add helm sync support

Author: jsbroks

cmd/ctrlc/root/sync/helm/client.go

@@ -0,0 +1,130 @@
+package helm
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/charmbracelet/log"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+)
+
+// getKubeConfig loads Kubernetes configuration and returns both the config and a suggested cluster name.
+// It tries multiple sources in order of precedence:
+// 1. KUBECONFIG environment variable
+// 2. Default location (~/.kube/config)
+// 3. In-cluster config (when running inside a Kubernetes pod)
+//
+// Returns: (*rest.Config, clusterName, error)
+func getKubeConfig() (*rest.Config, string, error) {
+	// Try 1: KUBECONFIG environment variable
+	kubeconfigPath := os.Getenv("KUBECONFIG")
+	if kubeconfigPath != "" {
+		log.Info("Loading kubeconfig from environment variable", "path", kubeconfigPath)
+		config, err := clientcmd.BuildConfigFromFlags("", kubeconfigPath)
+		if err != nil {
+			return nil, "", err
+		}
+		clusterName, err := getCurrentContextName(kubeconfigPath)
+		return config, clusterName, err
+	}
+
+	// Try 2: Default location (~/.kube/config)
+	homeDir, err := os.UserHomeDir()
+	if err == nil {
+		kubeconfigPath = filepath.Join(homeDir, ".kube", "config")
+		if _, err := os.Stat(kubeconfigPath); err == nil {
+			log.Info("Loading kubeconfig from home directory", "path", kubeconfigPath)
+			config, err := clientcmd.BuildConfigFromFlags("", kubeconfigPath)
+			if err != nil {
+				return nil, "", err
+			}
+			clusterName, err := getCurrentContextName(kubeconfigPath)
+			return config, clusterName, err
+		}
+	}
+
+	// Try 3: In-cluster config (running inside a pod)
+	log.Info("Loading in-cluster kubeconfig")
+	config, err := rest.InClusterConfig()
+	if err != nil {
+		return nil, "", err
+	}
+
+	// When running in-cluster, derive name from the namespace
+	clusterName, err := getInClusterName()
+	return config, clusterName, err
+}
+
+// getCurrentContextName extracts the current context name from a kubeconfig file.
+// This is typically a meaningful cluster name like "production-cluster" or "minikube".
+func getCurrentContextName(kubeconfigPath string) (string, error) {
+	kubeconfig, err := clientcmd.LoadFromFile(kubeconfigPath)
+	if err != nil {
+		return "", err
+	}
+	return kubeconfig.CurrentContext, nil
+}
+
+// getInClusterName returns a cluster name when running inside a Kubernetes pod.
+// It reads the pod's namespace as a fallback identifier since there's no kubeconfig.
+func getInClusterName() (string, error) {
+	// When running inside a pod, read the namespace from the service account mount
+	nsBytes, err := os.ReadFile("/var/run/secrets/kubernetes.io/serviceaccount/namespace")
+	if err != nil {
+		// If we can't read the namespace, return a default
+		return "unknown-cluster", nil
+	}
+
+	return string(nsBytes), nil
+}
+
+// getConfigFlags converts a rest.Config into Helm-compatible ConfigFlags.
+// Helm's action package requires genericclioptions.ConfigFlags rather than rest.Config directly.
+func getConfigFlags(config *rest.Config, namespace string) *genericclioptions.ConfigFlags {
+	configFlags := genericclioptions.NewConfigFlags(true)
+	
+	// Set the Kubernetes API server URL
+	if config.Host != "" {
+		host := config.Host
+		configFlags.APIServer = &host
+	}
+	
+	// Set the target namespace (if specified)
+	if namespace != "" {
+		configFlags.Namespace = &namespace
+	}
+	
+	// Set authentication token (if using token-based auth)
+	if config.BearerToken != "" {
+		token := config.BearerToken
+		configFlags.BearerToken = &token
+	}
+	
+	// Set TLS options
+	if config.TLSClientConfig.Insecure {
+		insecure := true
+		configFlags.Insecure = &insecure
+	}
+	
+	if len(config.TLSClientConfig.CAData) > 0 {
+		// CA data is embedded in the config and will be used automatically
+		// We rely on the kubeconfig file being available rather than creating a temp file
+	}
+
+	// Set kubeconfig path (needed by Helm for some operations)
+	kubeconfigPath := os.Getenv("KUBECONFIG")
+	if kubeconfigPath == "" {
+		homeDir, err := os.UserHomeDir()
+		if err == nil {
+			kubeconfigPath = filepath.Join(homeDir, ".kube", "config")
+		}
+	}
+	if kubeconfigPath != "" {
+		configFlags.KubeConfig = &kubeconfigPath
+	}
+
+	return configFlags
+}
+