tsconnect: pass in authkey in dev mode (#5320)

This change allows for an auth key to be specified as a url query param
for use in development mode. If an auth key is specified and valid, it
will authorize the client for use immediately.

Updates #5144

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>

cmd/tsconnect/src/index.ts

@@ -18,10 +18,18 @@ async function main() {
   go.run(wasmInstance.instance).then(() =>
     app.handleGoPanic("Unexpected shutdown")
   )
+
+  const params = new URLSearchParams(window.location.search)
+  const authKey = params.get("authkey") ?? undefined
+
   const ipn = newIPN({
     // Persist IPN state in sessionStorage in development, so that we don't need
     // to re-authorize every time we reload the page.
     stateStorage: DEBUG ? sessionStateStorage : undefined,
+    // authKey allows for an auth key to be
+    // specified as a url param which automatically
+    // authorizes the client for use.
+    authKey: DEBUG ? authKey : undefined,
   })
   app.runWithIPN(ipn)
 }

cmd/tsconnect/src/wasm_js.ts

@@ -47,6 +47,7 @@ declare global {
 
   type IPNConfig = {
     stateStorage?: IPNStateStorage
+    authKey?: string
   }
 
   type IPNCallbacks = {

cmd/tsconnect/wasm/wasm_js.go

@@ -69,6 +69,12 @@ func newIPN(jsConfig js.Value) map[string]any {
 		store = &jsStateStore{jsStateStorage}
 	}
 
+	jsAuthKey := jsConfig.Get("authKey")
+	var authKey string
+	if jsAuthKey.Type() == js.TypeString {
+		authKey = jsAuthKey.String()
+	}
+
 	lpc := getOrCreateLogPolicyConfig(store)
 	c := logtail.Config{
 		Collection: lpc.Collection,
@@ -135,7 +141,7 @@ func newIPN(jsConfig js.Value) map[string]any {
 				})`)
 				return nil
 			}
-			jsIPN.run(args[0])
+			jsIPN.run(args[0], authKey)
 			return nil
 		}),
 		"login": js.FuncOf(func(this js.Value, args []js.Value) interface{} {
@@ -182,7 +188,7 @@ type jsIPN struct {
 	lb     *ipnlocal.LocalBackend
 }
 
-func (i *jsIPN) run(jsCallbacks js.Value) {
+func (i *jsIPN) run(jsCallbacks js.Value, authKey string) {
 	notifyState := func(state ipn.State) {
 		jsCallbacks.Call("notifyState", int(state))
 	}
@@ -253,6 +259,7 @@ func (i *jsIPN) run(jsCallbacks js.Value) {
 				WantRunning:      true,
 				Hostname:         generateHostname(),
 			},
+			AuthKey: authKey,
 		})
 		if err != nil {
 			log.Printf("Start error: %v", err)