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

AkihiroSuda · AkihiroSuda · commit 36fcfde6335d · 2023-09-26T23:52:05.000+09:00
```bash
limactl start --plain
```

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.

Fixes issue 1739

Signed-off-by: Akihiro Suda &lt;akihiro.suda.cz@hco.ntt.co.jp&gt;
diff --git a/cmd/limactl/editflags/editflags.go b/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 {
diff --git a/examples/default.yaml b/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
 # ===================================================================== #
diff --git a/pkg/cidata/cidata.TEMPLATE.d/boot.sh b/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
diff --git a/pkg/cidata/cidata.TEMPLATE.d/lima.env b/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}}
diff --git a/pkg/cidata/cidata.go b/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)
diff --git a/pkg/cidata/template.go b/pkg/cidata/template.go
@@ -81,6 +81,7 @@ type TemplateArgs struct {
 	SkipDefaultDependencyResolution bool
 	VMType                          string
 	VSockPort                       int
+	Plain                           bool
 }
 
 func ValidateTemplateArgs(args TemplateArgs) error {
diff --git a/pkg/hostagent/hostagent.go b/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)
 	}
diff --git a/pkg/hostagent/requirements.go b/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",
diff --git a/pkg/limayaml/defaults.go b/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) {
diff --git a/pkg/limayaml/defaults_test.go b/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...)
diff --git a/pkg/limayaml/limayaml.go b/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
diff --git a/pkg/start/start.go b/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
diff --git a/pkg/vz/vz_driver_darwin.go b/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)
 	}
diff --git a/pkg/wsl2/wsl_driver_windows.go b/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)
 	}
diff --git a/website/content/en/docs/faq/_index.md b/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.

Original file line number	Diff line number	Diff line change
`@@ -88,6 +88,8 @@ func RegisterCreate(cmd *cobra.Command, commentPrefix string) {`
`88`	`88`	`_ = cmd.RegisterFlagCompletionFunc("vm-type", func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {`
`89`	`89`	`return []string{"qemu", "vz"}, cobra.ShellCompDirectiveNoFileComp`
`90`	`90`	`})`
	`91`	`+`
	`92`	`+ flags.Bool("plain", false, commentPrefix+"plain mode. Disable mounts, port forwarding, containerd, etc.")`
`91`	`93`	`}`
`92`	`94`
`93`	`95`	`func defaultExprFunc(expr string) func(v *flag.Flag) (string, error) {`
`@@ -225,6 +227,7 @@ func YQExpressions(flags *flag.FlagSet, newInstance bool) ([]string, error) {`
`225`	`227`
`226`	`228`	`{"disk", d(".disk= \"%sGiB\""), true, false},`
`227`	`229`	`{"vm-type", d(".vmType = %q"), true, false},`
	`230`	`+ {"plain", d(".plain = %s"), true, false},`
`228`	`231`	`}`
`229`	`232`	`var exprs []string`
`230`	`233`	`for _, def := range defs {`
Original file line number	Diff line number	Diff line change
`@@ -135,6 +135,7 @@ func GenerateISO9660(instDir, name string, y *limayaml.LimaYAML, udpDNSLocalPort`
`135`	`135`	`RosettaBinFmt: *y.Rosetta.BinFmt,`
`136`	`136`	`VMType: *y.VMType,`
`137`	`137`	`VSockPort: vsockPort,`
	`138`	`+ Plain: *y.Plain,`
`138`	`139`	`}`
`139`	`140`
`140`	`141`	`firstUsernetIndex := limayaml.FirstUsernetIndex(y)`
Original file line number	Diff line number	Diff line change
`@@ -81,6 +81,7 @@ type TemplateArgs struct {`
`81`	`81`	`SkipDefaultDependencyResolution bool`
`82`	`82`	`VMType string`
`83`	`83`	`VSockPort int`
	`84`	`+ Plain bool`
`84`	`85`	`}`
`85`	`86`
`86`	`87`	`func ValidateTemplateArgs(args TemplateArgs) error {`
Original file line number	Diff line number	Diff line change
`@@ -427,6 +427,9 @@ func (a HostAgent) Info(_ context.Context) (hostagentapi.Info, error) {`
`427`	`427`	`}`
`428`	`428`
`429`	`429`	`func (a *HostAgent) startHostAgentRoutines(ctx context.Context) error {`
	`430`	`+ if *a.y.Plain {`
	`431`	`+ logrus.Info("Running in plain mode. Mounts, port forwarding, containerd, etc. will be ignored. Guest agent will not be running.")`
	`432`	`+ }`
`430`	`433`	`a.onClose = append(a.onClose, func() error {`
`431`	`434`	`logrus.Debugf("shutting down the SSH master")`
`432`	`435`	`if exitMasterErr := ssh.ExitMaster(a.instSSHAddress, a.sshLocalPort, a.sshConfig); exitMasterErr != nil {`
@@ -451,7 +454,7 @@ sudo chown -R "${USER}" /run/host-services`
`451`	`454`	`errs = append(errs, fmt.Errorf("stdout=%q, stderr=%q: %w", stdout, stderr, err))`
`452`	`455`	`}`
`453`	`456`	`}`
`454`		`- if *a.y.MountType == limayaml.REVSSHFS {`
	`457`	`+ if a.y.MountType == limayaml.REVSSHFS && !a.y.Plain {`
`455`	`458`	`mounts, err := a.setupMounts()`
`456`	`459`	`if err != nil {`
`457`	`460`	`errs = append(errs, err)`
@@ -483,7 +486,9 @@ sudo chown -R "${USER}" /run/host-services`
`483`	`486`	`return errors.Join(unlockErrs...)`
`484`	`487`	`})`
`485`	`488`	`}`
`486`		`- go a.watchGuestAgentEvents(ctx)`
	`489`	`+ if !*a.y.Plain {`
	`490`	`+ go a.watchGuestAgentEvents(ctx)`
	`491`	`+ }`
`487`	`492`	`if err := a.waitForRequirements("optional", a.optionalRequirements()); err != nil {`
`488`	`493`	`errs = append(errs, err)`
`489`	`494`	`}`
Original file line number	Diff line number	Diff line change
`@@ -105,6 +105,7 @@ func TestFillDefault(t *testing.T) {`
`105`	`105`	`CACertificates: CACertificates{`
`106`	`106`	`RemoveDefaults: pointer.Bool(false),`
`107`	`107`	`},`
	`108`	`+ Plain: pointer.Bool(false),`
`108`	`109`	`}`
`109`	`110`	`if IsAccelOS() {`
`110`	`111`	`if HasHostCPU() {`
`@@ -405,6 +406,7 @@ func TestFillDefault(t *testing.T) {`
`405`	`406`	`BinFmt: pointer.Bool(true),`
`406`	`407`	`}`
`407`	`408`	`}`
	`409`	`+ expect.Plain = pointer.Bool(false)`
`408`	`410`
`409`	`411`	`y = LimaYAML{}`
`410`	`412`	`FillDefault(&y, &d, &LimaYAML{}, filePath)`
`@@ -617,6 +619,7 @@ func TestFillDefault(t *testing.T) {`
`617`	`619`	`Enabled: pointer.Bool(false),`
`618`	`620`	`BinFmt: pointer.Bool(false),`
`619`	`621`	`}`
	`622`	`+ expect.Plain = pointer.Bool(false)`
`620`	`623`
`621`	`624`	`FillDefault(&y, &d, &o, filePath)`
`622`	`625`	`assert.DeepEqual(t, &y, &expect, opts...)`