Add linkup command to improve link functionality

src/node/link.ts

@@ -0,0 +1,22 @@
+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`], {
+    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()
+    })
+  })
+}