Option to launch without creating an app (#3726)

If --no-create is specified, it won't create an app, won't create databases, and won't deploy.

Note: you will still be prompted if you wish to tweak your settings as any changes you make there can potentially change what outputs are generated.  Furthermore, retaining this is useful for exercising the launch UI.  This can be avoided by adding a --yes flag.

internal/command/launch/cmd.go

@@ -106,6 +106,10 @@ func New() (cmd *cobra.Command) {
 			Name:        "yaml",
 			Description: "Generate configuration in YAML format",
 		},
+		flag.Bool{
+			Name:        "no-create",
+			Description: "Do not create an app, only generate configuration files",
+		},
 	)
 
 	return
@@ -187,20 +191,22 @@ func run(ctx context.Context) (err error) {
 
 	var state *launchState = nil
 
-	defer func() {
-		if err != nil {
-			tracing.RecordError(span, err, "launch failed")
-			status.Error = err.Error()
+	if !flag.GetBool(ctx, "no-create") {
+		defer func() {
+			if err != nil {
+				tracing.RecordError(span, err, "launch failed")
+				status.Error = err.Error()
 
-			if state != nil && state.sourceInfo != nil && state.sourceInfo.FailureCallback != nil {
-				err = state.sourceInfo.FailureCallback(err)
+				if state != nil && state.sourceInfo != nil && state.sourceInfo.FailureCallback != nil {
+					err = state.sourceInfo.FailureCallback(err)
+				}
 			}
-		}
 
-		status.TraceID = span.SpanContext().TraceID().String()
-		status.Duration = time.Since(startTime)
-		metrics.LaunchStatus(ctx, status)
-	}()
+			status.TraceID = span.SpanContext().TraceID().String()
+			status.Duration = time.Since(startTime)
+			metrics.LaunchStatus(ctx, status)
+		}()
+	}
 
 	if err := warnLegacyBehavior(ctx); err != nil {
 		return err

internal/command/launch/deploy.go

@@ -27,6 +27,7 @@ func (state *launchState) firstDeploy(ctx context.Context) error {
 	}
 
 	// TODO(Allison): Do we want to make the executive decision to just *always* deploy?
+	// Feedback(Sam): scanners need the abiiity to abort the deploy if they detect a problem
 
 	deployNow := true
 	// deployNow := false
@@ -42,6 +43,10 @@ func (state *launchState) firstDeploy(ctx context.Context) error {
 		// promptForDeploy = false
 	}
 
+	if flag.GetBool(ctx, "no-create") {
+		deployNow = false
+	}
+
 	/*
 		if promptForDeploy {
 			confirm, err := prompt.Confirm(ctx, "Would you like to deploy now?")

internal/command/launch/launch.go

@@ -47,29 +47,33 @@ func (state *launchState) Launch(ctx context.Context) error {
 		state.warnedNoCcHa = true
 	}
 
-	app, err := state.createApp(ctx)
-	if err != nil {
-		return err
-	}
+	if !flag.GetBool(ctx, "no-create") {
+		app, err := state.createApp(ctx)
+		if err != nil {
+			return err
+		}
 
-	fmt.Fprintf(io.Out, "Created app '%s' in organization '%s'\n", app.Name, app.Organization.Slug)
-	fmt.Fprintf(io.Out, "Admin URL: https://fly.io/apps/%s\n", app.Name)
-	fmt.Fprintf(io.Out, "Hostname: %s.fly.dev\n", app.Name)
+		fmt.Fprintf(io.Out, "Created app '%s' in organization '%s'\n", app.Name, app.Organization.Slug)
+		fmt.Fprintf(io.Out, "Admin URL: https://fly.io/apps/%s\n", app.Name)
+		fmt.Fprintf(io.Out, "Hostname: %s.fly.dev\n", app.Name)
+	}
 
 	// TODO: ideally this would be passed as a part of the plan to the Launch UI
 	// and allow choices of what actions are desired to be make there.
 	if state.sourceInfo != nil && state.sourceInfo.GitHubActions.Deploy {
-		state.setupGitHubActions(ctx, app.Name)
+		state.setupGitHubActions(ctx, state.Plan.AppName)
 	}
 
 	if err = state.satisfyScannerBeforeDb(ctx); err != nil {
 		return err
 	}
 	// TODO: Return rich info about provisioned DBs, including things
 	//       like public URLs.
-	err = state.createDatabases(ctx)
-	if err != nil {
-		return err
+
+	if !flag.GetBool(ctx, "no-create") {
+		if err = state.createDatabases(ctx); err != nil {
+			return err
+		}
 	}
 	if err = state.satisfyScannerAfterDb(ctx); err != nil {
 		return err
@@ -84,8 +88,10 @@ func (state *launchState) Launch(ctx context.Context) error {
 	}
 
 	// Sentry
-	if err = state.launchSentry(ctx, app.Name); err != nil {
-		return err
+	if !flag.GetBool(ctx, "no-create") {
+		if err = state.launchSentry(ctx, state.Plan.AppName); err != nil {
+			return err
+		}
 	}
 
 	// Finally write application configuration to fly.toml