Refactor wrapper

- Immediately create ipcMain so it doesn't have to be a function which I
  think feels cleaner.
  - Move exit handling to a separate function to compensate (otherwise
    the VS Code CLI for example won't be able to exit on its own).
- New isChild prop that is clearer than checking for parentPid (IMO).
- Skip all the checks that aren't necessary for the child process (like
  --help, --version, etc).
  - Since we check if we're the child in entry go ahead and move the
    wrap code into entry as well since that's basically what it does.
- Use a single catch at the end of the entry.
- Split out the VS Code CLI and existing instance code into separate
  functions.

src/node/cli.ts

@@ -496,3 +496,23 @@ async function copyOldMacOSDataDir(): Promise<void> {
     await fs.copy(oldDataDir, paths.data)
   }
 }
+
+export const shouldRunVsCodeCli = (args: Args): boolean => {
+  return !!args["list-extensions"] || !!args["install-extension"] || !!args["uninstall-extension"]
+}
+
+/**
+ * Determine if it looks like the user is trying to open a file or folder in an
+ * existing instance. The arguments here should be the arguments the user
+ * explicitly passed on the command line, not defaults or the configuration.
+ */
+export const shouldOpenInExistingInstance = async (args: Args): Promise<string | undefined> => {
+  // Always use the existing instance if we're running from VS Code's terminal.
+  if (process.env.VSCODE_IPC_HOOK_CLI) {
+    return process.env.VSCODE_IPC_HOOK_CLI
+  }
+
+  // TODO: implement
+
+  return undefined
+}

src/node/entry.ts

@@ -11,12 +11,21 @@ import { ProxyHttpProvider } from "./app/proxy"
 import { StaticHttpProvider } from "./app/static"
 import { UpdateHttpProvider } from "./app/update"
 import { VscodeHttpProvider } from "./app/vscode"
-import { Args, bindAddrFromAllSources, optionDescriptions, parse, readConfigFile, setDefaults } from "./cli"
+import {
+  Args,
+  bindAddrFromAllSources,
+  optionDescriptions,
+  parse,
+  readConfigFile,
+  setDefaults,
+  shouldOpenInExistingInstance,
+  shouldRunVsCodeCli,
+} from "./cli"
 import { coderCloudBind } from "./coder-cloud"
 import { AuthType, HttpServer, HttpServerOptions } from "./http"
 import { loadPlugins } from "./plugin"
 import { generateCertificate, hash, humanPath, open } from "./util"
-import { ipcMain, wrap } from "./wrapper"
+import { ipcMain, WrapperProcess } from "./wrapper"
 
 let pkg: { version?: string; commit?: string } = {}
 try {
@@ -28,6 +37,86 @@ try {
 const version = pkg.version || "development"
 const commit = pkg.commit || "development"
 
+export const runVsCodeCli = (args: Args): void => {
+  logger.debug("forking vs code cli...")
+  const vscode = cp.fork(path.resolve(__dirname, "../../lib/vscode/out/vs/server/fork"), [], {
+    env: {
+      ...process.env,
+      CODE_SERVER_PARENT_PID: process.pid.toString(),
+    },
+  })
+  vscode.once("message", (message: any) => {
+    logger.debug("got message from VS Code", field("message", message))
+    if (message.type !== "ready") {
+      logger.error("Unexpected response waiting for ready response", field("type", message.type))
+      process.exit(1)
+    }
+    const send: CliMessage = { type: "cli", args }
+    vscode.send(send)
+  })
+  vscode.once("error", (error) => {
+    logger.error("Got error from VS Code", field("error", error))
+    process.exit(1)
+  })
+  vscode.on("exit", (code) => process.exit(code || 0))
+}
+
+export const openInExistingInstance = async (args: Args, socketPath: string): Promise<void> => {
+  const pipeArgs: OpenCommandPipeArgs & { fileURIs: string[] } = {
+    type: "open",
+    folderURIs: [],
+    fileURIs: [],
+    forceReuseWindow: args["reuse-window"],
+    forceNewWindow: args["new-window"],
+  }
+
+  const isDir = async (path: string): Promise<boolean> => {
+    try {
+      const st = await fs.stat(path)
+      return st.isDirectory()
+    } catch (error) {
+      return false
+    }
+  }
+
+  for (let i = 0; i < args._.length; i++) {
+    const fp = path.resolve(args._[i])
+    if (await isDir(fp)) {
+      pipeArgs.folderURIs.push(fp)
+    } else {
+      pipeArgs.fileURIs.push(fp)
+    }
+  }
+
+  if (pipeArgs.forceNewWindow && pipeArgs.fileURIs.length > 0) {
+    logger.error("--new-window can only be used with folder paths")
+    process.exit(1)
+  }
+
+  if (pipeArgs.folderURIs.length === 0 && pipeArgs.fileURIs.length === 0) {
+    logger.error("Please specify at least one file or folder")
+    process.exit(1)
+  }
+
+  const vscode = http.request(
+    {
+      path: "/",
+      method: "POST",
+      socketPath,
+    },
+    (response) => {
+      response.on("data", (message) => {
+        logger.debug("got message from VS Code", field("message", message.toString()))
+      })
+    },
+  )
+  vscode.on("error", (error: unknown) => {
+    logger.error("got error from VS Code", field("error", error))
+  })
+  vscode.write(JSON.stringify(pipeArgs))
+  vscode.end()
+}
+
 const main = async (args: Args, configArgs: Args): Promise<void> => {
   if (args.link) {
     // If we're being exposed to the cloud, we listen on a random address and disable auth.
@@ -92,7 +181,7 @@ const main = async (args: Args, configArgs: Args): Promise<void> => {
 
   await loadPlugins(httpServer, args)
 
-  ipcMain().onDispose(() => {
+  ipcMain.onDispose(() => {
     httpServer.dispose().then((errors) => {
       errors.forEach((error) => logger.error(error.message))
     })
@@ -132,7 +221,9 @@ const main = async (args: Args, configArgs: Args): Promise<void> => {
   if (serverAddress && !options.socket && args.open) {
     // The web socket doesn't seem to work if browsing with 0.0.0.0.
     const openAddress = serverAddress.replace(/:\/\/0.0.0.0/, "://localhost")
-    await open(openAddress).catch(console.error)
+    await open(openAddress).catch((error: Error) => {
+      logger.error("Failed to open", field("address", openAddress), field("error", error))
+    })
     logger.info(`Opened ${openAddress}`)
   }
 
@@ -141,27 +232,32 @@ const main = async (args: Args, configArgs: Args): Promise<void> => {
       await coderCloudBind(serverAddress!, args.link.value)
     } catch (err) {
       logger.error(err.message)
-      ipcMain().exit(1)
+      ipcMain.exit(1)
     }
   }
 }
 
 async function entry(): Promise<void> {
-  const tryParse = async (): Promise<[Args, Args]> => {
-    try {
+  const tryParse = async (): Promise<[Args, Args, Args]> => {
     const cliArgs = parse(process.argv.slice(2))
     const configArgs = await readConfigFile(cliArgs.config)
     // This prioritizes the flags set in args over the ones in the config file.
     let args = Object.assign(configArgs, cliArgs)
     args = await setDefaults(args)
-      return [args, configArgs]
-    } catch (error) {
-      console.error(error.message)
-      process.exit(1)
-    }
+    return [args, cliArgs, configArgs]
+  }
+
+  const [args, cliArgs, configArgs] = await tryParse()
+
+  // There's no need to check flags like --help or to spawn in an existing
+  // instance for the child process because these would have already happened in
+  // the parent and the child wouldn't have been spawned.
+  if (ipcMain.isChild) {
+    await ipcMain.handshake()
+    ipcMain.preventExit()
+    return main(args, configArgs)
   }
 
-  const [args, configArgs] = await tryParse()
   if (args.help) {
     console.log("code-server", version, commit)
     console.log("")
@@ -171,7 +267,10 @@ async function entry(): Promise<void> {
     optionDescriptions().forEach((description) => {
       console.log("", description)
     })
-  } else if (args.version) {
+    return
+  }
+
+  if (args.version) {
     if (args.json) {
       console.log({
         codeServer: version,
@@ -181,83 +280,23 @@ async function entry(): Promise<void> {
     } else {
       console.log(version, commit)
     }
-    process.exit(0)
-  } else if (args["list-extensions"] || args["install-extension"] || args["uninstall-extension"]) {
-    logger.debug("forking vs code cli...")
-    const vscode = cp.fork(path.resolve(__dirname, "../../lib/vscode/out/vs/server/fork"), [], {
-      env: {
-        ...process.env,
-        CODE_SERVER_PARENT_PID: process.pid.toString(),
-      },
-    })
-    vscode.once("message", (message: any) => {
-      logger.debug("Got message from VS Code", field("message", message))
-      if (message.type !== "ready") {
-        logger.error("Unexpected response waiting for ready response")
-        process.exit(1)
+    return
   }
-      const send: CliMessage = { type: "cli", args }
-      vscode.send(send)
-    })
-    vscode.once("error", (error) => {
-      logger.error(error.message)
-      process.exit(1)
-    })
-    vscode.on("exit", (code) => process.exit(code || 0))
-  } else if (process.env.VSCODE_IPC_HOOK_CLI) {
-    const pipeArgs: OpenCommandPipeArgs = {
-      type: "open",
-      folderURIs: [],
-      forceReuseWindow: args["reuse-window"],
-      forceNewWindow: args["new-window"],
+
+  if (shouldRunVsCodeCli(args)) {
+    return runVsCodeCli(args)
   }
-    const isDir = async (path: string): Promise<boolean> => {
-      try {
-        const st = await fs.stat(path)
-        return st.isDirectory()
-      } catch (error) {
-        return false
-      }
-    }
-    for (let i = 0; i < args._.length; i++) {
-      const fp = path.resolve(args._[i])
-      if (await isDir(fp)) {
-        pipeArgs.folderURIs.push(fp)
-      } else {
-        if (!pipeArgs.fileURIs) {
-          pipeArgs.fileURIs = []
-        }
-        pipeArgs.fileURIs.push(fp)
-      }
-    }
-    if (pipeArgs.forceNewWindow && pipeArgs.fileURIs && pipeArgs.fileURIs.length > 0) {
-      logger.error("new-window can only be used with folder paths")
-      process.exit(1)
-    }
-    if (pipeArgs.folderURIs.length === 0 && (!pipeArgs.fileURIs || pipeArgs.fileURIs.length === 0)) {
-      logger.error("Please specify at least one file or folder argument")
-      process.exit(1)
-    }
-    const vscode = http.request(
-      {
-        path: "/",
-        method: "POST",
-        socketPath: process.env["VSCODE_IPC_HOOK_CLI"],
-      },
-      (res) => {
-        res.on("data", (message) => {
-          logger.debug("Got message from VS Code", field("message", message.toString()))
-        })
-      },
-    )
-    vscode.on("error", (err) => {
-      logger.debug("Got error from VS Code", field("error", err))
-    })
-    vscode.write(JSON.stringify(pipeArgs))
-    vscode.end()
-  } else {
-    wrap(() => main(args, configArgs))
+
+  const socketPath = await shouldOpenInExistingInstance(cliArgs)
+  if (socketPath) {
+    return openInExistingInstance(args, socketPath)
   }
+
+  const wrapper = new WrapperProcess(require("../../package.json").version)
+  return wrapper.start()
 }
 
-entry()
+entry().catch((error) => {
+  logger.error(error.message)
+  ipcMain.exit(error)
+})

src/node/wrapper.ts

@@ -32,19 +32,13 @@ export class IpcMain {
   public readonly onMessage = this._onMessage.event
   private readonly _onDispose = new Emitter<NodeJS.Signals | undefined>()
   public readonly onDispose = this._onDispose.event
-  public readonly processExit: (code?: number) => never
+  public readonly processExit: (code?: number) => never = process.exit
 
-  public constructor(public readonly parentPid?: number) {
+  public constructor(private readonly parentPid?: number) {
     process.on("SIGINT", () => this._onDispose.emit("SIGINT"))
     process.on("SIGTERM", () => this._onDispose.emit("SIGTERM"))
     process.on("exit", () => this._onDispose.emit(undefined))
 
-    // Ensure we control when the process exits.
-    this.processExit = process.exit
-    process.exit = function (code?: number) {
-      logger.warn(`process.exit() was prevented: ${code || "unknown code"}.`)
-    } as (code?: number) => never
-
     this.onDispose((signal) => {
       // Remove listeners to avoid possibly triggering disposal again.
       process.removeAllListeners()
@@ -71,6 +65,19 @@ export class IpcMain {
     }
   }
 
+  /**
+   * Ensure we control when the process exits.
+   */
+  public preventExit(): void {
+    process.exit = function (code?: number) {
+      logger.warn(`process.exit() was prevented: ${code || "unknown code"}.`)
+    } as (code?: number) => never
+  }
+
+  public get isChild(): boolean {
+    return typeof this.parentPid !== "undefined"
+  }
+
   public exit(error?: number | ProcessError): never {
     if (error && typeof error !== "number") {
       this.processExit(typeof error.code === "number" ? error.code : 1)
@@ -127,17 +134,12 @@ export class IpcMain {
   }
 }
 
-let _ipcMain: IpcMain
-export const ipcMain = (): IpcMain => {
-  if (!_ipcMain) {
-    _ipcMain = new IpcMain(
-      typeof process.env.CODE_SERVER_PARENT_PID !== "undefined"
-        ? parseInt(process.env.CODE_SERVER_PARENT_PID)
-        : undefined,
-    )
-  }
-  return _ipcMain
-}
+/**
+ * Channel for communication between the child and parent processes.
+ */
+export const ipcMain = new IpcMain(
+  typeof process.env.CODE_SERVER_PARENT_PID !== "undefined" ? parseInt(process.env.CODE_SERVER_PARENT_PID) : undefined,
+)
 
 export interface WrapperOptions {
   maxMemory?: number
@@ -162,14 +164,11 @@ export class WrapperProcess {
     this.logStdoutStream = rfs.createStream(path.join(paths.data, "coder-logs", "code-server-stdout.log"), opts)
     this.logStderrStream = rfs.createStream(path.join(paths.data, "coder-logs", "code-server-stderr.log"), opts)
 
-    ipcMain().onDispose(() => {
-      if (this.process) {
-        this.process.removeAllListeners()
-        this.process.kill()
-      }
+    ipcMain.onDispose(() => {
+      this.disposeChild()
     })
 
-    ipcMain().onMessage((message) => {
+    ipcMain.onMessage((message) => {
       switch (message.type) {
         case "relaunch":
           logger.info(`Relaunching: ${this.currentVersion} -> ${message.version}`)
@@ -181,28 +180,35 @@ export class WrapperProcess {
           break
       }
     })
+  }
 
+  private disposeChild(): void {
+    this.started = undefined
+    if (this.process) {
+      this.process.removeAllListeners()
+      this.process.kill()
+    }
+  }
+
+  private async relaunch(): Promise<void> {
+    this.disposeChild()
+    try {
+      await this.start()
+    } catch (error) {
+      logger.error(error.message)
+      ipcMain.exit(typeof error.code === "number" ? error.code : 1)
+    }
+  }
+
+  public start(): Promise<void> {
+    // If we have a process then we've already bound this.
+    if (!this.process) {
       process.on("SIGUSR1", async () => {
         logger.info("Received SIGUSR1; hotswapping")
         this.relaunch()
       })
     }
 
-  private async relaunch(): Promise<void> {
-    this.started = undefined
-    if (this.process) {
-      this.process.removeAllListeners()
-      this.process.kill()
-    }
-    try {
-      await this.start()
-    } catch (error) {
-      logger.error(error.message)
-      ipcMain().exit(typeof error.code === "number" ? error.code : 1)
-    }
-  }
-
-  public start(): Promise<void> {
     if (!this.started) {
       this.started = this.spawn().then((child) => {
         // Log both to stdout and to the log directory.
@@ -215,12 +221,10 @@ export class WrapperProcess {
           child.stderr.pipe(process.stderr)
         }
         logger.debug(`spawned inner process ${child.pid}`)
-        ipcMain()
-          .handshake(child)
-          .then(() => {
+        ipcMain.handshake(child).then(() => {
           child.once("exit", (code) => {
             logger.debug(`inner process ${child.pid} exited unexpectedly`)
-              ipcMain().exit(code || 0)
+            ipcMain.exit(code || 0)
           })
         })
         this.process = child
@@ -251,7 +255,7 @@ export class WrapperProcess {
 // It's possible that the pipe has closed (for example if you run code-server
 // --version | head -1). Assume that means we're done.
 if (!process.stdout.isTTY) {
-  process.stdout.on("error", () => ipcMain().exit())
+  process.stdout.on("error", () => ipcMain.exit())
 }
 
 // Don't let uncaught exceptions crash the process.
@@ -261,21 +265,3 @@ process.on("uncaughtException", (error) => {
     logger.error(error.stack)
   }
 })
-
-export const wrap = (fn: () => Promise<void>): void => {
-  if (ipcMain().parentPid) {
-    ipcMain()
-      .handshake()
-      .then(() => fn())
-      .catch((error: ProcessError): void => {
-        logger.error(error.message)
-        ipcMain().exit(error)
-      })
-  } else {
-    const wrapper = new WrapperProcess(require("../../package.json").version)
-    wrapper.start().catch((error) => {
-      logger.error(error.message)
-      ipcMain().exit(error)
-    })
-  }
-}