feat: add 'ctx ls' command to list available cluster contexts in config

cmd/uncloud/context/ls.go

@@ -0,0 +1,61 @@
+package context
+
+import (
+	"fmt"
+	"maps"
+	"os"
+	"slices"
+	"text/tabwriter"
+
+	"github.com/psviderski/uncloud/internal/cli"
+	"github.com/spf13/cobra"
+)
+
+func NewListCommand() *cobra.Command {
+	var clusterContext string
+
+	cmd := &cobra.Command{
+		Use:     "list",
+		Aliases: []string{"ls"},
+		Short:   "List available cluster contexts.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			uncli := cmd.Context().Value("cli").(*cli.CLI)
+			return list(uncli)
+		},
+	}
+
+	cmd.Flags().StringVarP(
+		&clusterContext, "context", "c", "",
+		"Name of the cluster context. (default is the current context)",
+	)
+
+	return cmd
+}
+
+func list(uncli *cli.CLI) error {
+	if uncli.Config == nil {
+		return fmt.Errorf("context management is not available: Uncloud configuration file is not being used")
+	}
+
+	if len(uncli.Config.Contexts) == 0 {
+		fmt.Println("No contexts found")
+		return nil
+	}
+
+	contextNames := slices.Sorted(maps.Keys(uncli.Config.Contexts))
+	currentContext := uncli.Config.CurrentContext
+
+	tw := tabwriter.NewWriter(os.Stdout, 0, 0, 3, ' ', 0)
+	fmt.Fprintln(tw, "NAME\tCURRENT\tCONNECTIONS")
+
+	for _, name := range contextNames {
+		current := ""
+		if name == currentContext {
+			current = "*"
+		}
+		connCount := len(uncli.Config.Contexts[name].Connections)
+		fmt.Fprintf(tw, "%s\t%s\t%d\n", name, current, connCount)
+	}
+
+	return tw.Flush()
+}

cmd/uncloud/context/root.go

@@ -0,0 +1,23 @@
+package context
+
+import (
+	"github.com/spf13/cobra"
+)
+
+func NewRootCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:     "context",
+		Aliases: []string{"ctx"},
+		Short:   "Switch between different cluster contexts. Contains subcommands to manage contexts.",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			// TODO
+			return nil
+		},
+	}
+
+	cmd.AddCommand(
+		NewListCommand(),
+	)
+
+	return cmd
+}

cmd/uncloud/main.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/psviderski/uncloud/cmd/uncloud/caddy"
+	cmdcontext "github.com/psviderski/uncloud/cmd/uncloud/context"
 	"github.com/psviderski/uncloud/cmd/uncloud/dns"
 	"github.com/psviderski/uncloud/cmd/uncloud/machine"
 	"github.com/psviderski/uncloud/cmd/uncloud/service"
@@ -67,10 +68,12 @@ func main() {
 	cmd.PersistentFlags().StringVar(&opts.configPath, "uncloud-config", "~/.config/uncloud/config.yaml",
 		"Path to the Uncloud configuration file.")
 	_ = cmd.MarkPersistentFlagFilename("uncloud-config", "yaml", "yml")
+	// TODO: make --context a global flag and pass it as a value of the command context.
 
 	cmd.AddCommand(
 		NewDeployCommand(),
 		caddy.NewRootCommand(),
+		cmdcontext.NewRootCommand(),
 		dns.NewRootCommand(),
 		machine.NewRootCommand(),
 		service.NewRootCommand(),

cmd/uncloud/service/root.go

@@ -6,8 +6,9 @@ import (
 
 func NewRootCommand() *cobra.Command {
 	cmd := &cobra.Command{
-		Use:   "service",
-		Short: "Manage services in an Uncloud cluster.",
+		Use:     "service",
+		Aliases: []string{"svc"},
+		Short:   "Manage services in an Uncloud cluster.",
 	}
 	cmd.AddCommand(
 		NewInspectCommand(),