nconf.get('ENABLE_STACKDRIVER_TRACING') === 'true';
-if (IS_PROD && STACKDRIVER_TRACING_ENABLED) {
-  require('@google-cloud/trace-agent').start(); // eslint-disable-line global-require
-}
+// Initialize @google-cloud/trace-agent
+require('./libs/gcpTraceAgent');
 
 const cluster = require('cluster');
 const logger = require('./libs/logger');
 
+const IS_PROD = nconf.get('IS_PROD');
 const IS_DEV = nconf.get('IS_DEV');
 const CORES = Number(nconf.get('WEB_CONCURRENCY')) || 0;
 
diff --git a/website/server/libs/gcpTraceAgent.js b/website/server/libs/gcpTraceAgent.js
new file mode 100644
index 0000000000..0e017aa943
--- /dev/null
+++ b/website/server/libs/gcpTraceAgent.js
@@ -0,0 +1,12 @@
+const nconf = require('nconf');
+
+const IS_PROD = nconf.get('IS_PROD');
+const STACKDRIVER_TRACING_ENABLED = nconf.get('ENABLE_STACKDRIVER_TRACING') === 'true';
+
+let tracer = null;
+
+if (IS_PROD && STACKDRIVER_TRACING_ENABLED) {
+  tracer = require('@google-cloud/trace-agent').start(); // eslint-disable-line global-require
+}
+
+export default tracer;
\ No newline at end of file
diff --git a/website/server/middlewares/auth.js b/website/server/middlewares/auth.js
index ab5987b50e..f4c301acf9 100644
--- a/website/server/middlewares/auth.js
+++ b/website/server/middlewares/auth.js
@@ -6,6 +6,7 @@ import {
 } from '../models/user';
 import nconf from 'nconf';
 import url from 'url';
+import gcpStackdriverTracer from '../libs/gcpTraceAgent';
 
 const COMMUNITY_MANAGER_EMAIL = nconf.get('EMAILS_COMMUNITY_MANAGER_EMAIL');
 
@@ -34,6 +35,13 @@ function getUserFields (options, req) {
   return `notifications ${userFieldOptions.join(' ')}`;
 }
 
+// Make sure stackdriver traces are storing the user id
+function stackdriverTraceUserId (userId) {
+  if (gcpStackdriverTracer) {
+    gcpStackdriverTracer.getCurrentRootSpan().addLabel('userId', userId);
+  }
+}
+
 // Strins won't be translated here because getUserLanguage has not run yet
 
 // Authenticate a request through the x-api-user and x-api key header
@@ -64,8 +72,9 @@ export function authWithHeaders (options = {}) {
         if (user.auth.blocked) throw new NotAuthorized(res.t('accountSuspended', {communityManagerEmail: COMMUNITY_MANAGER_EMAIL, userId: user._id}));
 
         res.locals.user = user;
-
         req.session.userId = user._id;
+        stackdriverTraceUserId(user._id);
+
         return next();
       })
       .catch(next);
@@ -93,6 +102,7 @@ export function authWithSession (req, res, next) {
       if (!user) throw new NotAuthorized(res.t('invalidCredentials'));
 
       res.locals.user = user;
+      stackdriverTraceUserId(user._id);
       return next();
     })
     .catch(next);