refactor: Make --context cli flag a global option (#174)

* Make `--context` flag a global option and remove duplication

* Remove unused dns showOptions struct

* First pass of refactoring "active context" determination and validation

* Undo some refactoring in cli.go to keep diff more focused

cmd/uncloud/machine/add.go

@@ -26,7 +26,6 @@ type addOptions struct {
 	noInstall bool
 	publicIP  string
 	sshKey    string
-	context   string
 	version   string
 }
 
@@ -89,10 +88,6 @@ Connection methods:
 		&opts.version, "version", "latest",
 		"Version of the Uncloud daemon to install on the machine.",
 	)
-	cmd.Flags().StringVarP(
-		&opts.context, "context", "c", "",
-		"Name of the cluster context to add the machine to. (default is the current context)",
-	)
 
 	return cmd
 }
@@ -113,7 +108,6 @@ func add(ctx context.Context, uncli *cli.CLI, remoteMachine *cli.RemoteMachine,
 	}
 
 	clusterClient, machineClient, err := uncli.AddMachine(ctx, cli.AddMachineOptions{
-		Context:       opts.context,
 		MachineName:   opts.name,
 		PublicIP:      publicIP,
 		RemoteMachine: remoteMachine,

cmd/uncloud/machine/ls.go

@@ -14,25 +14,20 @@ import (
 )
 
 func NewListCommand() *cobra.Command {
-	var contextName string
 	cmd := &cobra.Command{
 		Use:     "ls",
 		Aliases: []string{"list"},
 		Short:   "List machines in a cluster.",
 		RunE: func(cmd *cobra.Command, args []string) error {
 			uncli := cmd.Context().Value("cli").(*cli.CLI)
-			return list(cmd.Context(), uncli, contextName)
+			return list(cmd.Context(), uncli)
 		},
 	}
-	cmd.Flags().StringVarP(
-		&contextName, "context", "c", "",
-		"Name of the cluster context. (default is the current context)",
-	)
 	return cmd
 }
 
-func list(ctx context.Context, uncli *cli.CLI, clusterName string) error {
-	client, err := uncli.ConnectCluster(ctx, clusterName)
+func list(ctx context.Context, uncli *cli.CLI) error {
+	client, err := uncli.ConnectCluster(ctx)
 	if err != nil {
 		return fmt.Errorf("connect to cluster: %w", err)
 	}

cmd/uncloud/machine/rename.go

@@ -9,7 +9,6 @@ import (
 )
 
 func NewRenameCommand() *cobra.Command {
-	var contextName string
 	cmd := &cobra.Command{
 		Use:   "rename OLD_NAME NEW_NAME",
 		Short: "Rename a machine in the cluster.",
@@ -20,18 +19,14 @@ configuration including network settings, public IP, and cluster membership.`,
 		Args: cobra.ExactArgs(2),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			uncli := cmd.Context().Value("cli").(*cli.CLI)
-			return rename(cmd.Context(), uncli, contextName, args[0], args[1])
+			return rename(cmd.Context(), uncli, args[0], args[1])
 		},
 	}
-	cmd.Flags().StringVarP(
-		&contextName, "context", "c", "",
-		"Name of the cluster context. (default is the current context)",
-	)
 	return cmd
 }
 
-func rename(ctx context.Context, uncli *cli.CLI, contextName, oldName, newName string) error {
-	client, err := uncli.ConnectCluster(ctx, contextName)
+func rename(ctx context.Context, uncli *cli.CLI, oldName, newName string) error {
+	client, err := uncli.ConnectCluster(ctx)
 	if err != nil {
 		return err
 	}

cmd/uncloud/machine/rm.go

@@ -22,7 +22,6 @@ import (
 type removeOptions struct {
 	noReset bool
 	yes     bool
-	context string
 }
 
 func NewRmCommand() *cobra.Command {
@@ -39,8 +38,6 @@ func NewRmCommand() *cobra.Command {
 		},
 	}
 
-	cmd.Flags().StringVarP(&opts.context, "context", "c", "",
-		"Name of the cluster context. (default is the current context)")
 	cmd.Flags().BoolVarP(&opts.yes, "yes", "y", false,
 		"Do not prompt for confirmation before removing the machine.")
 	cmd.Flags().BoolVar(&opts.noReset, "no-reset", false,
@@ -51,7 +48,7 @@ func NewRmCommand() *cobra.Command {
 
 func remove(ctx context.Context, uncli *cli.CLI, nameOrID string, opts removeOptions) error {
 	// TODO: automatically choose a connection to the machine that is not being removed.
-	client, err := uncli.ConnectCluster(ctx, opts.context)
+	client, err := uncli.ConnectCluster(ctx)
 	if err != nil {
 		return fmt.Errorf("connect to cluster: %w", err)
 	}

cmd/uncloud/machine/update.go

@@ -13,7 +13,6 @@ import (
 type updateOptions struct {
 	name     string
 	publicIP string
-	context  string
 }
 
 func NewUpdateCommand() *cobra.Command {
@@ -43,10 +42,6 @@ At least one flag must be specified to perform an update operation.`,
 		&opts.publicIP, "public-ip", "",
 		fmt.Sprintf("Public IP address of the machine for ingress configuration. Use '%s' or '' to remove the public IP.", PublicIPNone),
 	)
-	cmd.Flags().StringVarP(
-		&opts.context, "context", "c", "",
-		"Name of the cluster context. (default is the current context)",
-	)
 
 	return cmd
 }
@@ -57,7 +52,7 @@ func update(ctx context.Context, uncli *cli.CLI, cmd *cobra.Command, opts update
 		return fmt.Errorf("at least one update flag must be specified (--name, --public-ip)")
 	}
 
-	client, err := uncli.ConnectCluster(ctx, opts.context)
+	client, err := uncli.ConnectCluster(ctx)
 	if err != nil {
 		return err
 	}