Add service discovery k8s action for backendmanage address

cmd/osmanage/main.go

@@ -80,6 +80,7 @@ func RootCmd() *cobra.Command {
 		k8sActions.UpdateBackendmanageCmd(),
 		k8sActions.UpdateInstanceCmd(),
 		k8sActions.ScaleCmd(),
+		k8sActions.GetServiceAddressCmd(),
 	)
 
 	rootCmd.AddCommand(

internal/k8s/actions/get_service_address.go

@@ -0,0 +1,66 @@
+package actions
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/OpenSlides/openslides-cli/internal/k8s/client"
+	"github.com/OpenSlides/openslides-cli/internal/utils"
+	"github.com/spf13/cobra"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+const (
+	GetServiceAddressHelp      = "Get service ClusterIP:Port address"
+	GetServiceAddressHelpExtra = `Returns the service ClusterIP:Port for the given instance and service name.
+
+Examples:
+  osmanage k8s get-service-address ./my.instance.dir.org backendmanage
+  osmanage k8s get-service-address ./my.instance.dir.org backendmanage --kubeconfig ~/.kube/config`
+)
+
+func GetServiceAddressCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "get-service-address <instance-dir> <service-name>",
+		Short: GetServiceAddressHelp,
+		Long:  GetServiceAddressHelp + "\n\n" + GetServiceAddressHelpExtra,
+		Args:  cobra.ExactArgs(2),
+	}
+
+	kubeconfig := cmd.Flags().String("kubeconfig", "", "Path to kubeconfig file")
+
+	cmd.RunE = func(cmd *cobra.Command, args []string) error {
+		instanceDir := args[0]
+		serviceName := args[1]
+
+		namespace := utils.ExtractNamespace(instanceDir)
+
+		k8sClient, err := client.New(*kubeconfig)
+		if err != nil {
+			return fmt.Errorf("creating k8s client: %w", err)
+		}
+
+		ctx := context.Background()
+		svc, err := k8sClient.Clientset().CoreV1().Services(namespace).Get(ctx, serviceName, metav1.GetOptions{})
+		if err != nil {
+			return fmt.Errorf("getting service %s: %w", serviceName, err)
+		}
+
+		if svc.Spec.ClusterIP == "" {
+			return fmt.Errorf("service %s has no ClusterIP", serviceName)
+		}
+
+		if len(svc.Spec.Ports) == 0 {
+			return fmt.Errorf("service %s has no ports", serviceName)
+		}
+
+		port := svc.Spec.Ports[0].Port
+		address := fmt.Sprintf("%s:%d", svc.Spec.ClusterIP, port)
+
+		fmt.Println(address)
+		return nil
+	}
+
+	return cmd
+}