Preserve stderr color output when redirecting stdout (#65)

Author: murrayju

internal/tiger/cmd/config.go

@@ -206,6 +206,9 @@ func outputTable(w io.Writer, cfg *config.ConfigOutput) error {
 	if cfg.GatewayURL != nil {
 		table.Append("gateway_url", *cfg.GatewayURL)
 	}
+	if cfg.Color != nil {
+		table.Append("color", fmt.Sprintf("%t", *cfg.Color))
+	}
 	if cfg.Output != nil {
 		table.Append("output", *cfg.Output)
 	}

internal/tiger/cmd/config_test.go

@@ -143,6 +143,7 @@ version_check_last_time: ` + now.Format(time.RFC3339) + "\n"
 		"docs_mcp_url":            "https://mcp.tigerdata.com/docs",
 		"project_id":              "json-project",
 		"service_id":              "",
+		"color":                   true,
 		"output":                  "json",
 		"analytics":               true,
 		"password_storage":        "none",
@@ -203,6 +204,7 @@ version_check_last_time: ` + now.Format(time.RFC3339) + "\n"
 		"docs_mcp_url":            "https://mcp.tigerdata.com/docs",
 		"project_id":              "yaml-project",
 		"service_id":              "",
+		"color":                   true,
 		"output":                  "yaml",
 		"analytics":               false,
 		"password_storage":        "keyring",

internal/tiger/cmd/root.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/fatih/color"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"go.uber.org/zap"
@@ -21,6 +22,7 @@ func buildRootCmd() *cobra.Command {
 	var analytics bool
 	var passwordStorage string
 	var skipUpdateCheck bool
+	var colorFlag bool
 
 	cmd := &cobra.Command{
 		Use:   "tiger",
@@ -50,6 +52,10 @@ tiger auth login
 				zap.Bool("debug", cfg.Debug),
 			)
 
+			if !cfg.Color {
+				color.NoColor = true
+			}
+
 			return nil
 		},
 		PersistentPostRunE: func(cmd *cobra.Command, args []string) error {
@@ -61,7 +67,7 @@ tiger auth login
 			// Skip update check if:
 			// 1. --skip-update-check flag was provided
 			// 2. Running "version --check" (version command handles its own check)
-			isVersionCheck := cmd.Name() == "version" && cmd.Flags().Changed("check")
+			isVersionCheck := cmd.Name() == "version" && cmd.Flag("check").Changed
 			if !skipUpdateCheck && !isVersionCheck {
 				output := cmd.ErrOrStderr()
 				result := version.PerformCheck(cfg, &output, false)
@@ -92,13 +98,15 @@ tiger auth login
 	cmd.PersistentFlags().BoolVar(&analytics, "analytics", true, "enable/disable usage analytics")
 	cmd.PersistentFlags().StringVar(&passwordStorage, "password-storage", config.DefaultPasswordStorage, "password storage method (keyring, pgpass, none)")
 	cmd.PersistentFlags().BoolVar(&skipUpdateCheck, "skip-update-check", false, "skip checking for updates on startup")
+	cmd.PersistentFlags().BoolVar(&colorFlag, "color", true, "enable colored output")
 
 	// Bind flags to viper
 	viper.BindPFlag("debug", cmd.PersistentFlags().Lookup("debug"))
 	viper.BindPFlag("project_id", cmd.PersistentFlags().Lookup("project-id"))
 	viper.BindPFlag("service_id", cmd.PersistentFlags().Lookup("service-id"))
 	viper.BindPFlag("analytics", cmd.PersistentFlags().Lookup("analytics"))
 	viper.BindPFlag("password_storage", cmd.PersistentFlags().Lookup("password-storage"))
+	viper.BindPFlag("color", cmd.PersistentFlags().Lookup("color"))
 
 	// Note: api_url is intentionally not exposed as a CLI flag.
 	// It can be configured via:

internal/tiger/config/config.go

@@ -18,6 +18,7 @@ import (
 type Config struct {
 	APIURL               string        `mapstructure:"api_url" yaml:"api_url"`
 	Analytics            bool          `mapstructure:"analytics" yaml:"analytics"`
+	Color                bool          `mapstructure:"color" yaml:"color"`
 	ConfigDir            string        `mapstructure:"config_dir" yaml:"-"`
 	ConsoleURL           string        `mapstructure:"console_url" yaml:"console_url"`
 	Debug                bool          `mapstructure:"debug" yaml:"debug"`
@@ -31,11 +32,13 @@ type Config struct {
 	ServiceID            string        `mapstructure:"service_id" yaml:"service_id"`
 	VersionCheckInterval time.Duration `mapstructure:"version_check_interval" yaml:"version_check_interval"`
 	VersionCheckLastTime time.Time     `mapstructure:"version_check_last_time" yaml:"version_check_last_time"`
+	viper                *viper.Viper  `mapstructure:"-" yaml:"-"`
 }
 
 type ConfigOutput struct {
 	APIURL               *string        `mapstructure:"api_url" json:"api_url,omitempty" yaml:"api_url,omitempty"`
 	Analytics            *bool          `mapstructure:"analytics" json:"analytics,omitempty" yaml:"analytics,omitempty"`
+	Color                *bool          `mapstructure:"color" json:"color,omitempty" yaml:"color,omitempty"`
 	ConfigDir            *string        `mapstructure:"config_dir" json:"config_dir,omitempty" yaml:"config_dir,omitempty"`
 	ConsoleURL           *string        `mapstructure:"console_url" json:"console_url,omitempty" yaml:"console_url,omitempty"`
 	Debug                *bool          `mapstructure:"debug" json:"debug,omitempty" yaml:"debug,omitempty"`
@@ -52,33 +55,35 @@ type ConfigOutput struct {
 }
 
 const (
+	ConfigFileName              = "config.yaml"
 	DefaultAPIURL               = "https://console.cloud.timescale.com/public/api/v1"
+	DefaultAnalytics            = true
+	DefaultColor                = true
 	DefaultConsoleURL           = "https://console.cloud.timescale.com"
-	DefaultGatewayURL           = "https://console.cloud.timescale.com/api"
+	DefaultDebug                = false
 	DefaultDocsMCP              = true
 	DefaultDocsMCPURL           = "https://mcp.tigerdata.com/docs"
+	DefaultGatewayURL           = "https://console.cloud.timescale.com/api"
 	DefaultOutput               = "table"
-	DefaultAnalytics            = true
 	DefaultPasswordStorage      = "keyring"
-	DefaultDebug                = false
 	DefaultReleasesURL          = "https://cli.tigerdata.com"
 	DefaultVersionCheckInterval = 24 * time.Hour
-	ConfigFileName              = "config.yaml"
 )
 
 var defaultValues = map[string]any{
+	"analytics":               DefaultAnalytics,
 	"api_url":                 DefaultAPIURL,
+	"color":                   DefaultColor,
 	"console_url":             DefaultConsoleURL,
-	"gateway_url":             DefaultGatewayURL,
+	"debug":                   DefaultDebug,
 	"docs_mcp":                DefaultDocsMCP,
 	"docs_mcp_url":            DefaultDocsMCPURL,
-	"project_id":              "",
-	"service_id":              "",
+	"gateway_url":             DefaultGatewayURL,
 	"output":                  DefaultOutput,
-	"analytics":               DefaultAnalytics,
 	"password_storage":        DefaultPasswordStorage,
-	"debug":                   DefaultDebug,
+	"project_id":              "",
 	"releases_url":            DefaultReleasesURL,
+	"service_id":              "",
 	"version_check_interval":  DefaultVersionCheckInterval,
 	"version_check_last_time": time.Time{},
 }
@@ -125,6 +130,7 @@ func SetupViper(configDir string) error {
 func FromViper(v *viper.Viper) (*Config, error) {
 	cfg := &Config{
 		ConfigDir: filepath.Dir(v.ConfigFileUsed()),
+		viper:     v,
 	}
 
 	if err := v.Unmarshal(cfg); err != nil {
@@ -213,7 +219,7 @@ func UseTestConfig(configDir string, values map[string]any) (*Config, error) {
 
 func (c *Config) Set(key, value string) error {
 	// Validate and update the field
-	validated, err := c.updateField(key, value)
+	validated, err := c.UpdateField(key, value)
 	if err != nil {
 		return err
 	}
@@ -244,10 +250,10 @@ func setBool(key, val string) (bool, error) {
 	return b, nil
 }
 
-// updateField updates the field in the Config struct corresponding to the given key.
+// UpdateField updates the field in the Config struct corresponding to the given key.
 // It accepts either a string (from user input) or a typed value (string/bool from defaults).
 // The function validates the value and updates both the struct field and viper state.
-func (c *Config) updateField(key string, value any) (any, error) {
+func (c *Config) UpdateField(key string, value any) (any, error) {
 	var validated any
 
 	switch key {
@@ -315,6 +321,22 @@ func (c *Config) updateField(key string, value any) (any, error) {
 		c.ServiceID = s
 		validated = s
 
+	case "color":
+		switch v := value.(type) {
+		case bool:
+			c.Color = v
+			validated = v
+		case string:
+			b, err := setBool("color", v)
+			if err != nil {
+				return nil, err
+			}
+			c.Color = b
+			validated = b
+		default:
+			return nil, fmt.Errorf("color must be string or bool, got %T", value)
+		}
+
 	case "output":
 		s, ok := value.(string)
 		if !ok {
@@ -433,7 +455,11 @@ func (c *Config) updateField(key string, value any) (any, error) {
 		return nil, fmt.Errorf("unknown configuration key: %s", key)
 	}
 
-	viper.Set(key, validated)
+	if c.viper == nil {
+		viper.Set(key, validated)
+	} else {
+		c.viper.Set(key, validated)
+	}
 	return validated, nil
 }
 
@@ -465,7 +491,7 @@ func (c *Config) Unset(key string) error {
 
 	// Apply the default to the current global viper state
 	if def, ok := defaultValues[key]; ok {
-		if _, err := c.updateField(key, def); err != nil {
+		if _, err := c.UpdateField(key, def); err != nil {
 			return err
 		}
 	}
@@ -497,7 +523,7 @@ func (c *Config) Reset() error {
 		if key == "project_id" {
 			continue
 		}
-		if _, err := c.updateField(key, value); err != nil {
+		if _, err := c.UpdateField(key, value); err != nil {
 			return err
 		}
 	}

internal/tiger/version/check.go

@@ -239,6 +239,12 @@ func PrintUpdateWarning(result *CheckResult, cfg *config.Config, output *io.Writ
 		return
 	}
 
+	// need to set color.NoColor correctly for the `output` (stderr)
+	if cfg.Color && util.IsTerminal(*output) {
+		original := color.NoColor
+		defer func() { color.NoColor = original }()
+		color.NoColor = false
+	}
 	fmt.Fprintf(*output, "\n\n%s %s → %s\nTo upgrade: %s\n",
 		color.YellowString("A new release of tiger-cli is available:"),
 		color.CyanString(result.CurrentVersion),