From 304b116c6d558ed5d95d427d765327a9d2ba4d25 Mon Sep 17 00:00:00 2001
From: prathamesh0 <42446521+prathamesh0@users.noreply.github.com>
Date: Tue, 5 Dec 2023 18:17:27 +0530
Subject: [PATCH] Add a CLI for running a proxy server (#495)

---
 packages/cli/README.md    | 22 +++++++++++
 packages/cli/package.json |  4 +-
 packages/cli/src/index.ts |  1 +
 packages/cli/src/proxy.ts | 79 +++++++++++++++++++++++++++++++++++++++
 yarn.lock                 | 44 +++++++++++++++++++++-
 5 files changed, 148 insertions(+), 2 deletions(-)
 create mode 100644 packages/cli/src/proxy.ts

diff --git a/packages/cli/README.md b/packages/cli/README.md
index 65ef7168..6ae971c0 100644
--- a/packages/cli/README.md
+++ b/packages/cli/README.md
@@ -94,3 +94,25 @@ A basic CLI to to fetch and compare watcher GQL response.
   ```
 
 * The diff for latest and previous GQL responses is shown
+
+## proxy
+
+Runs a proxy server pointed to the given upstream endpoint
+
+* Install dependencies and build:
+
+  ```bash
+  # In repo root
+  yarn
+
+  # In packages/cli
+  yarn build
+  ```
+
+* Run the proxy server:
+
+  ```bash
+  yarn proxy --upstream <UPSTREAM_ENDPOINT> --origin-header [ORIGN_HEADER] --port [PROXY_SERVER_PORT]
+
+  # For details, run: yarn proxy --help
+  ```
diff --git a/packages/cli/package.json b/packages/cli/package.json
index 908f0eea..1e0338c9 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -9,7 +9,8 @@
     "clean": "rm -rf ./dist",
     "copy-assets": "copyfiles -u 1 src/**/*.gql dist/",
     "chat": "DEBUG='vulcanize:*, laconic:*' node dist/chat.js",
-    "compare-gql": "DEBUG='vulcanize:*' node dist/compare-gql.js"
+    "compare-gql": "DEBUG='vulcanize:*' node dist/compare-gql.js",
+    "proxy": "DEBUG='laconic:*' node dist/proxy.js"
   },
   "dependencies": {
     "@apollo/client": "^3.7.1",
@@ -31,6 +32,7 @@
     "graphql": "^15.5.0",
     "graphql-request": "^6.1.0",
     "graphql-subscriptions": "^2.0.0",
+    "http-proxy-middleware": "^2.0.6",
     "js-yaml": "^4.0.0",
     "json-diff": "^0.5.4",
     "lodash": "^4.17.21",
diff --git a/packages/cli/src/index.ts b/packages/cli/src/index.ts
index 5b381481..0a2d219f 100644
--- a/packages/cli/src/index.ts
+++ b/packages/cli/src/index.ts
@@ -17,3 +17,4 @@ export * from './fill';
 export * from './create-state-gql';
 export * from './peer';
 export * from './utils';
+export * from './proxy';
diff --git a/packages/cli/src/proxy.ts b/packages/cli/src/proxy.ts
new file mode 100644
index 00000000..db57ddaa
--- /dev/null
+++ b/packages/cli/src/proxy.ts
@@ -0,0 +1,79 @@
+//
+// Copyright 2023 Vulcanize, Inc.
+//
+
+import debug from 'debug';
+import yargs from 'yargs';
+import { hideBin } from 'yargs/helpers';
+import express from 'express';
+import { createProxyMiddleware } from 'http-proxy-middleware';
+import cors from 'cors';
+
+const log = debug('laconic:proxy');
+
+interface Arguments {
+  port: number;
+  upstream: string;
+  originHeader?: string;
+}
+
+async function main (): Promise<void> {
+  const argv: Arguments = _getArgv();
+
+  const app = express();
+
+  // Enable CORS
+  app.use(cors());
+
+  const upstreamEndpoint: string = argv.upstream;
+  if (!upstreamEndpoint) {
+    throw new Error('Upstream endpoint not provided');
+  }
+
+  // Create a proxy
+  const proxyMiddleware = createProxyMiddleware({
+    target: upstreamEndpoint,
+    changeOrigin: true, // Enable CORS bypass
+    logLevel: 'debug', // Set log level as needed
+    onProxyReq: (proxyReq) => {
+      if (argv.originHeader) {
+        proxyReq.setHeader('Origin', argv.originHeader);
+      }
+    }
+  });
+
+  // Use the proxy middleware for incoming requests
+  app.use('/', proxyMiddleware);
+
+  // Start the server
+  app.listen(argv.port, () => {
+    log(`Proxy server listening on port ${argv.port}`);
+  });
+}
+
+function _getArgv (): any {
+  return yargs(hideBin(process.argv)).parserConfiguration({
+    'parse-numbers': false
+  }).env(
+    'PROXY'
+  ).options({
+    port: {
+      type: 'number',
+      describe: 'Port to listen on (env: PROXY_PORT)',
+      default: 4000
+    },
+    upstream: {
+      type: 'string',
+      describe: 'Upstream endpoint (env: PROXY_UPSTREAM)',
+      demandOption: true
+    },
+    originHeader: {
+      type: 'string',
+      describe: 'Origin header to be used (env: PROXY_ORIGIN_HEADER)'
+    }
+  }).argv;
+}
+
+main().catch(err => {
+  log(err);
+});
diff --git a/yarn.lock b/yarn.lock
index 71842345..bff11b65 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3671,6 +3671,13 @@
     "@types/minimatch" "*"
     "@types/node" "*"
 
+"@types/http-proxy@^1.17.8":
+  version "1.17.14"
+  resolved "https://registry.yarnpkg.com/@types/http-proxy/-/http-proxy-1.17.14.tgz#57f8ccaa1c1c3780644f8a94f9c6b5000b5e2eec"
+  integrity sha512-SSrD0c1OQzlFX7pGu1eXxSEjemej64aaNPRhhVYUGqXh0BtldAAx37MG8btcumvpgKyZp1F5Gn3JkktdxiFv6w==
+  dependencies:
+    "@types/node" "*"
+
 "@types/js-yaml@^4.0.3", "@types/js-yaml@^4.0.4":
   version "4.0.5"
   resolved "https://registry.yarnpkg.com/@types/js-yaml/-/js-yaml-4.0.5.tgz#738dd390a6ecc5442f35e7f03fa1431353f7e138"
@@ -8010,7 +8017,7 @@ eventemitter3@4.0.4:
   resolved "https://registry.npmjs.org/eventemitter3/-/eventemitter3-4.0.4.tgz"
   integrity sha512-rlaVLnVxtxvoyLsQQFBx53YmXHDxRIzzTLbdfxqi4yocpSjAxXwkU0cScM5JgSKMqEhrZpnvQ2D9gjylR0AimQ==
 
-eventemitter3@^4.0.4, eventemitter3@^4.0.7:
+eventemitter3@^4.0.0, eventemitter3@^4.0.4, eventemitter3@^4.0.7:
   version "4.0.7"
   resolved "https://registry.npmjs.org/eventemitter3/-/eventemitter3-4.0.7.tgz"
   integrity sha512-8guHBZCwKnFhYdHr2ysuRWErTwhoN2X8XELRlrRwpmfeY2jjuUN4taQMsULKUVo1K4DvZl+0pgfyoysHxvmvEw==
@@ -8401,6 +8408,11 @@ flow-stoplight@^1.0.0:
   resolved "https://registry.npmjs.org/flow-stoplight/-/flow-stoplight-1.0.0.tgz"
   integrity sha1-SiksW8/4s5+mzAyxqFPYbyfu/3s=
 
+follow-redirects@^1.0.0:
+  version "1.15.3"
+  resolved "https://registry.yarnpkg.com/follow-redirects/-/follow-redirects-1.15.3.tgz#fe2f3ef2690afce7e82ed0b44db08165b207123a"
+  integrity sha512-1VzOtuEM8pC9SFU1E+8KfTjZyMztRsgEfwQl44z8A25uy13jSzTj6dyK2Df52iV0vgHCfBwLhDWevLn95w5v6Q==
+
 follow-redirects@^1.12.1:
   version "1.15.2"
   resolved "https://registry.yarnpkg.com/follow-redirects/-/follow-redirects-1.15.2.tgz#b460864144ba63f2681096f274c4e57026da2c13"
@@ -9418,6 +9430,26 @@ http-proxy-agent@^4.0.1:
     agent-base "6"
     debug "4"
 
+http-proxy-middleware@^2.0.6:
+  version "2.0.6"
+  resolved "https://registry.yarnpkg.com/http-proxy-middleware/-/http-proxy-middleware-2.0.6.tgz#e1a4dd6979572c7ab5a4e4b55095d1f32a74963f"
+  integrity sha512-ya/UeJ6HVBYxrgYotAZo1KvPWlgB48kUJLDePFeneHsVujFaW5WNj2NgWCAE//B1Dl02BIfYlpNgBy8Kf8Rjmw==
+  dependencies:
+    "@types/http-proxy" "^1.17.8"
+    http-proxy "^1.18.1"
+    is-glob "^4.0.1"
+    is-plain-obj "^3.0.0"
+    micromatch "^4.0.2"
+
+http-proxy@^1.18.1:
+  version "1.18.1"
+  resolved "https://registry.yarnpkg.com/http-proxy/-/http-proxy-1.18.1.tgz#401541f0534884bbf95260334e72f88ee3976549"
+  integrity sha512-7mz/721AbnJwIVbnaSv1Cz3Am0ZLT/UBwkC92VlxhXv/k/BBQfM2fXElQNC27BVGr0uwUpplYPQM9LnaBMR5NQ==
+  dependencies:
+    eventemitter3 "^4.0.0"
+    follow-redirects "^1.0.0"
+    requires-port "^1.0.0"
+
 http-signature@~1.2.0:
   version "1.2.0"
   resolved "https://registry.npmjs.org/http-signature/-/http-signature-1.2.0.tgz"
@@ -10107,6 +10139,11 @@ is-plain-obj@^2.0.0, is-plain-obj@^2.1.0:
   resolved "https://registry.npmjs.org/is-plain-obj/-/is-plain-obj-2.1.0.tgz"
   integrity sha512-YWnfyRwxL/+SsrWYfOpUtz5b3YD+nyfkHvjbcanzk8zgyO4ASD67uVMRt8k5bM4lLMDnXfriRhOpemw+NfT1eA==
 
+is-plain-obj@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/is-plain-obj/-/is-plain-obj-3.0.0.tgz#af6f2ea14ac5a646183a5bbdb5baabbc156ad9d7"
+  integrity sha512-gwsOE28k+23GP1B6vFl1oVh/WOzmawBrKwo5Ev6wMKzPkaXaCDIQKzLnvsA42DRlbVTWorkgTKIviAKCWkfUwA==
+
 is-plain-object@^2.0.1, is-plain-object@^2.0.3, is-plain-object@^2.0.4:
   version "2.0.4"
   resolved "https://registry.npmjs.org/is-plain-object/-/is-plain-object-2.0.4.tgz"
@@ -14207,6 +14244,11 @@ require-package-name@^2.0.1:
   resolved "https://registry.yarnpkg.com/require-package-name/-/require-package-name-2.0.1.tgz#c11e97276b65b8e2923f75dabf5fb2ef0c3841b9"
   integrity sha512-uuoJ1hU/k6M0779t3VMVIYpb2VMJk05cehCaABFhXaibcbvfgR8wKiozLjVFSzJPmQMRqIcO0HMyTFqfV09V6Q==
 
+requires-port@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/requires-port/-/requires-port-1.0.0.tgz#925d2601d39ac485e091cf0da5c6e694dc3dcaff"
+  integrity sha512-KigOCHcocU3XODJxsu8i/j8T9tzT4adHiecwORRQ0ZZFcp7ahwXuRU1m+yuO90C5ZUyGeGfocHDI14M3L3yDAQ==
+
 resolve-cwd@^3.0.0:
   version "3.0.0"
   resolved "https://registry.npmjs.org/resolve-cwd/-/resolve-cwd-3.0.0.tgz"