Enhance command flag handling and completion for cluster and policy creation (#933)

- Refactor createFlags function to return an error for better error handling.
- Add flag completion functions for cluster mode and persistence type.
- Implement disableFileCompletion to prevent default filename completions.
- Register flag completion for mode in NewPolicyCreateCmd.

cli/cmds/cluster_create.go

@@ -70,6 +70,7 @@ func NewClusterCreateCmd(appCtx *AppContext) *cobra.Command {
 	}
 
 	CobraFlagNamespace(appCtx, cmd.Flags())
+
 	createFlags(cmd, createConfig)
 
 	return cmd

cli/cmds/cluster_create_flags.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"time"
 
+	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"k8s.io/apimachinery/pkg/api/resource"
 
@@ -32,6 +33,13 @@ func createFlags(cmd *cobra.Command, cfg *CreateConfig) {
 	cmd.Flags().StringVar(&cfg.policy, "policy", "", "The policy to create the cluster in")
 	cmd.Flags().StringVar(&cfg.customCertsPath, "custom-certs", "", "The path for custom certificate directory")
 	cmd.Flags().DurationVar(&cfg.timeout, "timeout", 3*time.Minute, "The timeout for waiting for the cluster to become ready (e.g., 10s, 5m, 1h).")
+
+	mustRegisterFlagCompletion(cmd, "mode", completeClusterMode)
+	mustRegisterFlagCompletion(cmd, "persistence-type", completePersistenceMode)
+
+	if err := cmd.MarkFlagDirname("custom-certs"); err != nil {
+		logrus.Fatal(err)
+	}
 }
 
 func validateCreateConfig(cfg *CreateConfig) error {

cli/cmds/completion.go

@@ -0,0 +1,68 @@
+package cmds
+
+import (
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+
+	"github.com/rancher/k3k/pkg/apis/k3k.io/v1beta1"
+)
+
+var completeClusterMode = cobra.FixedCompletions(
+	[]string{
+		string(v1beta1.SharedClusterMode),
+		string(v1beta1.VirtualClusterMode),
+	},
+	cobra.ShellCompDirectiveNoFileComp,
+)
+
+var completePersistenceMode = cobra.FixedCompletions(
+	[]string{
+		string(v1beta1.DynamicPersistenceMode),
+		string(v1beta1.EphemeralPersistenceMode),
+	},
+	cobra.ShellCompDirectiveNoFileComp,
+)
+
+// mustRegisterFlagCompletion registers a completion function for a flag and
+// aborts if the flag does not exist. This only fails on programmer error, so
+// there is no reason to bubble it up to the caller.
+func mustRegisterFlagCompletion(cmd *cobra.Command, flagName string, f cobra.CompletionFunc) {
+	if err := cmd.RegisterFlagCompletionFunc(flagName, f); err != nil {
+		logrus.Fatal(err)
+	}
+}
+
+// disableFileCompletion walks the command tree and turns off cobra's default
+// filename completion for both positional arguments and flag values, leaving
+// anything that is explicitly configured (enum completers, MarkFlagFilename,
+// MarkFlagDirname, ValidArgs, bool flags) untouched.
+func disableFileCompletion(cmd *cobra.Command) {
+	if cmd.ValidArgsFunction == nil && len(cmd.ValidArgs) == 0 {
+		cmd.ValidArgsFunction = cobra.NoFileCompletions
+	}
+
+	cmd.Flags().VisitAll(func(f *pflag.Flag) {
+		if f.Value.Type() == "bool" {
+			return
+		}
+
+		if _, ok := cmd.GetFlagCompletionFunc(f.Name); ok {
+			return
+		}
+
+		if _, ok := f.Annotations[cobra.BashCompFilenameExt]; ok {
+			return
+		}
+
+		if _, ok := f.Annotations[cobra.BashCompSubdirsInDir]; ok {
+			return
+		}
+
+		_ = cmd.RegisterFlagCompletionFunc(f.Name, cobra.NoFileCompletions)
+	})
+
+	for _, sub := range cmd.Commands() {
+		disableFileCompletion(sub)
+	}
+}

cli/cmds/policy_create.go

@@ -50,6 +50,8 @@ func NewPolicyCreateCmd(appCtx *AppContext) *cobra.Command {
 	cmd.Flags().StringSliceVar(&config.namespaces, "namespace", []string{}, "The namespaces where to bind the policy")
 	cmd.Flags().BoolVar(&config.overwrite, "overwrite", false, "Overwrite namespace binding of existing policy")
 
+	mustRegisterFlagCompletion(cmd, "mode", completeClusterMode)
+
 	return cmd
 }
 

cli/cmds/root.go

@@ -70,12 +70,18 @@ func NewRootCmd() *cobra.Command {
 	rootCmd.PersistentFlags().StringVar(&appCtx.Kubeconfig, "kubeconfig", "", "kubeconfig path ($HOME/.kube/config or $KUBECONFIG if set)")
 	rootCmd.PersistentFlags().BoolVar(&appCtx.Debug, "debug", false, "Turn on debug logs")
 
+	if err := rootCmd.MarkPersistentFlagFilename("kubeconfig"); err != nil {
+		logrus.Fatal(err)
+	}
+
 	rootCmd.AddCommand(
 		NewClusterCmd(appCtx),
 		NewPolicyCmd(appCtx),
 		NewKubeconfigCmd(appCtx),
 	)
 
+	disableFileCompletion(rootCmd)
+
 	return rootCmd
 }