Cleanup after "Add a foundation for built-in templates" (#707)

## Changes
Add some cleanup based on @pietern's comments on
https://github.com/databricks/cli/pull/685

bundle/config/mutator/process_target_mode.go

@@ -160,7 +160,10 @@ func (m *processTargetMode) Apply(ctx context.Context, b *bundle.Bundle) error {
 		}
 		return transformDevelopmentMode(b)
 	case config.Production:
-		isPrincipal := auth.IsServicePrincipal(ctx, b.WorkspaceClient(), b.Config.Workspace.CurrentUser.Id)
+		isPrincipal, err := auth.IsServicePrincipal(ctx, b.WorkspaceClient(), b.Config.Workspace.CurrentUser.Id)
+		if err != nil {
+			return err
+		}
 		return validateProductionMode(ctx, b, isPrincipal)
 	case "":
 		// No action

cmd/root/bundle.go

@@ -43,7 +43,7 @@ func getTarget(cmd *cobra.Command) (value string) {
 	return target
 }
 
-func GetProfile(cmd *cobra.Command) (value string) {
+func getProfile(cmd *cobra.Command) (value string) {
 	// The command line flag takes precedence.
 	flag := cmd.Flag("profile")
 	if flag != nil {
@@ -70,7 +70,7 @@ func loadBundle(cmd *cobra.Command, args []string, load func(ctx context.Context
 		return nil, nil
 	}
 
-	profile := GetProfile(cmd)
+	profile := getProfile(cmd)
 	if profile != "" {
 		b.Config.Workspace.Profile = profile
 	}

libs/auth/service_principal.go

@@ -4,13 +4,17 @@ import (
 	"context"
 
 	"github.com/databricks/databricks-sdk-go"
+	"github.com/databricks/databricks-sdk-go/apierr"
 )
 
 // Determines whether a given user id is a service principal.
 // This function uses a heuristic: if no user exists with this id, we assume
 // it's a service principal. Unfortunately, the standard service principal API is too
 // slow for our purposes.
-func IsServicePrincipal(ctx context.Context, ws *databricks.WorkspaceClient, userId string) bool {
+func IsServicePrincipal(ctx context.Context, ws *databricks.WorkspaceClient, userId string) (bool, error) {
 	_, err := ws.Users.GetById(ctx, userId)
-	return err != nil
+	if apierr.IsMissing(err) {
+		return true, nil
+	}
+	return false, err
 }

libs/template/helpers.go

@@ -104,7 +104,10 @@ func loadHelpers(ctx context.Context) template.FuncMap {
 					return false, err
 				}
 			}
-			result := auth.IsServicePrincipal(ctx, w, user.Id)
+			result, err := auth.IsServicePrincipal(ctx, w, user.Id)
+			if err != nil {
+				return false, err
+			}
 			is_service_principal = &result
 			return result, nil
 		},

libs/template/materialize.go

@@ -7,6 +7,8 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+
+	"github.com/databricks/cli/libs/cmdio"
 )
 
 const libraryDirName = "library"
@@ -80,7 +82,7 @@ func Materialize(ctx context.Context, configFilePath, templateRoot, outputDir st
 	if err != nil {
 		return err
 	}
-	println("✨ Successfully initialized template")
+	cmdio.LogString(ctx, "✨ Successfully initialized template")
 	return nil
 }