cmd/tailscale/cli: show nicer status output when logged out

Also nicer output when running "down".

Fixes #1680

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/tailscale/cli/down.go

@@ -8,6 +8,7 @@ import (
 	"context"
 	"fmt"
 	"log"
+	"os"
 	"time"
 
 	"github.com/peterbourgon/ff/v2/ffcli"
@@ -33,10 +34,9 @@ func runDown(ctx context.Context, args []string) error {
 		return fmt.Errorf("error fetching current status: %w", err)
 	}
 	if st.BackendState == "Stopped" {
-		log.Printf("already stopped")
+		fmt.Fprintf(os.Stderr, "Tailscale was already stopped.\n")
 		return nil
 	}
-	log.Printf("was in state %q", st.BackendState)
 
 	c, bc, ctx, cancel := connect(ctx)
 	defer cancel()
@@ -51,7 +51,6 @@ func runDown(ctx context.Context, args []string) error {
 			log.Fatal(*n.ErrMessage)
 		}
 		if n.State != nil {
-			log.Printf("now in state %q", *n.State)
 			if *n.State == ipn.Stopped {
 				cancel()
 			}

cmd/tailscale/cli/status.go

@@ -106,9 +106,24 @@ func runStatus(ctx context.Context, args []string) error {
 		return err
 	}
 
-	if st.BackendState == ipn.Stopped.String() {
+	switch st.BackendState {
+	default:
+		fmt.Fprintf(os.Stderr, "unexpected state: %s\n", st.BackendState)
+		os.Exit(1)
+	case ipn.Stopped.String():
 		fmt.Println("Tailscale is stopped.")
 		os.Exit(1)
+	case ipn.NeedsLogin.String():
+		fmt.Println("Logged out.")
+		if st.AuthURL != "" {
+			fmt.Printf("\nLog in at: %s\n", st.AuthURL)
+		}
+		os.Exit(1)
+	case ipn.NeedsMachineAuth.String():
+		fmt.Println("Machine is not yet authorized by tailnet admin.")
+		os.Exit(1)
+	case ipn.Running.String():
+		// Run below.
 	}
 
 	var buf bytes.Buffer