Set session socket into environment variable (#6282)

* Avoid spawning code-server with --reuse-window and --new-window

These flags mean the user explicitly wants to open in an existing
instance so if the socket is down it should error rather than try to
spawn code-server normally.

* Set session socket into environment variable

While I was at it I added a CLI flag to override the default.  I also
swapped the default to --user-data-dir.

The value is set on an environment variable so it can be used by the
extension host similar to VSCODE_IPC_HOOK_CLI.

* Add e2e test for opening files externally

src/node/app.ts

@@ -9,7 +9,7 @@ import * as util from "../common/util"
 import { DefaultedArgs } from "./cli"
 import { disposer } from "./http"
 import { isNodeJSErrnoException } from "./util"
-import { DEFAULT_SOCKET_PATH, EditorSessionManager, makeEditorSessionManagerServer } from "./vscodeSocket"
+import { EditorSessionManager, makeEditorSessionManagerServer } from "./vscodeSocket"
 import { handleUpgrade } from "./wsRouter"
 
 type SocketOptions = { socket: string; "socket-mode"?: string }
@@ -88,7 +88,7 @@ export const createApp = async (args: DefaultedArgs): Promise<App> => {
   handleUpgrade(wsRouter, server)
 
   const editorSessionManager = new EditorSessionManager()
-  const editorSessionManagerServer = await makeEditorSessionManagerServer(DEFAULT_SOCKET_PATH, editorSessionManager)
+  const editorSessionManagerServer = await makeEditorSessionManagerServer(args["session-socket"], editorSessionManager)
   const disposeEditorSessionManagerServer = disposer(editorSessionManagerServer)
 
   const dispose = async () => {

src/node/cli.ts

@@ -4,7 +4,7 @@ import { load } from "js-yaml"
 import * as os from "os"
 import * as path from "path"
 import { generateCertificate, generatePassword, humanPath, paths, splitOnFirstEquals } from "./util"
-import { DEFAULT_SOCKET_PATH, EditorSessionManagerClient } from "./vscodeSocket"
+import { EditorSessionManagerClient } from "./vscodeSocket"
 
 export enum Feature {
   // No current experimental features!
@@ -51,6 +51,7 @@ export interface UserProvidedCodeArgs {
   "disable-file-downloads"?: boolean
   "disable-workspace-trust"?: boolean
   "disable-getting-started-override"?: boolean
+  "session-socket"?: string
 }
 
 /**
@@ -160,6 +161,9 @@ export const options: Options<Required<UserProvidedArgs>> = {
       "Disable update check. Without this flag, code-server checks every 6 hours against the latest github release and \n" +
       "then notifies you once every week that a new release is available.",
   },
+  "session-socket": {
+    type: "string",
+  },
   "disable-file-downloads": {
     type: "boolean",
     description:
@@ -459,6 +463,7 @@ export interface DefaultedArgs extends ConfigArgs {
   usingEnvHashedPassword: boolean
   "extensions-dir": string
   "user-data-dir": string
+  "session-socket": string
   /* Positional arguments. */
   _: string[]
 }
@@ -479,6 +484,11 @@ export async function setDefaults(cliArgs: UserProvidedArgs, configArgs?: Config
     args["extensions-dir"] = path.join(args["user-data-dir"], "extensions")
   }
 
+  if (!args["session-socket"]) {
+    args["session-socket"] = path.join(args["user-data-dir"], "code-server-ipc.sock")
+  }
+  process.env.CODE_SERVER_SESSION_SOCKET = args["session-socket"]
+
   // --verbose takes priority over --log and --log takes priority over the
   // environment variable.
   if (args.verbose) {
@@ -739,7 +749,10 @@ function bindAddrFromAllSources(...argsConfig: UserProvidedArgs[]): Addr {
  * 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: UserProvidedArgs): Promise<string | undefined> => {
+export const shouldOpenInExistingInstance = async (
+  args: UserProvidedArgs,
+  sessionSocket: string,
+): Promise<string | undefined> => {
   // Always use the existing instance if we're running from VS Code's terminal.
   if (process.env.VSCODE_IPC_HOOK_CLI) {
     logger.debug("Found VSCODE_IPC_HOOK_CLI")
@@ -747,21 +760,22 @@ export const shouldOpenInExistingInstance = async (args: UserProvidedArgs): Prom
   }
 
   const paths = getResolvedPathsFromArgs(args)
-  const client = new EditorSessionManagerClient(DEFAULT_SOCKET_PATH)
-
-  // If we can't connect to the socket then there's no existing instance.
-  if (!(await client.canConnect())) {
-    return undefined
-  }
+  const client = new EditorSessionManagerClient(sessionSocket)
 
   // If these flags are set then assume the user is trying to open in an
-  // existing instance since these flags have no effect otherwise.
+  // existing instance since these flags have no effect otherwise.  That means
+  // if there is no existing instance we should error rather than falling back
+  // to spawning code-server normally.
   const openInFlagCount = ["reuse-window", "new-window"].reduce((prev, cur) => {
     return args[cur as keyof UserProvidedArgs] ? prev + 1 : prev
   }, 0)
   if (openInFlagCount > 0) {
     logger.debug("Found --reuse-window or --new-window")
-    return await client.getConnectedSocketPath(paths[0])
+    const socketPath = await client.getConnectedSocketPath(paths[0])
+    if (!socketPath) {
+      throw new Error(`No opened code-server instances found to handle ${paths[0]}`)
+    }
+    return socketPath
   }
 
   // It's possible the user is trying to spawn another instance of code-server.
@@ -769,7 +783,11 @@ export const shouldOpenInExistingInstance = async (args: UserProvidedArgs): Prom
   //    code-server is invoked exactly like this: `code-server my-file`).
   // 2. That a file or directory was passed.
   // 3. That the socket is active.
+  // 4. That an instance exists to handle the path (implied by #3).
   if (Object.keys(args).length === 1 && typeof args._ !== "undefined" && args._.length > 0) {
+    if (!(await client.canConnect())) {
+      return undefined
+    }
     const socketPath = await client.getConnectedSocketPath(paths[0])
     if (socketPath) {
       logger.debug("Found existing code-server socket")

src/node/entry.ts

@@ -51,7 +51,7 @@ async function entry(): Promise<void> {
     return runCodeCli(args)
   }
 
-  const socketPath = await shouldOpenInExistingInstance(cliArgs)
+  const socketPath = await shouldOpenInExistingInstance(cliArgs, args["session-socket"])
   if (socketPath) {
     logger.debug("Trying to open in existing instance")
     return openInExistingInstance(args, socketPath)

src/node/vscodeSocket.ts

@@ -4,10 +4,7 @@ import * as http from "http"
 import * as path from "path"
 import { HttpCode } from "../common/http"
 import { listen } from "./app"
-import { canConnect, paths } from "./util"
-
-// Socket path of the daemonized code-server instance.
-export const DEFAULT_SOCKET_PATH = path.join(paths.data, `code-server-ipc.sock`)
+import { canConnect } from "./util"
 
 export interface EditorSessionEntry {
   workspace: {