coder · nhooyr · Dec 18, 2020 · Dec 18, 2020 · Dec 18, 2020 · Dec 18, 2020
diff --git a/doc/FAQ.md b/doc/FAQ.md
@@ -27,6 +27,7 @@
 - [Isn't an install script piped into sh insecure?](#isnt-an-install-script-piped-into-sh-insecure)
 - [How do I make my keyboard shortcuts work?](#how-do-i-make-my-keyboard-shortcuts-work)
 - [Differences compared to Theia?](#differences-compared-to-theia)
+- [`$HTTP_PROXY`, `$HTTPS_PROXY`, `$NO_PROXY`](#http_proxy-https_proxy-no_proxy)
 - [Enterprise](#enterprise)
 
 <!-- END doctoc generated TOC please keep comment here to allow auto update -->
@@ -338,6 +339,30 @@ You can't just use your VS Code config in Theia like you can with code-server.
 To summarize, code-server is a patched fork of VS Code to run in the browser whereas
 Theia takes some parts of VS Code but is an entirely different editor.
 
+## `$HTTP_PROXY`, `$HTTPS_PROXY`, `$NO_PROXY`
+
+code-server supports the standard environment variables to allow directing
+server side requests through a proxy.
+
+```sh
+export HTTP_PROXY=https://134.8.5.4
+export HTTPS_PROXY=https://134.8.5.4
+# Now all of code-server's server side requests will go through
+# https://134.8.5.4 first.
+code-server
+```
+
+- See [proxy-from-env](https://www.npmjs.com/package/proxy-from-env#environment-variables)
+  for a detailed reference on the various environment variables and their syntax.
+  - code-server only uses the `http` and `https` protocols.
+- See [proxy-agent](https://www.npmjs.com/package/proxy-agent) for the various supported
+  proxy protocols.
+
+**note**: Only server side requests will be proxied! This includes fetching extensions,
+requests made from extensions etc. To proxy requests from your browser you need to
+configure your browser separately. Browser requests would cover exploring the extension
+marketplace.
+
 ## Enterprise
 
 Visit [our enterprise page](https://coder.com) for more information about our

diff --git a/lib/vscode/package.json b/lib/vscode/package.json
@@ -65,6 +65,7 @@
     "native-watchdog": "1.3.0",
     "node-pty": "0.10.0-beta17",
     "proxy-agent": "^4.0.0",
+    "proxy-from-env": "^1.1.0",
     "rimraf": "^2.2.8",
     "spdlog": "^0.11.1",
     "sudo-prompt": "9.1.1",
@@ -95,6 +96,7 @@
     "@types/minimist": "^1.2.0",
     "@types/mocha": "2.2.39",
     "@types/node": "^12.11.7",
+    "@types/proxy-from-env": "^1.0.1",
     "@types/sinon": "^1.16.36",
     "@types/trusted-types": "^1.0.6",
     "@types/vscode-windows-registry": "^1.0.0",

diff --git a/lib/vscode/yarn.lock b/lib/vscode/yarn.lock
@@ -302,6 +302,13 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-13.13.28.tgz#b6d0628b0371d6c629d729c98322de314b640219"
   integrity sha512-EM/qFeRH8ZCD+TlsaIPULyyFm9vOhFIvgskY2JmHbEsWsOPgN+rtjSXrcHGgJpob4Nu17VfO95FKewr0XY7iOQ==
 
+"@types/proxy-from-env@^1.0.1":
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/@types/proxy-from-env/-/proxy-from-env-1.0.1.tgz#b5f3e99230ca4518af196c18267055fc51f892b7"
+  integrity sha512-luG++TFHyS61eKcfkR1CVV6a1GMNXDjtqEQIIfaSHax75xp0HU3SlezjOi1yqubJwrG8e9DeW59n6wTblIDwFg==
+  dependencies:
+    "@types/node" "*"
+
 "@types/semver@^5.4.0", "@types/semver@^5.5.0":
   version "5.5.0"
   resolved "https://registry.yarnpkg.com/@types/semver/-/semver-5.5.0.tgz#146c2a29ee7d3bae4bf2fcb274636e264c813c45"

diff --git a/package.json b/package.json
@@ -40,6 +40,7 @@
     "@types/node": "^12.12.7",
     "@types/parcel-bundler": "^1.12.1",
     "@types/pem": "^1.9.5",
+    "@types/proxy-from-env": "^1.0.1",
     "@types/safe-compare": "^1.1.0",
     "@types/semver": "^7.1.0",
     "@types/split2": "^2.1.6",
@@ -82,6 +83,7 @@
     "limiter": "^1.1.5",
     "pem": "^1.14.2",
     "proxy-agent": "^4.0.0",
+    "proxy-from-env": "^1.1.0",
     "qs": "6.7.0",
     "rotating-file-stream": "^2.1.1",
     "safe-buffer": "^5.1.1",

diff --git a/src/node/proxy_agent.ts b/src/node/proxy_agent.ts
@@ -1,12 +1,15 @@
 import { logger } from "@coder/logger"
 import * as http from "http"
-import * as proxyagent from "proxy-agent"
+import * as proxyAgent from "proxy-agent"
+import * as proxyFromEnv from "proxy-from-env"
 
 /**
- * This file does not have anything to do with the code-server proxy.
- * It's for $HTTP_PROXY support!
+ * This file has nothing to do with the code-server proxy.
+ * It is to support $HTTP_PROXY, $HTTPS_PROXY and $NO_PROXY.
+ *
  * - https://github.com/cdr/code-server/issues/124
  * - https://www.npmjs.com/package/proxy-agent
+ * - https://www.npmjs.com/package/proxy-from-env
  *
  * This file exists in two locations:
  * - src/node/proxy_agent.ts
@@ -15,48 +18,64 @@ import * as proxyagent from "proxy-agent"
  */
 
 /**
- * monkeyPatch patches the node HTTP/HTTPS library to route all requests through our
- * custom agent from the proxyAgent package.
+ * monkeyPatch patches the node http,https modules to route all requests through the
+ * agent we get from the proxy-agent package.
+ *
+ * This approach only works if there is no code specifying an explicit agent when making
+ * a request.
+ *
+ * None of our code ever passes in a explicit agent to the http,https modules.
+ * VS Code's does sometimes but only when a user sets the http.proxy configuration.
+ * See https://code.visualstudio.com/docs/setup/network#_legacy-proxy-server-support
+ *
+ * Even if they do, it's probably the same proxy so we should be fine! And those knobs
+ * are deprecated anyway.
  */
-export function monkeyPatch(vscode: boolean): void {
-  // We do not support HTTPS_PROXY here to avoid confusion. proxy-agent will automatically
-  // use the correct protocol to connect to the proxy depending on the requested URL.
-  //
-  // We could implement support ourselves to allow people to configure the proxy used for
-  // HTTPS vs HTTP but there doesn't seem to be much value in that.
-  //
-  // At least of right now, it'd just be plain confusing to support HTTPS_PROXY when proxy-agent
-  // will still use HTTP to hit it for HTTP requests.
-  const proxyURL = process.env.HTTP_PROXY || process.env.http_proxy
-  if (!proxyURL) {
-    return
-  }
+export function monkeyPatch(inVSCode: boolean): void {
+  if (shouldEnableProxy()) {
+    const http = require("http")
+    const https = require("https")
 
-  logger.debug(`using $HTTP_PROXY ${process.env.HTTP_PROXY}`)
+    // If we do not pass in a proxy URL, proxy-agent will get the URL from the environment.
+    // See https://www.npmjs.com/package/proxy-from-env.
+    // Also see shouldEnableProxy.
+    const pa = newProxyAgent(inVSCode)
+    http.globalAgent = pa
+    https.globalAgent = pa
+  }
+}
 
-  let pa: http.Agent
+function newProxyAgent(inVSCode: boolean): http.Agent {
   // The reasoning for this split is that VS Code's build process does not have
   // esModuleInterop enabled but the code-server one does. As a result depending on where
   // we execute, we either have a default attribute or we don't.
   //
   // I can't enable esModuleInterop in VS Code's build process as it breaks and spits out
-  // a huge number of errors.
-  if (vscode) {
-    pa = new (proxyagent as any)(process.env.HTTP_PROXY)
+  // a huge number of errors. And we can't use require as otherwise the modules won't be
+  // included in the final product.
+  if (inVSCode) {
+    return new (proxyAgent as any)()
   } else {
-    pa = new (proxyagent as any).default(process.env.HTTP_PROXY)
+    return new (proxyAgent as any).default()
+  }
+}
+
+// If they have $NO_PROXY set to example.com then this check won't work!
+// But that's drastically unlikely.
+function shouldEnableProxy(): boolean {
+  let shouldEnable = false
+
+  const httpProxy = proxyFromEnv.getProxyForUrl(`http://example.com`)
+  if (httpProxy) {
+    shouldEnable = true
+    logger.debug(`using $HTTP_PROXY ${httpProxy}`)
+  }
+
+  const httpsProxy = proxyFromEnv.getProxyForUrl(`https://example.com`)
+  if (httpsProxy) {
+    shouldEnable = true
+    logger.debug(`using $HTTPS_PROXY ${httpsProxy}`)
   }
 
-  /**
-   * None of our code ever passes in a explicit agent to the http modules but VS Code's
-   * does sometimes but only when a user sets the http.proxy configuration.
-   * See https://code.visualstudio.com/docs/setup/network#_legacy-proxy-server-support
-   *
-   * Even if they do, it's probably the same proxy so we should be fine! And those are
-   * deprecated anyway.
-   */
-  const http = require("http")
-  const https = require("https")
-  http.globalAgent = pa
-  https.globalAgent = pa
+  return shouldEnable
 }
diff --git a/yarn.lock b/yarn.lock
@@ -1137,6 +1137,13 @@
   dependencies:
     "@types/node" "*"
 
+"@types/proxy-from-env@^1.0.1":
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/@types/proxy-from-env/-/proxy-from-env-1.0.1.tgz#b5f3e99230ca4518af196c18267055fc51f892b7"
+  integrity sha512-luG++TFHyS61eKcfkR1CVV6a1GMNXDjtqEQIIfaSHax75xp0HU3SlezjOi1yqubJwrG8e9DeW59n6wTblIDwFg==
+  dependencies:
+    "@types/node" "*"
+
 "@types/q@^1.5.1":
   version "1.5.4"
   resolved "https://registry.yarnpkg.com/@types/q/-/q-1.5.4.tgz#15925414e0ad2cd765bfef58842f7e26a7accb24"
@@ -6333,7 +6340,7 @@ proxy-agent@^4.0.0:
     proxy-from-env "^1.0.0"
     socks-proxy-agent "^5.0.0"
 
-proxy-from-env@^1.0.0:
+proxy-from-env@^1.0.0, proxy-from-env@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/proxy-from-env/-/proxy-from-env-1.1.0.tgz#e102f16ca355424865755d2c9e8ea4f24d58c3e2"
   integrity sha512-D+zkORCbA9f1tdWRK0RaCR3GPv50cMxcrz4X8k5LTSUD1Dkw47mKJEZQNunItRTkWwgtaUSo1RVFRIG9ZXiFYg==