Add --context flag

CHANGELOG.md

@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- [#215](https://github.com/deviceinsight/kafkactl/pull/215) Add `--context` option to set command's context
 
 ## 5.3.0 - 2024-08-14
 ### Added

cmd/root.go

@@ -3,6 +3,8 @@ package cmd
 import (
 	"fmt"
 
+	"github.com/spf13/viper"
+
 	"github.com/deviceinsight/kafkactl/v5/internal/global"
 
 	"github.com/deviceinsight/kafkactl/v5/cmd/alter"
@@ -54,6 +56,18 @@ func NewKafkactlCommand(streams output.IOStreams) *cobra.Command {
 	rootCmd.PersistentFlags().StringVarP(&globalFlags.ConfigFile, "config-file", "C", "",
 		fmt.Sprintf("config file. default locations: %v", globalConfig.DefaultPaths()))
 	rootCmd.PersistentFlags().BoolVarP(&globalFlags.Verbose, "verbose", "V", false, "verbose output")
+	rootCmd.PersistentFlags().StringVar(&globalFlags.Context, "context", "", "The name of the context to use")
+
+	err := rootCmd.RegisterFlagCompletionFunc("context", func(_ *cobra.Command, _ []string, _ string) ([]string, cobra.ShellCompDirective) {
+		var contexts []string
+		for k := range viper.GetStringMap("contexts") {
+			contexts = append(contexts, k)
+		}
+		return contexts, cobra.ShellCompDirectiveDefault
+	})
+	if err != nil {
+		panic(err)
+	}
 
 	k8s.KafkaCtlVersion = Version
 

internal/global/config.go

@@ -2,6 +2,7 @@ package global
 
 import (
 	"errors"
+	"fmt"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -13,6 +14,7 @@ import (
 
 type Flags struct {
 	ConfigFile string
+	Context    string
 	Verbose    bool
 }
 
@@ -52,6 +54,18 @@ func GetFlags() Flags {
 }
 
 func GetCurrentContext() string {
+	var context = configInstance.Flags().Context
+	if context != "" {
+		contexts := viper.GetStringMap("contexts")
+
+		// check if it is an existing context
+		if _, ok := contexts[context]; !ok {
+			output.Fail(fmt.Errorf("not a valid context: %s", context))
+		}
+
+		return context
+	}
+
 	return configInstance.currentContext()
 }