feat: try each cluster connection in order until one succeeds, add progress spinner

internal/cli/cli.go

@@ -2,7 +2,6 @@ package cli
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"net/netip"
 	"os"
@@ -10,7 +9,6 @@ import (
 
 	"github.com/docker/cli/cli/streams"
 	"github.com/psviderski/uncloud/internal/cli/config"
-	"github.com/psviderski/uncloud/internal/fs"
 	"github.com/psviderski/uncloud/internal/machine"
 	"github.com/psviderski/uncloud/internal/machine/api/pb"
 	"github.com/psviderski/uncloud/internal/sshexec"
@@ -73,8 +71,18 @@ func (cli *CLI) SetCurrentContext(name string) error {
 // ConnectCluster connects to a cluster using the given context name or the current context if not specified.
 // If the CLI was initialised with a machine connection, the config is ignored and the connection is used instead.
 func (cli *CLI) ConnectCluster(ctx context.Context, contextName string) (*client.Client, error) {
+	return cli.ConnectClusterWithOptions(ctx, contextName, ConnectOptions{
+		// Default to showing progress for CLI usage.
+		ShowProgress: true,
+	})
+}
+
+// ConnectClusterWithOptions connects to a cluster using the given context name and options.
+// If the CLI was initialised with a machine connection, the config is ignored and the connection is used instead.
+// Options are useful when using the CLI as a library where you may want to disable visual feedback.
+func (cli *CLI) ConnectClusterWithOptions(ctx context.Context, contextName string, opts ConnectOptions) (*client.Client, error) {
 	if cli.conn != nil {
-		return connectCluster(ctx, *cli.conn)
+		return ConnectCluster(ctx, *cli.conn, opts)
 	}
 
 	if len(cli.Config.Contexts) == 0 {
@@ -116,38 +124,20 @@ func (cli *CLI) ConnectCluster(ctx context.Context, contextName string) (*client
 		)
 	}
 
-	// TODO: iterate over all connections and try to connect to the cluster using the first successful connection.
-	conn := cfg.Connections[0]
-
-	c, err := connectCluster(ctx, conn)
-	if err != nil {
-		return nil, fmt.Errorf("connect to cluster (context '%s'): %w", contextName, err)
-	}
-
-	return c, nil
-}
-
-func connectCluster(ctx context.Context, conn config.MachineConnection) (*client.Client, error) {
-	if conn.SSH != "" {
-		user, host, port, err := conn.SSH.Parse()
-		if err != nil {
-			return nil, fmt.Errorf("parse SSH connection %q: %w", conn.SSH, err)
+	// Try each connection in order until one succeeds.
+	var lastErr error
+	for _, conn := range cfg.Connections {
+		c, err := ConnectCluster(ctx, conn, opts)
+		if err == nil {
+			return c, nil
 		}
 
-		keyPath := fs.ExpandHomeDir(conn.SSHKeyFile)
-
-		sshConfig := &connector.SSHConnectorConfig{
-			User:    user,
-			Host:    host,
-			Port:    port,
-			KeyPath: keyPath,
-		}
-		return client.New(ctx, connector.NewSSHConnector(sshConfig))
-	} else if conn.TCP != nil && conn.TCP.IsValid() {
-		return client.New(ctx, connector.NewTCPConnector(*conn.TCP))
+		lastErr = err
 	}
 
-	return nil, errors.New("connection configuration is invalid")
+	return nil, fmt.Errorf("failed to connect to cluster context '%s': "+
+		"all connections (%d) in the Uncloud config (%s) failed; last error: %w",
+		contextName, len(cfg.Connections), cli.Config.Path(), lastErr)
 }
 
 type InitClusterOptions struct {

internal/cli/config/connection.go

@@ -1,6 +1,7 @@
 package config
 
 import (
+	"fmt"
 	"net"
 	"net/netip"
 	"strconv"
@@ -24,6 +25,15 @@ type MachineConnection struct {
 	PublicKey secret.Secret   `yaml:"public_key,omitempty"`
 }
 
+func (c MachineConnection) String() string {
+	if c.SSH != "" {
+		return string(c.SSH)
+	} else if c.TCP != nil && c.TCP.IsValid() {
+		return fmt.Sprintf("tcp://%s", c.TCP)
+	}
+	return "unknown connection"
+}
+
 // SSHDestination represents an SSH destination string in the canonical form of "user@host:port".
 // The default user "root" and port 22 can be omitted.
 type SSHDestination string

internal/cli/connect.go

@@ -0,0 +1,189 @@
+package cli
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/charmbracelet/bubbles/spinner"
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
+	"github.com/psviderski/uncloud/internal/cli/config"
+	"github.com/psviderski/uncloud/internal/fs"
+	"github.com/psviderski/uncloud/pkg/client"
+	"github.com/psviderski/uncloud/pkg/client/connector"
+)
+
+// ConnectOptions configures the behavior of cluster connection attempts.
+type ConnectOptions struct {
+	// Whether to show connection progress spinner if stdout is a terminal or progress logs if not.
+	ShowProgress bool
+}
+
+func ConnectCluster(ctx context.Context, conn config.MachineConnection, opts ConnectOptions) (*client.Client, error) {
+	if opts.ShowProgress {
+		return connectClusterWithProgress(ctx, conn)
+	}
+	return connectCluster(ctx, conn)
+}
+
+// connectClusterWithProgress connects to the cluster while displaying a progress spinner.
+// If the stdout is not a terminal, it falls back to simple progress logs to stderr.
+func connectClusterWithProgress(ctx context.Context, conn config.MachineConnection) (*client.Client, error) {
+	// If stdout is not a terminal, fall back to simple progress logs.
+	if !IsStdoutTerminal() {
+		fmt.Fprintln(os.Stderr, "Connecting to", conn.String())
+		cli, err := connectCluster(ctx, conn)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "Connection failed:", err)
+		} else {
+			fmt.Fprintln(os.Stderr, "Connected to cluster.")
+		}
+		return cli, err
+	}
+
+	// Run the connection TUI model.
+	p := tea.NewProgram(newConnectModel(ctx, conn))
+	model, err := p.Run()
+	if err != nil {
+		return nil, fmt.Errorf("run connection TUI: %w", err)
+	}
+
+	m := model.(connectModel)
+	return m.result.client, m.result.err
+}
+
+func connectCluster(ctx context.Context, conn config.MachineConnection) (*client.Client, error) {
+	if conn.SSH != "" {
+		user, host, port, err := conn.SSH.Parse()
+		if err != nil {
+			return nil, fmt.Errorf("parse SSH connection %q: %w", conn.SSH, err)
+		}
+
+		keyPath := fs.ExpandHomeDir(conn.SSHKeyFile)
+
+		sshConfig := &connector.SSHConnectorConfig{
+			User:    user,
+			Host:    host,
+			Port:    port,
+			KeyPath: keyPath,
+		}
+		return client.New(ctx, connector.NewSSHConnector(sshConfig))
+	} else if conn.TCP != nil && conn.TCP.IsValid() {
+		return client.New(ctx, connector.NewTCPConnector(*conn.TCP))
+	}
+
+	return nil, errors.New("connection configuration is invalid")
+}
+
+// connectModel is a TUI model for connecting to a cluster with a progress spinner.
+type connectModel struct {
+	ctx     context.Context
+	conn    config.MachineConnection
+	spinner spinner.Model
+	// showSpinner controls whether the spinner is visible (delayed to avoid flashing).
+	showSpinner bool
+	// done indicates whether the connection attempt has completed (successfully or with error).
+	done bool
+	// result holds the result of the connection attempt.
+	result connectResultMsg
+}
+
+type connectResultMsg struct {
+	client *client.Client
+	err    error
+}
+
+// showSpinnerMsg is sent after a delay to show the spinner.
+type showSpinnerMsg struct{}
+
+func newConnectModel(ctx context.Context, conn config.MachineConnection) connectModel {
+	s := spinner.New()
+	s.Spinner = spinner.MiniDot
+	s.Style = lipgloss.NewStyle().Foreground(lipgloss.Color("3")) // the same yellow as in compose progress
+
+	return connectModel{
+		ctx:     ctx,
+		conn:    conn,
+		spinner: s,
+	}
+}
+
+func (m connectModel) Init() tea.Cmd {
+	return tea.Batch(
+		m.spinner.Tick,
+		m.connect(),
+		m.delayShowSpinner(),
+	)
+}
+
+func (m connectModel) connect() tea.Cmd {
+	return func() tea.Msg {
+		cli, err := connectCluster(m.ctx, m.conn)
+		return connectResultMsg{
+			client: cli,
+			err:    err,
+		}
+	}
+}
+
+// delayShowSpinner returns a command that sends a message to show the spinner after a delay.
+// This avoids flashing the spinner if the connection is fast.
+func (m connectModel) delayShowSpinner() tea.Cmd {
+	return tea.Tick(500*time.Millisecond, func(t time.Time) tea.Msg {
+		return showSpinnerMsg{}
+	})
+}
+
+func (m connectModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	select {
+	case <-m.ctx.Done():
+		m.result.err = m.ctx.Err()
+		m.done = true
+		return m, tea.Quit
+	default:
+	}
+
+	switch msg := msg.(type) {
+	case connectResultMsg:
+		m.result = msg
+		m.done = true
+		return m, tea.Quit
+
+	case showSpinnerMsg:
+		// Only show spinner if connection hasn't completed yet.
+		if !m.done {
+			m.showSpinner = true
+		}
+		return m, nil
+
+	case spinner.TickMsg:
+		var cmd tea.Cmd
+		m.spinner, cmd = m.spinner.Update(msg)
+		return m, cmd
+
+	case tea.KeyMsg:
+		if msg.Type == tea.KeyCtrlC {
+			m.result.err = fmt.Errorf("connection cancelled")
+			m.done = true
+			return m, tea.Quit
+		}
+	}
+
+	return m, nil
+}
+
+func (m connectModel) View() string {
+	// Don't show anything if done or spinner not yet visible.
+	if m.done || !m.showSpinner {
+		return ""
+	}
+
+	style := lipgloss.NewStyle().Foreground(lipgloss.Color("153"))
+	return fmt.Sprintf("%s %s\n",
+		m.spinner.View(),
+		fmt.Sprintf("Connecting to %s", style.Render(m.conn.String())),
+	)
+}

internal/cli/prompt.go

@@ -31,3 +31,8 @@ func Confirm() (bool, error) {
 func IsStdinTerminal() bool {
 	return term.IsTerminal(int(os.Stdin.Fd()))
 }
+
+// IsStdoutTerminal checks if the standard output is a terminal (TTY).
+func IsStdoutTerminal() bool {
+	return term.IsTerminal(int(os.Stdout.Fd()))
+}