Replace logging system with slog and tint for structured colored output

- Add logger.go with public Logger variable and InitLogger function
- Replace all fmt.Printf/fmt.Fprintf calls with structured Logger.Info/Logger.Error
- Initialize logger in main function for consistent access across packages
- Keep fmt.Errorf for proper error creation (standard Go practice)
- Add tint dependency for colorized terminal output with timestamps
- Convert user output to structured logging with key-value pairs
- Update info command to use structured logging for plugin details
- Update updateassets command to use structured progress logging
- Update version command to use structured logging
- Update authentication logging in client.go with structured fields
- Update enable/disable commands to use structured logging
- Remove unused fmt imports after conversion

All output now uses slog with tint for beautiful, structured, colorized logging
while maintaining proper error handling with fmt.Errorf for error creation.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Makefile

@@ -136,7 +136,7 @@ verify: clean lint test build ## Verify build (clean, lint, test, build)
 
 # Quick development build
 .PHONY: dev
-dev: fmt lint build ## Quick development build (fmt, lint, build)
+dev: fmt lint snapshot ## Quick development build (fmt, lint, build)
 
 # Check changes target
 .PHONY: check-changes

client.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log"
 	"net"
 	"os"
 	"time"
@@ -22,14 +21,13 @@ func getClient(ctx context.Context) (*model.Client4, error) {
 
 	client, connected := getUnixClient(socketPath)
 	if connected {
-		log.Printf("Connecting using local mode over %s", socketPath)
+		Logger.Info("Connecting using local mode", "socket_path", socketPath)
 
 		return client, nil
 	}
 
 	if os.Getenv("MM_LOCALSOCKETPATH") != "" {
-		log.Printf("No socket found at %s for local mode deployment. "+
-			"Attempting to authenticate with credentials.", socketPath)
+		Logger.Info("No socket found for local mode deployment. Attempting to authenticate with credentials.", "socket_path", socketPath)
 	}
 
 	siteURL := os.Getenv("MM_SERVICESETTINGS_SITEURL")
@@ -44,7 +42,7 @@ func getClient(ctx context.Context) (*model.Client4, error) {
 	client = model.NewAPIv4Client(siteURL)
 
 	if adminToken != "" {
-		log.Printf("Authenticating using token against %s.", siteURL)
+		Logger.Info("Authenticating using token", "site_url", siteURL)
 		client.SetToken(adminToken)
 
 		return client, nil
@@ -52,7 +50,7 @@ func getClient(ctx context.Context) (*model.Client4, error) {
 
 	if adminUsername != "" && adminPassword != "" {
 		client := model.NewAPIv4Client(siteURL)
-		log.Printf("Authenticating as %s against %s.", adminUsername, siteURL)
+		Logger.Info("Authenticating with credentials", "username", adminUsername, "site_url", siteURL)
 		_, _, err := client.Login(ctx, adminUsername, adminPassword)
 		if err != nil {
 			return nil, fmt.Errorf("failed to login as %s: %w", adminUsername, err)

cmd/pluginctl/main.go

@@ -15,6 +15,9 @@ const (
 )
 
 func main() {
+	// Initialize logger
+	pluginctl.InitLogger()
+
 	var pluginPath string
 
 	flag.StringVar(&pluginPath, "plugin-path", "", "Path to plugin directory (overrides PLUGINCTL_PLUGIN_PATH)")
@@ -22,7 +25,7 @@ func main() {
 
 	args := flag.Args()
 	if len(args) == 0 {
-		fmt.Fprintf(os.Stderr, "Error: No command specified\n\n")
+		pluginctl.Logger.Error("No command specified")
 		showUsage()
 		os.Exit(ExitError)
 	}
@@ -34,7 +37,7 @@ func main() {
 	effectivePluginPath := pluginctl.GetEffectivePluginPath(pluginPath)
 
 	if err := runCommand(command, commandArgs, effectivePluginPath); err != nil {
-		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		pluginctl.Logger.Error("Command failed", "error", err)
 		os.Exit(ExitError)
 	}
 }
@@ -68,7 +71,7 @@ func runInfoCommand(args []string, pluginPath string) error {
 
 func runVersionCommand(_ []string) error {
 	version := pluginctl.GetVersion()
-	fmt.Printf("pluginctl version %s\n", version)
+	pluginctl.Logger.Info("pluginctl version", "version", version)
 
 	return nil
 }
@@ -89,7 +92,7 @@ func runUpdateAssetsCommand(args []string, pluginPath string) error {
 }
 
 func showUsage() {
-	fmt.Printf(`pluginctl - Mattermost Plugin Development CLI
+	usageText := `pluginctl - Mattermost Plugin Development CLI
 
 Usage:
   pluginctl [global options] <command> [command options] [arguments...]
@@ -127,5 +130,6 @@ Environment Variables:
 
 For more information about Mattermost plugin development, visit:
 https://developers.mattermost.com/integrate/plugins/
-`)
+`
+	pluginctl.Logger.Info(usageText)
 }

disable.go

@@ -3,7 +3,6 @@ package pluginctl
 import (
 	"context"
 	"fmt"
-	"log"
 
 	"github.com/mattermost/mattermost/server/public/model"
 )
@@ -13,7 +12,7 @@ func RunDisableCommand(args []string, pluginPath string) error {
 }
 
 func disablePlugin(ctx context.Context, client *model.Client4, pluginID string) error {
-	log.Print("Disabling plugin.")
+	Logger.Info("Disabling plugin")
 	_, err := client.DisablePlugin(ctx, pluginID)
 	if err != nil {
 		return fmt.Errorf("failed to disable plugin: %w", err)

enable.go

@@ -3,7 +3,6 @@ package pluginctl
 import (
 	"context"
 	"fmt"
-	"log"
 
 	"github.com/mattermost/mattermost/server/public/model"
 )
@@ -13,7 +12,7 @@ func RunEnableCommand(args []string, pluginPath string) error {
 }
 
 func enablePlugin(ctx context.Context, client *model.Client4, pluginID string) error {
-	log.Print("Enabling plugin.")
+	Logger.Info("Enabling plugin")
 	_, err := client.EnablePlugin(ctx, pluginID)
 	if err != nil {
 		return fmt.Errorf("failed to enable plugin: %w", err)

go.mod

@@ -303,6 +303,7 @@ require (
 	github.com/ldez/tagliatelle v0.5.0 // indirect
 	github.com/leonklingele/grouper v1.1.2 // indirect
 	github.com/letsencrypt/boulder v0.0.0-20250411005613-d800055fe666 // indirect
+	github.com/lmittmann/tint v1.1.2 // indirect
 	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
 	github.com/macabu/inamedparam v0.1.3 // indirect
 	github.com/mailru/easyjson v0.9.0 // indirect

go.sum

@@ -870,6 +870,8 @@ github.com/leonklingele/grouper v1.1.2 h1:o1ARBDLOmmasUaNDesWqWCIFH3u7hoFlM84Yrj
 github.com/leonklingele/grouper v1.1.2/go.mod h1:6D0M/HVkhs2yRKRFZUoGjeDy7EZTfFBE9gl4kjmIGkA=
 github.com/letsencrypt/boulder v0.0.0-20250411005613-d800055fe666 h1:ndfLOJNaxu0fX358UKxtq2bU8IMASWi87Hn0Nv/TIoY=
 github.com/letsencrypt/boulder v0.0.0-20250411005613-d800055fe666/go.mod h1:WGXwLq/jKt0kng727wv6a0h0q7TVC+MwS2S75rcqL+4=
+github.com/lmittmann/tint v1.1.2 h1:2CQzrL6rslrsyjqLDwD11bZ5OpLBPU+g3G/r5LSfS8w=
+github.com/lmittmann/tint v1.1.2/go.mod h1:HIS3gSy7qNwGCj+5oRjAutErFBl4BzdQP6cJZ0NfMwE=
 github.com/lucasb-eyer/go-colorful v1.2.0 h1:1nnpGOrhyZZuNyfu1QjKiUICQ74+3FNCN69Aj6K7nkY=
 github.com/lucasb-eyer/go-colorful v1.2.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/lunixbochs/vtclean v1.0.0/go.mod h1:pHhQNgMf3btfWnGBVipUOjRYhoOsdGqdm/+2c2E2WMI=

info.go

@@ -19,63 +19,58 @@ func InfoCommand() error {
 
 // PrintPluginInfo displays formatted plugin information.
 func PrintPluginInfo(manifest *model.Manifest) error {
-	fmt.Printf("Plugin Information:\n")
-	fmt.Printf("==================\n\n")
+	Logger.Info("Plugin Information:")
+	Logger.Info("==================")
 
 	// Basic plugin info
-	fmt.Printf("ID:              %s\n", manifest.Id)
-	fmt.Printf("Name:            %s\n", manifest.Name)
-	fmt.Printf("Version:         %s\n", manifest.Version)
+	Logger.Info("ID:", "value", manifest.Id)
+	Logger.Info("Name:", "value", manifest.Name)
+	Logger.Info("Version:", "value", manifest.Version)
 
 	// Minimum Mattermost version
 	if manifest.MinServerVersion != "" {
-		fmt.Printf("Min MM Version:  %s\n", manifest.MinServerVersion)
+		Logger.Info("Min MM Version:", "value", manifest.MinServerVersion)
 	} else {
-		fmt.Printf("Min MM Version:  Not specified\n")
+		Logger.Info("Min MM Version:", "value", "Not specified")
 	}
 
 	// Description if available
 	if manifest.Description != "" {
-		fmt.Printf("Description:     %s\n", manifest.Description)
+		Logger.Info("Description:", "value", manifest.Description)
 	}
 
-	fmt.Printf("\nCode Components:\n")
-	fmt.Printf("================\n")
+	Logger.Info("Code Components:")
+	Logger.Info("================")
 
 	// Server code presence
 	if HasServerCode(manifest) {
-		fmt.Printf("Server Code:     Yes\n")
+		Logger.Info("Server Code:", "value", "Yes")
 		if manifest.Server != nil && len(manifest.Server.Executables) > 0 {
-			fmt.Printf("  Executables:   ")
-			first := true
+			var executables []string
 			for platform := range manifest.Server.Executables {
-				if !first {
-					fmt.Printf(", ")
-				}
-				fmt.Printf("%s", platform)
-				first = false
+				executables = append(executables, platform)
 			}
-			fmt.Printf("\n")
+			Logger.Info("Executables:", "platforms", executables)
 		}
 	} else {
-		fmt.Printf("Server Code:     No\n")
+		Logger.Info("Server Code:", "value", "No")
 	}
 
 	// Webapp code presence
 	if HasWebappCode(manifest) {
-		fmt.Printf("Webapp Code:     Yes\n")
+		Logger.Info("Webapp Code:", "value", "Yes")
 		if manifest.Webapp != nil && manifest.Webapp.BundlePath != "" {
-			fmt.Printf("  Bundle Path:   %s\n", manifest.Webapp.BundlePath)
+			Logger.Info("Bundle Path:", "value", manifest.Webapp.BundlePath)
 		}
 	} else {
-		fmt.Printf("Webapp Code:     No\n")
+		Logger.Info("Webapp Code:", "value", "No")
 	}
 
 	// Settings schema
 	if manifest.SettingsSchema != nil {
-		fmt.Printf("Settings Schema: Yes\n")
+		Logger.Info("Settings Schema:", "value", "Yes")
 	} else {
-		fmt.Printf("Settings Schema: No\n")
+		Logger.Info("Settings Schema:", "value", "No")
 	}
 
 	return nil

logger.go

@@ -0,0 +1,37 @@
+package pluginctl
+
+import (
+	"log/slog"
+	"os"
+	"time"
+
+	"github.com/lmittmann/tint"
+)
+
+// Logger is the global logger instance
+var Logger *slog.Logger
+
+// InitLogger initializes the global logger
+func InitLogger() {
+	// Create a tint handler for colorized output
+	handler := tint.NewHandler(os.Stderr, &tint.Options{
+		Level:      slog.LevelInfo,
+		TimeFormat: time.Kitchen,
+		AddSource:  false,
+		NoColor:    false,
+	})
+
+	Logger = slog.New(handler)
+}
+
+// SetLogLevel sets the minimum logging level
+func SetLogLevel(level slog.Level) {
+	handler := tint.NewHandler(os.Stderr, &tint.Options{
+		Level:      level,
+		TimeFormat: time.Kitchen,
+		AddSource:  false,
+		NoColor:    false,
+	})
+
+	Logger = slog.New(handler)
+}

updateassets.go

@@ -18,7 +18,7 @@ func RunUpdateAssetsCommand(args []string, pluginPath string) error {
 		return fmt.Errorf("updateassets command does not accept arguments")
 	}
 
-	fmt.Printf("Updating assets in plugin directory: %s\n", pluginPath)
+	Logger.Info("Updating assets in plugin directory", "path", pluginPath)
 
 	// Load plugin manifest to check for webapp code
 	manifest, err := LoadPluginManifestFromPath(pluginPath)
@@ -82,7 +82,7 @@ func RunUpdateAssetsCommand(args []string, pluginPath string) error {
 			if err := os.WriteFile(targetPath, content, 0644); err != nil {
 				return fmt.Errorf("failed to write file %s: %w", targetPath, err)
 			}
-			fmt.Printf("Updated file: %s\n", relativePath)
+			Logger.Info("Updated file", "path", relativePath)
 			updatedCount++
 		}
 
@@ -93,6 +93,6 @@ func RunUpdateAssetsCommand(args []string, pluginPath string) error {
 		return fmt.Errorf("failed to update assets: %w", err)
 	}
 
-	fmt.Printf("Assets updated successfully! (%d files updated)\n", updatedCount)
+	Logger.Info("Assets updated successfully!", "files_updated", updatedCount)
 	return nil
 }

version.go

@@ -1,14 +1,13 @@
 package pluginctl
 
 import (
-	"fmt"
 	"runtime/debug"
 )
 
 // RunVersionCommand implements the 'version' command functionality.
 func RunVersionCommand(args []string) error {
 	version := GetVersion()
-	fmt.Printf("pluginctl version %s\n", version)
+	Logger.Info("pluginctl version", "version", version)
 
 	return nil
 }