Add linkup command to enable linking

The linkup command is the successor to coder-cloud. It enables port-forwarding via URL, uses WebRTC internally, and will enable greater linking functionality longer-term. A Link extension will be published once this is merged. We are not removing the old link functionality yet... we eventually will, but want to ensure a smooth transition.

.gitignore

@@ -12,6 +12,7 @@ node_modules
 node-*
 /plugins
 /lib/coder-cloud-agent
+/lib/linkup
 .home
 coverage
 **/.DS_Store

ci/build/build-code-server.sh

@@ -29,6 +29,20 @@ main() {
     set -e
   fi
 
+  if ! [ -f ./lib/linkup ]; then
+    echo "Downloading Link agent..."
+
+    # for arch; we do not use OS from lib.sh and get our own.
+    # lib.sh normalizes macos to darwin - but cloud-agent's binaries do not
+    source ./ci/lib.sh
+    OS="$(uname | tr '[:upper:]' '[:lower:]')"
+
+    set +e
+    curl -fsSL "https://storage.googleapis.com/coder-link-releases/latest/linkup-$OS-$ARCH" -o ./lib/linkup
+    chmod +x ./lib/linkup
+    set -e
+  fi
+
   yarn browserify out/browser/register.js -o out/browser/register.browserified.js
   yarn browserify out/browser/pages/login.js -o out/browser/pages/login.browserified.js
   yarn browserify out/browser/pages/vscode.js -o out/browser/pages/vscode.browserified.js

ci/build/build-release.sh

@@ -60,6 +60,7 @@ EOF
     rsync node_modules/ "$RELEASE_PATH/node_modules"
     mkdir -p "$RELEASE_PATH/lib"
     rsync ./lib/coder-cloud-agent "$RELEASE_PATH/lib"
+    rsync ./lib/linkup "$RELEASE_PATH/lib"
   fi
 }
 

ci/build/npm-postinstall.sh

@@ -63,6 +63,12 @@ main() {
     echo "Failed to download cloud agent; --link will not work"
   fi
 
+  if curl -fsSL "https://storage.googleapis.com/coder-link-releases/latest/linkup-$OS-$ARCH" -o ./lib/linkup; then
+    chmod +x ./lib/linkup
+  else
+    echo "Failed to download Link agent; the Link extension will not work"
+  fi
+
   if ! vscode_yarn; then
     echo "You may not have the required dependencies to build the native modules."
     echo "Please see https://github.com/cdr/code-server/blob/master/docs/npm.md"

src/node/link.ts

@@ -0,0 +1,23 @@
+import { logger } from "@coder/logger"
+import { spawn } from "child_process"
+import path from "path"
+
+export function startLink(port: number): Promise<void> {
+  logger.debug(`running link targetting ${port}`)
+
+  const agent = spawn(path.resolve(__dirname, "../../lib/linkup"), ["--devurl", `code:${port}:code-server`], {
+    stdio: "ignore",
+    shell: false,
+  })
+  return new Promise((res, rej) => {
+    agent.on("error", rej)
+    agent.on("close", (code) => {
+      if (code !== 0) {
+        return rej({
+          message: `Link exited with ${code}`,
+        })
+      }
+      res()
+    })
+  })
+}

src/node/main.ts

@@ -8,6 +8,7 @@ import { createApp, ensureAddress } from "./app"
 import { AuthType, DefaultedArgs, Feature } from "./cli"
 import { coderCloudBind } from "./coder_cloud"
 import { commit, version } from "./constants"
+import { startLink } from "./link"
 import { register } from "./routes"
 import { humanPath, isFile, open } from "./util"
 
@@ -128,6 +129,15 @@ export const runCodeServer = async (args: DefaultedArgs): Promise<http.Server> =
     await coderCloudBind(serverAddress.replace(/^https?:\/\//, ""), args.link.value)
     logger.info("  - Connected to cloud agent")
   }
+  
+  try {
+    const port = parseInt(serverAddress.split(":").pop() as string, 10)
+    startLink(port).catch((ex) => {
+      logger.debug("Link daemon exited!", field("error", ex))
+    })
+  } catch (ex) {
+    logger.debug("Failed to start link daemon!", ex)
+  }
 
   if (args.enable && args.enable.length > 0) {
     logger.info("Enabling the following experimental features:")