A better URL for checking the deployed version (#2366)

README.md

@@ -242,6 +242,31 @@ Example: Building and running a production instance of the admin app:
 NODE_APP_INSTANCE=admin NODE_ENV=production npm run build && npm run start
 ```
 
+## What version is deployed?
+
+You can check to see what commit of `addons-frontend` is deployed by
+making a request like this:
+
+````
+curl https://addons-dev.allizom.org/__frontend_version__
+{
+   "build" : "https://circleci.com/gh/mozilla/addons-server/6550",
+   "commit" : "87f49a40ee7a5e87d9b9efde8e91b9019e8b13d1",
+   "source" : "https://github.com/mozilla/addons-server",
+   "version" : ""
+}
+````
+
+This will return a 415 response if a `version.json` file doesn't exist
+in the root directory. This file is typically generated by the deploy process.
+
+For consistency with monitoring scripts, the same data can be retrieved
+at this URL:
+
+````
+curl https://addons-dev.allizom.org/__version__
+````
+
 ## Overview and rationale
 
 This project will hold distinct front-ends e.g:

config/default-amo.js

@@ -46,6 +46,7 @@ module.exports = {
     'blocklist',
     'static',
     'user-media',
+    '__frontend_version__',
     '__version__',
   ],
 
@@ -76,6 +77,7 @@ module.exports = {
     'sunbird',
     'static',
     'user-media',
+    '__frontend_version__',
     '__version__',
   ],
   // These URLs are exceptions to our trailing slash URL redirects; if we

src/core/server/base.js

@@ -37,6 +37,7 @@ import WebpackIsomorphicToolsConfig from './webpack-isomorphic-tools-config';
 
 
 const env = config.util.getEnv('NODE_ENV');
+// This is a magic file that gets written by deployment scripts.
 const version = path.join(config.get('basePath'), 'version.json');
 const isDeployed = config.get('isDeployed');
 const isDevelopment = config.get('isDevelopment');
@@ -185,17 +186,23 @@ function baseServer(routes, createStore, { appInstanceName = appName } = {}) {
     app.use(Express.static(path.join(config.get('basePath'), 'dist')));
   }
 
-  // Return version information as json
-  app.get('/__version__', (req, res) => {
-    fs.stat(version, (err) => {
-      if (err) {
+  // Show version/commit information as JSON.
+  function viewVersion(req, res) {
+    fs.stat(version, (error) => {
+      if (error) {
+        log.error(`Could not stat version file ${version}: ${error}`);
         res.sendStatus(415);
       } else {
         res.setHeader('Content-Type', 'application/json');
         fs.createReadStream(version).pipe(res);
       }
     });
-  });
+  }
+
+  // Following the ops monitoring convention, return version info at this URL.
+  app.get('/__version__', viewVersion);
+  // For AMO, this helps differentiate from /__version__ served by addons-server.
+  app.get('/__frontend_version__', viewVersion);
 
   // Return 200 for csp reports - this will need to be overridden when deployed.
   app.post('/__cspreport__', (req, res) => res.status(200).end('ok'));

tests/server/amo/TestViews.js

@@ -1,4 +1,8 @@
+import fs from 'fs';
+import path from 'path';
+
 import { assert } from 'chai';
+import config from 'config';
 import request from 'supertest-as-promised';
 
 import { checkSRI, parseCSP, runTestServer } from '../helpers';
@@ -62,4 +66,45 @@ describe('AMO GET Requests', () => {
       assert.equal(res.header.location,
         '/en-US/firefox/search/');
     }));
+
+  describe('application version views', () => {
+    const versionFile = path.join(config.basePath, 'version.json');
+
+    const versionData = {
+      build: 'https://circleci.com/gh/mozilla/addons-server/6550',
+      source: 'https://github.com/mozilla/addons-server',
+      // This is typically blank for some reason.
+      version: '',
+      commit: '87f49a40ee7a5e87d9b9efde8e91b9019e8b13d1',
+    };
+
+    beforeEach(() => {
+      // Simulate how ops writes a version file in our project root.
+      fs.writeFileSync(versionFile, JSON.stringify(versionData));
+    });
+
+    afterEach(() => {
+      fs.unlinkSync(versionFile);
+    });
+
+    it('should respond to __version__ with version info', () => {
+      return request(app)
+        .get('/__version__')
+        .set('Accept', 'application/json')
+        .expect(200)
+        .then((res) => {
+          assert.deepEqual(res.body, versionData);
+        });
+    });
+
+    it('should respond to __frontend_version__ with version info', () => {
+      return request(app)
+        .get('/__frontend_version__')
+        .set('Accept', 'application/json')
+        .expect(200)
+        .then((res) => {
+          assert.deepEqual(res.body, versionData);
+        });
+    });
+  });
 });