Forward Lima guest HTTP port to host

cli_config/cli_config.go

@@ -17,11 +17,12 @@ type VmImage struct {
 }
 
 type VmConfig struct {
-	Manager       string    `yaml:"manager"`
-	HostsResolver string    `yaml:"hosts_resolver"`
-	Images        []VmImage `yaml:"images"`
-	Ubuntu        string    `yaml:"ubuntu"`
-	InstanceName  string    `yaml:"instance_name"`
+	Manager         string    `yaml:"manager"`
+	HostsResolver   string    `yaml:"hosts_resolver"`
+	Images          []VmImage `yaml:"images"`
+	Ubuntu          string    `yaml:"ubuntu"`
+	InstanceName    string    `yaml:"instance_name"`
+	ForwardHttpPort bool      `yaml:"forward_http_port"`
 }
 
 type Config struct {

pkg/lima/manager.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"net"
 	"os"
 	"path/filepath"
 	"strings"
@@ -27,10 +28,17 @@ var (
 	ErrUnsupportedOS = errors.New("unsupported OS or macOS version. The macOS Virtualization Framework requires macOS 13.0 (Ventura) or later.")
 )
 
+type PortFinder interface {
+	Resolve() (int, error)
+}
+
+type TCPPortFinder struct{}
+
 type Manager struct {
 	ConfigPath    string
 	Sites         map[string]*trellis.Site
 	HostsResolver vm.HostsResolver
+	PortFinder    PortFinder
 	ui            cli.Ui
 	trellis       *trellis.Trellis
 }
@@ -55,6 +63,7 @@ func NewManager(trellis *trellis.Trellis, ui cli.Ui) (manager *Manager, err erro
 		ConfigPath:    limaConfigPath,
 		Sites:         trellis.Environments["development"].WordPressSites,
 		HostsResolver: hostsResolver,
+		PortFinder:    &TCPPortFinder{},
 		trellis:       trellis,
 		ui:            ui,
 	}
@@ -78,7 +87,10 @@ func (m *Manager) GetInstance(name string) (Instance, bool) {
 }
 
 func (m *Manager) CreateInstance(name string) error {
-	instance := m.newInstance(name)
+	instance, err := m.newInstance(name)
+	if err != nil {
+		return err
+	}
 
 	cmd := command.WithOptions(
 		command.WithTermOutput(),
@@ -172,7 +184,8 @@ func (m *Manager) StartInstance(name string) error {
 
 	instance.Username = string(user)
 
-	// Hydrate instance with data from limactl that is only available after starting (mainly the forwarded SSH local port)
+	// Hydrate instance with data from limactl that is only available after
+	// starting (mainly the forwarded local ports)
 	err = m.hydrateInstance(&instance)
 	if err != nil {
 		return err
@@ -232,7 +245,7 @@ func (m *Manager) initInstance(instance *Instance) {
 	instance.Sites = m.Sites
 }
 
-func (m *Manager) newInstance(name string) Instance {
+func (m *Manager) newInstance(name string) (Instance, error) {
 	instance := Instance{Name: name}
 	m.initInstance(&instance)
 
@@ -249,9 +262,24 @@ func (m *Manager) newInstance(name string) Instance {
 		images = imagesFromVersion(m.trellis.CliConfig.Vm.Ubuntu)
 	}
 
-	config := Config{Images: images}
+	portForwards := []PortForward{}
+
+	if m.trellis.CliConfig.Vm.ForwardHttpPort {
+		httpForwardPort, err := m.PortFinder.Resolve()
+		if err != nil {
+			return Instance{}, fmt.Errorf("Could not find a local free port for HTTP forwarding: %v", err)
+		}
+
+		portForwards = append(portForwards, PortForward{
+			GuestPort: 80,
+			HostPort:  httpForwardPort,
+		},
+		)
+	}
+
+	config := Config{Images: images, PortForwards: portForwards}
 	instance.Config = config
-	return instance
+	return instance, nil
 }
 
 func (m *Manager) createConfigPath() error {
@@ -329,3 +357,31 @@ func ensureRequirements() error {
 func imagesFromVersion(version string) []Image {
 	return UbuntuImages[version]
 }
+
+func (p *TCPPortFinder) Resolve() (int, error) {
+	lAddr0, err := net.ResolveTCPAddr("tcp4", "127.0.0.1:0")
+	if err != nil {
+		return 0, err
+	}
+
+	l, err := net.ListenTCP("tcp4", lAddr0)
+	if err != nil {
+		return 0, err
+	}
+
+	defer func() { _ = l.Close() }()
+	lAddr := l.Addr()
+
+	lTCPAddr, ok := lAddr.(*net.TCPAddr)
+	if !ok {
+		return 0, fmt.Errorf("expected *net.TCPAddr, got %v", lAddr)
+	}
+
+	port := lTCPAddr.Port
+
+	if port <= 0 {
+		return 0, fmt.Errorf("unexpected port %d", port)
+	}
+
+	return port, nil
+}

pkg/lima/manager_test.go

@@ -15,6 +15,12 @@ type MockHostsResolver struct {
 	Hosts map[string]string
 }
 
+type MockPortFinder struct{}
+
+func (p *MockPortFinder) Resolve() (int, error) {
+	return 60720, nil
+}
+
 func TestNewManager(t *testing.T) {
 	defer trellis.LoadFixtureProject(t)()
 	trellis := trellis.NewTrellis()
@@ -120,7 +126,13 @@ func TestNewInstanceUbuntuVersion(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	instance := manager.newInstance("test")
+	manager.PortFinder = &MockPortFinder{}
+
+	instance, err := manager.newInstance("test")
+
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	if instance.Name != "test" {
 		t.Errorf("expected instance name to be %q, got %q", "test", instance.Name)
@@ -133,6 +145,14 @@ func TestNewInstanceUbuntuVersion(t *testing.T) {
 	if instance.Config.Images[0].Alias != "focal" {
 		t.Errorf("expected instance config to have focal image, got %q", instance.Config.Images[0].Alias)
 	}
+
+	if len(instance.Config.PortForwards) != 1 {
+		t.Errorf("expected instance config to have 1 port forwards, got %d", len(instance.Config.PortForwards))
+	}
+
+	if instance.Config.PortForwards[0].GuestPort != 80 || instance.Config.PortForwards[0].HostPort != 60720 {
+		t.Errorf("expected instance config to have port forward guest 80 to host 60720, got guest %d to host %d", instance.Config.PortForwards[0].GuestPort, instance.Config.PortForwards[0].HostPort)
+	}
 }
 func TestInstances(t *testing.T) {
 	defer trellis.LoadFixtureProject(t)()
@@ -197,6 +217,7 @@ func TestCreateInstance(t *testing.T) {
 
 	hostsStorage := make(map[string]string)
 	manager.HostsResolver = &MockHostsResolver{Hosts: hostsStorage}
+	manager.PortFinder = &MockPortFinder{}
 
 	instanceName := "test"
 	sshPort := 60720

trellis/trellis.go

@@ -36,10 +36,11 @@ var DefaultCliConfig = cli_config.Config{
 	Open:                    make(map[string]string),
 	VirtualenvIntegration:   true,
 	Vm: cli_config.VmConfig{
-		Manager:       "auto",
-		HostsResolver: "hosts_file",
-		Ubuntu:        "24.04",
-		InstanceName:  "",
+		Manager:         "auto",
+		HostsResolver:   "hosts_file",
+		Ubuntu:          "24.04",
+		InstanceName:    "",
+		ForwardHttpPort: true,
 	},
 }