feat: enable initial support for logging

Closes #32

Author: manusa

README.md

@@ -128,9 +128,10 @@ npx kubernetes-mcp-server@latest --help
 
 ### Configuration Options
 
-| Option       | Description                                                                              |
-|--------------|------------------------------------------------------------------------------------------|
-| `--sse-port` | Starts the MCP server in Server-Sent Event (SSE) mode and listens on the specified port. |
+| Option        | Description                                                                                                                                                                                                                                                                                   |
+|---------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `--sse-port`  | Starts the MCP server in Server-Sent Event (SSE) mode and listens on the specified port.                                                                                                                                                                                                      |
+| `--log-level` | Sets the logging level (values [from 0-9](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-instrumentation/logging.md)). Similar to [kubectl logging levels](https://kubernetes.io/docs/reference/kubectl/quick-reference/#kubectl-output-verbosity-and-debugging). |
 
 ## 🧑‍💻 Development <a id="development"></a>
 

go.mod

@@ -13,6 +13,7 @@ require (
 	k8s.io/apiextensions-apiserver v0.32.3
 	k8s.io/apimachinery v0.32.3
 	k8s.io/client-go v0.32.3
+	k8s.io/klog/v2 v2.130.1
 	k8s.io/utils v0.0.0-20241104100929-3ea5e8cea738
 	sigs.k8s.io/controller-runtime v0.20.4
 	sigs.k8s.io/controller-runtime/tools/setup-envtest v0.0.0-20250211091558-894df3a7e664
@@ -64,7 +65,6 @@ require (
 	gopkg.in/evanphx/json-patch.v4 v4.12.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
-	k8s.io/klog/v2 v2.130.1 // indirect
 	k8s.io/kube-openapi v0.0.0-20241105132330-32ad38e42d3f // indirect
 	sigs.k8s.io/json v0.0.0-20241010143419-9aa6b5e7a4b3 // indirect
 	sigs.k8s.io/structured-merge-diff/v4 v4.4.2 // indirect

pkg/kubernetes-mcp-server/cmd/root.go

@@ -2,13 +2,18 @@ package cmd
 
 import (
 	"errors"
+	"flag"
 	"fmt"
 	"github.com/manusa/kubernetes-mcp-server/pkg/mcp"
 	"github.com/manusa/kubernetes-mcp-server/pkg/version"
 	"github.com/mark3labs/mcp-go/server"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"golang.org/x/net/context"
+	"k8s.io/klog/v2"
+	"k8s.io/klog/v2/textlogger"
+	"os"
+	"strconv"
 )
 
 var rootCmd = &cobra.Command{
@@ -34,6 +39,7 @@ Kubernetes Model Context Protocol (MCP) server
 
   # TODO: add more examples`,
 	Run: func(cmd *cobra.Command, args []string) {
+		initLogging()
 		if viper.GetBool("version") {
 			fmt.Println(version.Version)
 			return
@@ -47,10 +53,12 @@ Kubernetes Model Context Protocol (MCP) server
 		var sseServer *server.SSEServer
 		if ssePort := viper.GetInt("sse-port"); ssePort > 0 {
 			sseServer = mcpServer.ServeSse(viper.GetString("sse-base-url"))
+			defer func() { _ = sseServer.Shutdown(cmd.Context()) }()
+			klog.V(0).Infof("SSE server starting on port %d", ssePort)
 			if err := sseServer.Start(fmt.Sprintf(":%d", ssePort)); err != nil {
-				panic(err)
+				klog.Errorf("Failed to start SSE server: %s", err)
+				return
 			}
-			defer sseServer.Shutdown(cmd.Context())
 		}
 		if err := mcpServer.ServeStdio(); err != nil && !errors.Is(err, context.Canceled) {
 			panic(err)
@@ -60,6 +68,7 @@ Kubernetes Model Context Protocol (MCP) server
 
 func init() {
 	rootCmd.Flags().BoolP("version", "v", false, "Print version information and quit")
+	rootCmd.Flags().IntP("log-level", "", 0, "Set the log level (from 0 to 9)")
 	rootCmd.Flags().IntP("sse-port", "", 0, "Start a SSE server on the specified port")
 	rootCmd.Flags().StringP("sse-base-url", "", "", "SSE public base URL to use when sending the endpoint message (e.g. https://example.com)")
 	_ = viper.BindPFlags(rootCmd.Flags())
@@ -70,3 +79,13 @@ func Execute() {
 		panic(err)
 	}
 }
+
+func initLogging() {
+	logger := textlogger.NewLogger(textlogger.NewConfig(textlogger.Output(os.Stdout)))
+	klog.SetLoggerWithOptions(logger)
+	flagSet := flag.NewFlagSet("kubernetes-mcp-server", flag.ContinueOnError)
+	klog.InitFlags(flagSet)
+	if logLevel := viper.GetInt("log-level"); logLevel >= 0 {
+		_ = flagSet.Parse([]string{"--v", strconv.Itoa(logLevel)})
+	}
+}