feat: added option for undici proxy agent (#363)

Closes #159

Signed-off-by: Jamie King <[email protected]>

README.md

@@ -82,7 +82,7 @@ proxy.register(require('@fastify/reply-from'), {
 
 #### `undici`
 
-By default, [undici](https://github.com/mcollina/undici) will be used to perform the HTTP/1.1
+By default, [undici](https://github.com/nodejs/undici) will be used to perform the HTTP/1.1
 requests. Enabling this flag should guarantee
 20-50% more throughput.
 
@@ -102,6 +102,18 @@ proxy.register(require('@fastify/reply-from'), {
   }
 })
 ```
+
+You can also include a proxy for the undici client:
+
+```js
+proxy.register(require('@fastify/reply-from'), {
+  base: 'http://localhost:3001/',
+  undici: {
+    proxy: 'http://my.proxy.server:8080',
+  }
+})
+```
+
 See undici own options for more configurations.
 
 You can also pass the plugin a custom instance:

lib/request.js

@@ -83,7 +83,11 @@ function buildRequest (opts) {
     } else if (isUndiciInstance(opts.undici)) {
       undiciInstance = opts.undici
     } else if (!globalAgent) {
-      undiciAgent = new undici.Agent(getUndiciOptions(opts.undici))
+      if (undiciOpts.proxy) {
+        undiciAgent = new undici.ProxyAgent(getUndiciProxyOptions(opts.undici))
+      } else {
+        undiciAgent = new undici.Agent(getUndiciOptions(opts.undici))
+      }
     } else {
       undiciAgent = undici.getGlobalDispatcher()
     }
@@ -304,6 +308,13 @@ function getAgentOptions (opts) {
   }
 }
 
+function getUndiciProxyOptions ({ proxy, ...opts }) {
+  if (typeof proxy === 'string' || proxy instanceof URL) {
+    return getUndiciOptions({ uri: proxy, ...opts })
+  }
+  return getUndiciOptions({ ...proxy, ...opts })
+}
+
 function getUndiciOptions (opts = {}) {
   const res = {
     pipelining: 1,

package.json

@@ -7,7 +7,7 @@
   "types": "types/index.d.ts",
   "scripts": {
     "lint": "standard | snazzy",
-    "lint:fix": "standard --fix",
+    "lint:fix": "standard --fix | snazzy",
     "test": "npm run test:unit && npm run test:typescript",
     "test:unit": "tap",
     "test:typescript": "tsd"
@@ -41,6 +41,7 @@
     "h2url": "^0.2.0",
     "msgpack5": "^6.0.1",
     "nock": "^13.2.6",
+    "proxy": "^2.1.1",
     "proxyquire": "^2.1.3",
     "semver": "^7.5.1",
     "simple-get": "^4.0.1",

test/undici-proxy-agent.test.js

@@ -0,0 +1,79 @@
+'use strict'
+
+const { test } = require('tap')
+const { createServer } = require('node:http')
+const Fastify = require('fastify')
+const get = require('simple-get').concat
+const { createProxy } = require('proxy')
+const From = require('..')
+
+const configFormat = {
+  string: (value) => value,
+  'url instance': (value) => new URL(value),
+  object: (value) => ({ uri: value })
+}
+
+for (const [description, format] of Object.entries(configFormat)) {
+  test(`use undici ProxyAgent to connect through proxy - configured via ${description}`, async (t) => {
+    t.plan(5)
+    const target = await buildServer()
+    const proxy = await buildProxy()
+    t.teardown(target.close.bind(target))
+    t.teardown(proxy.close.bind(proxy))
+
+    const targetUrl = `http://localhost:${target.address().port}`
+    const proxyUrl = `http://localhost:${proxy.address().port}`
+
+    proxy.on('connect', () => {
+      t.ok(true, 'should connect to proxy')
+    })
+
+    target.on('request', (req, res) => {
+      res.setHeader('content-type', 'application/json')
+      res.end(JSON.stringify({ hello: 'world' }))
+    })
+
+    const instance = Fastify()
+    t.teardown(instance.close.bind(instance))
+
+    instance.register(From, {
+      base: targetUrl,
+      undici: {
+        proxy: format(proxyUrl)
+      }
+    })
+
+    instance.get('/', (request, reply) => {
+      reply.from()
+    })
+
+    const executionFlow = () => new Promise((resolve) => {
+      instance.listen({ port: 0 }, err => {
+        t.error(err)
+
+        get(`http://localhost:${instance.server.address().port}`, (err, res, data) => {
+          t.error(err)
+          t.same(res.statusCode, 200)
+          t.match(JSON.parse(data.toString()), { hello: 'world' })
+          resolve()
+        })
+      })
+    })
+
+    await executionFlow()
+  })
+}
+
+function buildServer () {
+  return new Promise((resolve) => {
+    const server = createServer()
+    server.listen(0, () => resolve(server))
+  })
+}
+
+function buildProxy () {
+  return new Promise((resolve) => {
+    const server = createProxy(createServer())
+    server.listen(0, () => resolve(server))
+  })
+}

types/index.d.ts

@@ -28,6 +28,7 @@ import {
   RequestOptions as SecureRequestOptions
 } from "https";
 import { Pool } from 'undici';
+import { ProxyAgent } from 'undici';
 
 declare module "fastify" {
   interface FastifyReply {
@@ -103,7 +104,7 @@ declare namespace fastifyReplyFrom {
     disableCache?: boolean;
     http?: HttpOptions;
     http2?: Http2Options | boolean;
-    undici?: Pool.Options;
+    undici?: Pool.Options & { proxy?: string  | URL | ProxyAgent.Options };
     contentTypesToEncode?: string[];
     retryMethods?: (HTTPMethods | 'TRACE')[];
     maxRetriesOn503?: number;

types/index.test-d.ts

@@ -38,7 +38,8 @@ const fullOptions: FastifyReplyFromOptions = {
   disableCache: false,
   undici: {
     connections: 100,
-    pipelining: 10
+    pipelining: 10,
+    proxy: 'http://example2.com:8080'
   },
   contentTypesToEncode: ['application/x-www-form-urlencoded'],
   retryMethods: ['GET', 'HEAD', 'OPTIONS', 'TRACE'],
@@ -60,6 +61,10 @@ async function main() {
 
   server.register(replyFrom, fullOptions);
 
+  server.register(replyFrom, { undici: { proxy: new URL('http://example2.com:8080') } });
+
+  server.register(replyFrom, { undici: { proxy: { uri: 'http://example2.com:8080' } } });
+
   server.get("/v1", (request, reply) => {
       expectType<FastifyReply>(reply.from());
   });