Add "plain" mode (disables mounts, port forwarding, containerd, etc.)

cmd/limactl/editflags/editflags.go

@@ -88,6 +88,8 @@ func RegisterCreate(cmd *cobra.Command, commentPrefix string) {
 	_ = cmd.RegisterFlagCompletionFunc("vm-type", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
 		return []string{"qemu", "vz"}, cobra.ShellCompDirectiveNoFileComp
 	})
+
+	flags.Bool("plain", false, commentPrefix+"plain mode. Disable mounts, port forwarding, containerd, etc.")
 }
 
 func defaultExprFunc(expr string) func(v *flag.Flag) (string, error) {
@@ -225,6 +227,7 @@ func YQExpressions(flags *flag.FlagSet, newInstance bool) ([]string, error) {
 
 		{"disk", d(".disk= \"%sGiB\""), true, false},
 		{"vm-type", d(".vmType = %q"), true, false},
+		{"plain", d(".plain = %s"), true, false},
 	}
 	var exprs []string
 	for _, def := range defs {

examples/default.yaml

@@ -444,6 +444,14 @@ hostResolver:
 # 🟢 Builtin default: /usr/local
 guestInstallPrefix: null
 
+# When the "plain" mode is enabled:
+# - the YAML properties for mounts, port forwarding, containerd, etc. will be ignored
+# - guest agent will not be running
+# - dependency packages like sshfs will not be installed into the VM
+# User-specified provisioning scripts will be still executed.
+# 🟢 Builtin default: false
+plain: null
+
 # ===================================================================== #
 # GLOBAL DEFAULTS AND OVERRIDES
 # ===================================================================== #

pkg/cidata/cidata.TEMPLATE.d/boot.sh

@@ -34,13 +34,17 @@ CODE=0
 # has run because it might move the directories to /mnt/data on first boot. In that
 # case changes made on restart would be lost.
 
-for f in "${LIMA_CIDATA_MNT}"/boot/*; do
-	INFO "Executing $f"
-	if ! "$f"; then
-		WARNING "Failed to execute $f"
-		CODE=1
-	fi
-done
+if [ "$LIMA_CIDATA_PLAIN" = "1" ]; then
+	INFO "Plain mode. Skipping to run boot scripts. Provisioning scripts will be still executed. Guest agent will not be running."
+else
+	for f in "${LIMA_CIDATA_MNT}"/boot/*; do
+		INFO "Executing $f"
+		if ! "$f"; then
+			WARNING "Failed to execute $f"
+			CODE=1
+		fi
+	done
+fi
 
 if [ -d "${LIMA_CIDATA_MNT}"/provision.system ]; then
 	for f in "${LIMA_CIDATA_MNT}"/provision.system/*; do

pkg/cidata/cidata.TEMPLATE.d/lima.env

@@ -41,3 +41,8 @@ LIMA_CIDATA_SKIP_DEFAULT_DEPENDENCY_RESOLUTION=
 {{- end}}
 LIMA_CIDATA_VMTYPE={{ .VMType }}
 LIMA_CIDATA_VSOCK_PORT={{ .VSockPort }}
+{{- if .Plain}}
+LIMA_CIDATA_PLAIN=1
+{{- else}}
+LIMA_CIDATA_PLAIN=
+{{- end}}

pkg/cidata/cidata.go

@@ -135,6 +135,7 @@ func GenerateISO9660(instDir, name string, y *limayaml.LimaYAML, udpDNSLocalPort
 		RosettaBinFmt:  *y.Rosetta.BinFmt,
 		VMType:         *y.VMType,
 		VSockPort:      vsockPort,
+		Plain:          *y.Plain,
 	}
 
 	firstUsernetIndex := limayaml.FirstUsernetIndex(y)

pkg/cidata/template.go

@@ -81,6 +81,7 @@ type TemplateArgs struct {
 	SkipDefaultDependencyResolution bool
 	VMType                          string
 	VSockPort                       int
+	Plain                           bool
 }
 
 func ValidateTemplateArgs(args TemplateArgs) error {

pkg/hostagent/hostagent.go

@@ -427,6 +427,9 @@ func (a *HostAgent) Info(_ context.Context) (*hostagentapi.Info, error) {
 }
 
 func (a *HostAgent) startHostAgentRoutines(ctx context.Context) error {
+	if *a.y.Plain {
+		logrus.Info("Running in plain mode. Mounts, port forwarding, containerd, etc. will be ignored. Guest agent will not be running.")
+	}
 	a.onClose = append(a.onClose, func() error {
 		logrus.Debugf("shutting down the SSH master")
 		if exitMasterErr := ssh.ExitMaster(a.instSSHAddress, a.sshLocalPort, a.sshConfig); exitMasterErr != nil {
@@ -451,7 +454,7 @@ sudo chown -R "${USER}" /run/host-services`
 			errs = append(errs, fmt.Errorf("stdout=%q, stderr=%q: %w", stdout, stderr, err))
 		}
 	}
-	if *a.y.MountType == limayaml.REVSSHFS {
+	if *a.y.MountType == limayaml.REVSSHFS && !*a.y.Plain {
 		mounts, err := a.setupMounts()
 		if err != nil {
 			errs = append(errs, err)
@@ -483,7 +486,9 @@ sudo chown -R "${USER}" /run/host-services`
 			return errors.Join(unlockErrs...)
 		})
 	}
-	go a.watchGuestAgentEvents(ctx)
+	if !*a.y.Plain {
+		go a.watchGuestAgentEvents(ctx)
+	}
 	if err := a.waitForRequirements("optional", a.optionalRequirements()); err != nil {
 		errs = append(errs, err)
 	}

pkg/hostagent/requirements.go

@@ -71,7 +71,11 @@ true
 Make sure that the YAML field "ssh.localPort" is not used by other processes on the host.
 If any private key under ~/.ssh is protected with a passphrase, you need to have ssh-agent to be running.
 `,
-		},
+		})
+	if *a.y.Plain {
+		return req
+	}
+	req = append(req,
 		requirement{
 			description: "user session is ready for ssh",
 			script: `#!/bin/bash
@@ -156,7 +160,7 @@ A possible workaround is to run "lima-guestagent install-systemd" in the guest.
 
 func (a *HostAgent) optionalRequirements() []requirement {
 	req := make([]requirement, 0)
-	if *a.y.Containerd.System || *a.y.Containerd.User {
+	if (*a.y.Containerd.System || *a.y.Containerd.User) && !*a.y.Plain {
 		req = append(req,
 			requirement{
 				description: "systemd must be available",

pkg/limayaml/defaults.go

@@ -665,6 +665,30 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 	if y.Rosetta.BinFmt == nil {
 		y.Rosetta.BinFmt = pointer.Bool(false)
 	}
+
+	if y.Plain == nil {
+		y.Plain = d.Plain
+	}
+	if o.Plain != nil {
+		y.Plain = o.Plain
+	}
+	if y.Plain == nil {
+		y.Plain = pointer.Bool(false)
+	}
+
+	fixUpForPlainMode(y)
+}
+
+func fixUpForPlainMode(y *LimaYAML) {
+	if !*y.Plain {
+		return
+	}
+	y.Mounts = nil
+	y.PortForwards = nil
+	y.Containerd.System = pointer.Bool(false)
+	y.Containerd.User = pointer.Bool(false)
+	y.Rosetta.BinFmt = pointer.Bool(false)
+	y.Rosetta.Enabled = pointer.Bool(false)
 }
 
 func executeGuestTemplate(format string) (bytes.Buffer, error) {

pkg/limayaml/defaults_test.go

@@ -105,6 +105,7 @@ func TestFillDefault(t *testing.T) {
 		CACertificates: CACertificates{
 			RemoveDefaults: pointer.Bool(false),
 		},
+		Plain: pointer.Bool(false),
 	}
 	if IsAccelOS() {
 		if HasHostCPU() {
@@ -405,6 +406,7 @@ func TestFillDefault(t *testing.T) {
 			BinFmt:  pointer.Bool(true),
 		}
 	}
+	expect.Plain = pointer.Bool(false)
 
 	y = LimaYAML{}
 	FillDefault(&y, &d, &LimaYAML{}, filePath)
@@ -617,6 +619,7 @@ func TestFillDefault(t *testing.T) {
 		Enabled: pointer.Bool(false),
 		BinFmt:  pointer.Bool(false),
 	}
+	expect.Plain = pointer.Bool(false)
 
 	FillDefault(&y, &d, &o, filePath)
 	assert.DeepEqual(t, &y, &expect, opts...)

pkg/limayaml/limayaml.go

@@ -38,6 +38,7 @@ type LimaYAML struct {
 	PropagateProxyEnv *bool          `yaml:"propagateProxyEnv,omitempty" json:"propagateProxyEnv,omitempty"`
 	CACertificates    CACertificates `yaml:"caCerts,omitempty" json:"caCerts,omitempty"`
 	Rosetta           Rosetta        `yaml:"rosetta,omitempty" json:"rosetta,omitempty"`
+	Plain             *bool          `yaml:"plain,omitempty" json:"plain,omitempty"`
 }
 
 type OS = string

pkg/start/start.go

@@ -240,7 +240,11 @@ func watchHostAgentEvents(ctx context.Context, inst *store.Instance, haStdoutPat
 				return true
 			}
 
-			logrus.Infof("READY. Run `%s` to open the shell.", LimactlShellCmd(inst.Name))
+			if *inst.Config.Plain {
+				logrus.Infof("READY. Run `ssh -F %q lima-%s` to open the shell.", inst.SSHConfigFile, inst.Name)
+			} else {
+				logrus.Infof("READY. Run `%s` to open the shell.", LimactlShellCmd(inst.Name))
+			}
 			ShowMessage(inst)
 			err = nil
 			return true

pkg/vz/vz_driver_darwin.go

@@ -74,6 +74,7 @@ func (l *LimaVzDriver) Validate() error {
 		"Audio",
 		"Video",
 		"OS",
+		"Plain",
 	); len(unknown) > 0 {
 		logrus.Warnf("vmType %s: ignoring %+v", *l.Yaml.VMType, unknown)
 	}

pkg/wsl2/wsl_driver_windows.go

@@ -49,6 +49,7 @@ func (l *LimaWslDriver) Validate() error {
 		"DNS",
 		"HostResolver",
 		"PropagateProxyEnv",
+		"Plain",
 	); len(unknown) > 0 {
 		logrus.Warnf("Ignoring: vmType %s: %+v", *l.Yaml.VMType, unknown)
 	}

website/content/en/docs/faq/_index.md

@@ -16,6 +16,8 @@ weight: 6
   - ["Can I run other container engines such as Docker and Podman? What about Kubernetes?"](#can-i-run-other-container-engines-such-as-docker-and-podman-what-about-kubernetes)
   - ["Can I run Lima with a remote Linux machine?"](#can-i-run-lima-with-a-remote-linux-machine)
   - ["Advantages compared to Docker for Mac?"](#advantages-compared-to-docker-for-mac)
+- [Configuration](#configuration)
+  - ["Is it possible to disable mounts, port forwarding, containerd, etc. ?"](#is-it-possible-to-disable-mounts-port-forwarding-containerd-etc-)
 - [QEMU](#qemu)
   - ["QEMU crashes with `HV_ERROR`"](#qemu-crashes-with-hv_error)
   - ["QEMU is slow"](#qemu-is-slow)
@@ -105,6 +107,32 @@ and forward `localhost:8080` to the port 80 of the remote machine.
 #### "Advantages compared to Docker for Mac?"
 Lima is free software (Apache License 2.0), while Docker for Mac is not.
 
+### Configuration
+#### "Is it possible to disable mounts, port forwarding, containerd, etc. ?"
+
+Yes, since Lima v0.18:
+
+{{< tabpane text=true >}}
+{{% tab header="CLI" %}}
+```bash
+limactl start --plain
+```
+{{% /tab %}}
+{{% tab header="YAML" %}}
+```yaml
+plain: true
+```
+{{% /tab %}}
+{{< /tabpane >}}
+
+
+When the "plain" mode is enabled:
+- the YAML properties for mounts, port forwarding, containerd, etc. will be ignored
+- guest agent will not be running
+- dependency packages like sshfs will not be installed into the VM
+
+User-specified provisioning scripts will be still executed.
+
 ### QEMU
 #### "QEMU crashes with `HV_ERROR`"
 If you have installed QEMU v6.0.0 or later on macOS 11 via homebrew, your QEMU binary should have been already automatically signed to enable HVF acceleration.