migrate-to-v2: enter troubleshooting on failed migration. theming(?!)

internal/command/migrate_to_v2/migrate_to_v2.go

@@ -426,9 +426,39 @@ func (m *v2PlatformMigrator) Migrate(ctx context.Context) (err error) {
 				header = "(!) An error has occurred. Attempting to rollback changes..."
 			}
 			fmt.Fprintf(m.io.ErrOut, "failed while migrating: %v\n", err)
-			recoveryBlock := render.NewTextBlock(ctx, header)
-			if recoveryErr := m.rollback(ctx, recoveryBlock); recoveryErr != nil {
-				fmt.Fprintf(m.io.ErrOut, "failed while rolling back application: %v\n", recoveryErr)
+
+			enterTroubleshooting := false
+			if !flag.GetYes(ctx) && err != abortedErr && m.io.IsInteractive() {
+				askErr := survey.AskOne(&survey.Confirm{
+					Message: "Would you like to enter interactive troubleshooting mode? If not, the migration will be rolled back.",
+					Default: true,
+				}, &enterTroubleshooting)
+				if askErr != nil {
+					enterTroubleshooting = false
+				}
+			}
+
+			if enterTroubleshooting {
+
+				migrateErr := func() error {
+					t, err := newTroubleshooter(ctx, m.appCompact.Name)
+					if err != nil {
+						return err
+					}
+
+					return t.run(ctx)
+				}()
+				if migrateErr != nil {
+					fmt.Fprintf(m.io.ErrOut, "failed while troubleshooting: %v\n", err)
+				} else {
+					err = nil // Printing an error message below a successful troubleshooting run is confusing
+				}
+
+			} else {
+				recoveryBlock := render.NewTextBlock(ctx, header)
+				if recoveryErr := m.rollback(ctx, recoveryBlock); recoveryErr != nil {
+					fmt.Fprintf(m.io.ErrOut, "failed while rolling back application: %v\n", recoveryErr)
+				}
 			}
 		}
 	}()

internal/command/migrate_to_v2/troubleshoot.go

@@ -24,6 +24,26 @@ import (
 	"github.com/superfly/flyctl/iostreams"
 )
 
+const (
+	yellowBrickRoad = `
+Oops! We ran into issues migrating your app.
+We're constantly working to improve the migration and squash bugs, but for
+now please let this debug wizard guide you down a yellow brick road
+of potential solutions...
+               ,,,,,                    
+       ,,.,,,,,,,,, .                   
+   .,,,,,,,                             
+  ,,,,,,,,,.,,                          
+     ,,,,,,,,,,,,,,,,,,,                
+         ,,,,,,,,,,,,,,,,,,,,           
+            ,,,,,,,,,,,,,,,,,,,,,       
+           ,,,,,,,,,,,,,,,,,,,,,,,      
+        ,,,,,,,,,,,,,,,,,,,,,,,,,,,,.   
+   , ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
+
+`
+)
+
 func newTroubleshoot() *cobra.Command {
 	const (
 		usage = `troubleshoot`
@@ -43,14 +63,18 @@ func newTroubleshoot() *cobra.Command {
 	return cmd
 }
 
-func runTroubleshoot(ctx context.Context) error {
+func runTroubleshoot(ctx context.Context) (err error) {
 	var (
-		appName = appconfig.NameFromContext(ctx)
-
+		appName     = appconfig.NameFromContext(ctx)
 		flapsClient *flaps.Client
-		err         error
 	)
 
+	defer func() {
+		if err != nil {
+			err = wrapTroubleshootingErrWithSuggestions(err)
+		}
+	}()
+
 	flapsClient, err = flaps.NewFromAppName(ctx, appName)
 	if err != nil {
 		return fmt.Errorf("could not create flaps client: %w", err)
@@ -66,6 +90,10 @@ func runTroubleshoot(ctx context.Context) error {
 	return t.run(ctx)
 }
 
+func wrapTroubleshootingErrWithSuggestions(err error) error {
+	return fmt.Errorf("%w\nplease try running `fly migrate-to-v2 troubleshoot` later, or contact hello@fly.io\n", err)
+}
+
 type troubleshooter struct {
 	app      *api.AppCompact
 	machines []*api.Machine
@@ -160,14 +188,33 @@ func (t *troubleshooter) hasMigrated(ctx context.Context) bool {
 func (t *troubleshooter) run(ctx context.Context) error {
 	io := iostreams.FromContext(ctx)
 
+	if t.app.PlatformVersion == appconfig.MachinesPlatform && len(t.allocs) == 0 {
+
+		fmt.Fprintf(io.Out, "No issues detected.\n")
+	}
+
+	// From here on out we know that we're either
+	//   * not on the machines platform, or
+	//   * we have at least one nomad alloc
+	// (meaning: we've got issues)
+
+	fmt.Fprint(io.Out, yellowBrickRoad)
+
 	if t.app.PlatformVersion != appconfig.MachinesPlatform {
 		err := t.unsuspend(ctx)
 		if err != nil {
 			return fmt.Errorf("could not unsuspend app: %w", err)
 		}
 	}
 
-	if t.app.PlatformVersion == appconfig.DetachedPlatform {
+	switch t.app.PlatformVersion {
+	case appconfig.NomadPlatform:
+		// Already handled in newTroubleshooter by the hasMigrated check
+		return nil
+	case appconfig.MachinesPlatform:
+		fmt.Fprintf(io.Out, "Detected Nomad VMs running on V2 app, cleaning up.\n")
+		return t.cleanupNomadSwitchToMachines(ctx)
+	case appconfig.DetachedPlatform:
 		fmt.Fprintf(io.Out, `The app's platform version is 'detached'
 This means that the app is stuck in a half-migrated state, and wasn't able to
 be fully recovered during the migration error rollback process.
@@ -178,16 +225,7 @@ Please use these tools to troubleshoot and attempt to repair the app.
 		return t.detachedInteractiveTroubleshoot(ctx)
 	}
 
-	if t.app.PlatformVersion == appconfig.MachinesPlatform {
-		if len(t.allocs) != 0 {
-			fmt.Fprintf(io.Out, "Detected Nomad VMs running on V2 app, cleaning up.\n")
-			return t.cleanupNomadSwitchToMachines(ctx)
-		}
-	}
-
-	fmt.Fprintf(io.Out, "No issues detected.\n")
-
-	return nil
+	return fmt.Errorf("unknown platform version: %s", t.app.PlatformVersion)
 }
 
 const timedOutErr = "timed out"
@@ -355,6 +393,11 @@ func (t *troubleshooter) detachedInteractiveTroubleshoot(ctx context.Context) er
 		return t.setPlatformVersion(ctx, appconfig.MachinesPlatform)
 	}
 
+	if !io.IsInteractive() {
+		fmt.Fprintf(io.Out, "Troubleshooting mode is intended for interactive use.\nOutput of autodiagnose:\n%s\n", t.detachedAutodiagnose(ctx))
+		return nil
+	}
+
 	const (
 		Autodiagnose            = "Autodiagnose issues"
 		PrintNomad              = "List Nomad VMs"