Add cli flag to enable structured logging

cli/cmd/build/build.go

@@ -18,7 +18,7 @@ func BuildCmd(ver version.Version) *cobra.Command {
 		Use:   "build",
 		Short: "Build project without starting web app",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath)
+			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath, local.LogFormatColor)
 			if err != nil {
 				return err
 			}

cli/cmd/initialize/init.go

@@ -40,7 +40,7 @@ func InitCmd(ver version.Version) *cobra.Command {
 			fmt.Println("You can reach us in our Rill Discord server at https://bit.ly/3NSMKdT.")
 			fmt.Println("")
 
-			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath)
+			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath, local.LogFormatColor)
 			if err != nil {
 				return err
 			}

cli/cmd/source/add.go

@@ -40,7 +40,7 @@ func AddCmd(ver version.Version) *cobra.Command {
 				dataPath = relPath
 			}
 
-			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath)
+			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath, local.LogFormatColor)
 			if err != nil {
 				return err
 			}

cli/cmd/source/drop.go

@@ -28,7 +28,7 @@ func DropCmd(ver version.Version) *cobra.Command {
 				return fmt.Errorf("not a valid source name: %s", sourceName)
 			}
 
-			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath)
+			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath, local.LogFormatColor)
 			if err != nil {
 				return err
 			}

cli/cmd/start/start.go

@@ -18,12 +18,18 @@ func StartCmd(ver version.Version) *cobra.Command {
 	var verbose bool
 	var noUI bool
 	var noOpen bool
+	var format string
 
 	startCmd := &cobra.Command{
 		Use:   "start",
 		Short: "Build project and start web app",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath)
+			logFormat, ok := local.ParseLogFormat(format)
+			if !ok {
+				logFormat = local.LogFormatColor
+			}
+
+			app, err := local.NewApp(cmd.Context(), ver, verbose, olapDriver, olapDSN, projectPath, logFormat)
 			if err != nil {
 				return err
 			}
@@ -60,6 +66,7 @@ func StartCmd(ver version.Version) *cobra.Command {
 	startCmd.Flags().IntVar(&grpcPort, "port-grpc", 9010, "Port for gRPC")
 	startCmd.Flags().BoolVar(&noUI, "no-ui", false, "Serve only the backend")
 	startCmd.Flags().BoolVar(&verbose, "verbose", false, "Sets the log level to debug")
+	startCmd.Flags().StringVar(&format, "log-format", "color", "Sets the log format to color/json")
 
 	return startCmd
 }

cli/pkg/local/app.go

@@ -36,6 +36,14 @@ import (
 	_ "github.com/rilldata/rill/runtime/drivers/sqlite"
 )
 
+type LogFormat string
+
+// Default log formats for logger
+const (
+	LogFormatColor = "color"
+	LogFormatJSON  = "json"
+)
+
 // Default instance config on local.
 const (
 	DefaultInstanceID = "default"
@@ -57,12 +65,21 @@ type App struct {
 	ProjectPath string
 }
 
-func NewApp(ctx context.Context, ver version.Version, verbose bool, olapDriver, olapDSN, projectPath string) (*App, error) {
-	// Setup a friendly-looking colored logger
+func NewApp(ctx context.Context, ver version.Version, verbose bool, olapDriver, olapDSN, projectPath string, logFormat LogFormat) (*App, error) {
+	// Setup a friendly-looking colored/json logger
+	var encoder zapcore.Encoder
 	conf := zap.NewDevelopmentEncoderConfig()
 	conf.EncodeLevel = zapcore.CapitalColorLevelEncoder
+
+	switch logFormat {
+	case LogFormatJSON:
+		encoder = zapcore.NewJSONEncoder(conf)
+	case LogFormatColor:
+		encoder = zapcore.NewConsoleEncoder(conf)
+	}
+
 	logger := zap.New(zapcore.NewCore(
-		zapcore.NewConsoleEncoder(conf),
+		encoder,
 		zapcore.AddSync(colorable.NewColorableStdout()),
 		zapcore.DebugLevel,
 	))
@@ -440,3 +457,14 @@ func cors(h http.Handler) http.Handler {
 		h.ServeHTTP(w, r)
 	})
 }
+
+func ParseLogFormat(format string) (LogFormat, bool) {
+	switch format {
+	case "json":
+		return LogFormatJSON, true
+	case "color":
+		return LogFormatColor, true
+	default:
+		return "", false
+	}
+}