cmd/tsconnect: output errors to the JS console too

mihaip · mihaip · commit 27f36f77c364 · 2022-08-30T10:46:44.000-07:00
We were just outputting them to the terminal, but that's hard to debug
because we immediately tear down the terminal when getting an error.

Signed-off-by: Mihai Parparita &lt;mihai@tailscale.com&gt;
diff --git a/cmd/tsconnect/src/lib/ssh.ts b/cmd/tsconnect/src/lib/ssh.ts
@@ -27,26 +27,39 @@ export function runSSHSession(
 
   term.focus()
 
-  const sshSession = ipn.ssh(def.hostname, def.username, {
-    writeFn: (input) => term.write(input),
-    setReadFn: (hook) => (onDataHook = hook),
+  let resizeObserver: ResizeObserver | undefined
+  let handleBeforeUnload: ((e: BeforeUnloadEvent) => void) | undefined
+
+  const sshSession = ipn.ssh(def.hostname + "2", def.username, {
+    writeFn(input) {
+      term.write(input)
+    },
+    writeErrorFn(err) {
+      console.error(err)
+      term.write(err)
+    },
+    setReadFn(hook) {
+      onDataHook = hook
+    },
     rows: term.rows,
     cols: term.cols,
-    onDone: () => {
-      resizeObserver.disconnect()
+    onDone() {
+      resizeObserver?.disconnect()
       term.dispose()
-      window.removeEventListener("beforeunload", handleBeforeUnload)
+      if (handleBeforeUnload) {
+        window.removeEventListener("beforeunload", handleBeforeUnload)
+      }
       onDone()
     },
   })
 
   // Make terminal and SSH session track the size of the containing DOM node.
-  const resizeObserver = new ResizeObserver(() => fitAddon.fit())
+  resizeObserver = new ResizeObserver(() => fitAddon.fit())
   resizeObserver.observe(termContainerNode)
   term.onResize(({ rows, cols }) => sshSession.resize(rows, cols))
 
   // Close the session if the user closes the window without an explicit
   // exit.
-  const handleBeforeUnload = () => sshSession.close()
+  handleBeforeUnload = () => sshSession.close()
   window.addEventListener("beforeunload", handleBeforeUnload)
 }
diff --git a/cmd/tsconnect/src/types/wasm_js.d.ts b/cmd/tsconnect/src/types/wasm_js.d.ts
@@ -19,6 +19,7 @@ declare global {
       username: string,
       termConfig: {
         writeFn: (data: string) => void
+        writeErrorFn: (err: string) => void
         setReadFn: (readFn: (data: string) => void) => void
         rows: number
         cols: number
diff --git a/cmd/tsconnect/wasm/wasm_js.go b/cmd/tsconnect/wasm/wasm_js.go
@@ -347,6 +347,7 @@ type jsSSHSession struct {
 
 func (s *jsSSHSession) Run() {
 	writeFn := s.termConfig.Get("writeFn")
+	writeErrorFn := s.termConfig.Get("writeErrorFn")
 	setReadFn := s.termConfig.Get("setReadFn")
 	rows := s.termConfig.Get("rows").Int()
 	cols := s.termConfig.Get("cols").Int()
@@ -357,7 +358,7 @@ func (s *jsSSHSession) Run() {
 		writeFn.Invoke(s)
 	}
 	writeError := func(label string, err error) {
-		write(fmt.Sprintf("%s Error: %v\r\n", label, err))
+		writeErrorFn.Invoke(fmt.Sprintf("%s Error: %v\r\n", label, err))
 	}
 
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)

Original file line number	Diff line number	Diff line change
`@@ -347,6 +347,7 @@ type jsSSHSession struct {`
`347`	`347`
`348`	`348`	`func (s *jsSSHSession) Run() {`
`349`	`349`	`writeFn := s.termConfig.Get("writeFn")`
	`350`	`+ writeErrorFn := s.termConfig.Get("writeErrorFn")`
`350`	`351`	`setReadFn := s.termConfig.Get("setReadFn")`
`351`	`352`	`rows := s.termConfig.Get("rows").Int()`
`352`	`353`	`cols := s.termConfig.Get("cols").Int()`
`@@ -357,7 +358,7 @@ func (s *jsSSHSession) Run() {`
`357`	`358`	`writeFn.Invoke(s)`
`358`	`359`	`}`
`359`	`360`	`writeError := func(label string, err error) {`
`360`		`- write(fmt.Sprintf("%s Error: %v\r\n", label, err))`
	`361`	`+ writeErrorFn.Invoke(fmt.Sprintf("%s Error: %v\r\n", label, err))`
`361`	`362`	`}`
`362`	`363`
`363`	`364`	`ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)`