feat: Add version headers to all responses

src/routes.ts

@@ -1,7 +1,10 @@
 import { FastifyInstance } from 'fastify';
 import segmentRoutes from './segments/routes';
 import manifestRoutes from './manifests/routes';
-import { generateHeartbeatResponse } from './shared/utils';
+import {
+  generateHeartbeatResponse,
+  addCustomVersionHeader
+} from './shared/utils';
 
 const apiPrefix = (version: number): string => `api/v${version}`;
 
@@ -17,4 +20,5 @@ export function registerRoutes(app: FastifyInstance) {
   const opts = { prefix: apiPrefix(2) };
   app.register(segmentRoutes, opts);
   app.register(manifestRoutes, opts);
+  addCustomVersionHeader(app);
 }

src/server.test.ts

@@ -0,0 +1,27 @@
+import fastify from 'fastify';
+import { registerRoutes } from './routes';
+import {
+  HLS_PROXY_MASTER,
+  HLS_PROXY_MEDIA,
+  SEGMENTS_PROXY_SEGMENT
+} from './segments/constants';
+
+describe('Chaos Stream Proxy server', () => {
+  let app = null;
+  beforeEach(() => {
+    app = fastify();
+    registerRoutes(app);
+  });
+
+  it.each([HLS_PROXY_MASTER, HLS_PROXY_MEDIA, SEGMENTS_PROXY_SEGMENT])(
+    'route %p contains x-version header',
+    async (route) => {
+      const response = await app.inject(route);
+      expect(response.headers).toEqual(
+        expect.objectContaining({
+          'x-version': process.env.npm_package_version
+        })
+      );
+    }
+  );
+});

src/shared/utils.ts

@@ -7,6 +7,12 @@ import { ReadStream } from 'fs';
 import { IncomingHttpHeaders } from 'http';
 import path from 'path';
 import { CorruptorConfigMap } from '../manifests/utils/configs';
+import {
+  FastifyReply,
+  FastifyRequest,
+  RequestPayload,
+  FastifyInstance
+} from 'fastify';
 
 // eslint-disable-next-line @typescript-eslint/no-var-requires
 const { version } = require('../../package.json');
@@ -239,3 +245,31 @@ export function segmentUrlParamString(
 
 export const SERVICE_ORIGIN =
   process.env.SERVICE_ORIGIN || 'http://localhost:8000';
+
+export function joinNotNull(strings: (string | null)[], delimiter: string) {
+  return strings.filter((s) => s != null).join(delimiter);
+}
+
+export function addCustomVersionHeader(app: FastifyInstance): void {
+  app.addHook(
+    'onSend',
+    async (
+      request: FastifyRequest,
+      reply: FastifyReply,
+      payload: RequestPayload
+    ): Promise<RequestPayload> => {
+      reply.headers({
+        'Access-Control-Allow-Headers': joinNotNull(
+          [reply.getHeader('Access-Control-Allow-Headers'), 'X-Version'],
+          ', '
+        ),
+        'Access-Control-Expose-Headers': joinNotNull(
+          [reply.getHeader('Access-Control-Expose-Headers'), 'X-Version'],
+          ', '
+        ),
+        'X-Version': process.env.npm_package_version
+      });
+      return payload;
+    }
+  );
+}