Add CORS support to the standalone server

README.md

@@ -133,6 +133,10 @@ graphql(schema, `
   if you are running your own MusicBrainz mirror. Defaults to `http://musicbrainz.org/ws/2/`.
 * **`GRAPHBRAINZ_PATH`**: The URL route at which to expose the GraphQL endpoint,
   if running the standalone server. Defaults to `/`.
+* **`GRAPHBRAINZ_CORS_ORIGIN`**: The value of the `origin` option to pass to the
+  [CORS][cors] middleware. Valid values are `true` to reflect the request
+  origin, a specific origin string to allow, `*` to allow all origins, and
+  `false` to disable CORS (the default).
 * **`GRAPHBRAINZ_CACHE_SIZE`**: The maximum number of REST API responses to
   cache. Increasing the cache size and TTL will greatly lower query execution
   time for complex queries involving frequently accessed entities. Defaults to
@@ -417,3 +421,4 @@ info.
 [mirror]: https://musicbrainz.org/doc/MusicBrainz_Server/Setup
 [aliases]: http://graphql.org/learn/queries/#aliases
 [schema tests]: test/schema.js
+[cors]: https://github.com/expressjs/cors

package.json

@@ -70,6 +70,7 @@
   "dependencies": {
     "babel-runtime": "^6.25.0",
     "compression": "^1.7.0",
+    "cors": "^2.8.4",
     "dashify": "^0.2.2",
     "dataloader": "^1.3.0",
     "debug": "^3.0.0",

src/index.js

@@ -1,6 +1,7 @@
 import express from 'express'
 import graphqlHTTP from 'express-graphql'
 import compression from 'compression'
+import cors from 'cors'
 import MusicBrainz from './api'
 import schema, { createSchema } from './schema'
 import { createContext } from './context'
@@ -56,8 +57,22 @@ export function start () {
   const app = express()
   const port = process.env.PORT || 3000
   const route = process.env.GRAPHBRAINZ_PATH || '/'
+  const corsOptions = {
+    origin: process.env.GRAPHBRAINZ_CORS_ORIGIN || false,
+    methods: 'HEAD,GET,POST'
+  }
+  switch (corsOptions.origin) {
+    case 'true':
+      corsOptions.origin = true
+      break
+    case 'false':
+      corsOptions.origin = false
+      break
+    default:
+      break
+  }
   app.use(compression())
-  app.use(route, middleware())
+  app.use(route, cors(corsOptions), middleware())
   app.listen(port)
   console.log(`Listening on port ${port}.`)
 }

yarn.lock

@@ -1593,6 +1593,13 @@ core-util-is@~1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"
 
+cors@^2.8.4:
+  version "2.8.4"
+  resolved "https://registry.yarnpkg.com/cors/-/cors-2.8.4.tgz#2bd381f2eb201020105cd50ea59da63090694686"
+  dependencies:
+    object-assign "^4"
+    vary "^1"
+
 coveralls@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/coveralls/-/coveralls-3.0.0.tgz#22ef730330538080d29b8c151dc9146afde88a99"
@@ -3816,7 +3823,7 @@ oauth-sign@~0.8.2:
   version "0.8.2"
   resolved "https://registry.yarnpkg.com/oauth-sign/-/oauth-sign-0.8.2.tgz#46a6ab7f0aead8deae9ec0565780b7d4efeb9d43"
 
-object-assign@^4.0.1, object-assign@^4.1.0:
+object-assign@^4, object-assign@^4.0.1, object-assign@^4.1.0:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/object-assign/-/object-assign-4.1.1.tgz#2109adc7965887cfc05cbbd442cac8bfbb360863"
 
@@ -5248,7 +5255,7 @@ validate-npm-package-license@^3.0.1:
     spdx-correct "~1.0.0"
     spdx-expression-parse "~1.0.0"
 
-vary@~1.1.2:
+vary@^1, vary@~1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/vary/-/vary-1.1.2.tgz#2299f02c6ded30d4a5961b0b9f74524a18f634fc"