Add documentation and example for ext

Signed-off-by: Anders F Björklund <anders.f.bjorklund@gmail.com>

Author: afbjorklund

examples/README.md

@@ -29,6 +29,9 @@ Distro:
 - [`experimental/gentoo`](./experimental/gentoo.yaml): [experimental] Gentoo
 - [`experimental/opensuse-tumbleweed`](./experimental/opensuse-tumbleweed.yaml): [experimental] openSUSE Tumbleweed
 
+External:
+- [`experimental/ext`](./experimental/ext.yaml): [experimental] External Raspberry Pi Zero
+
 Container engines:
 - [`apptainer`](./apptainer.yaml): Apptainer
 - [`apptainer-rootful`](./apptainer-rootful.yaml): Apptainer (rootful)

examples/experimental/ext.yaml

@@ -0,0 +1,14 @@
+vmType: ext
+
+arch: "aarch64"
+cpus: 4
+memory: 512MiB
+disk: 32GiB
+
+mounts:
+- location: "~"
+- location: "/tmp/lima"
+  writable: true
+
+ssh:
+  address: raspberrypi.local

pkg/limayaml/validate.go

@@ -483,6 +483,9 @@ func warnExperimental(y *LimaYAML) {
 	if *y.MountType == VIRTIOFS && runtime.GOOS == "linux" {
 		logrus.Warn("`mountType: virtiofs` on Linux is experimental")
 	}
+	if *y.VMType == EXT {
+		logrus.Warn("`vmType: ext` is experimental")
+	}
 	if *y.Arch == RISCV64 {
 		logrus.Warn("`arch: riscv64` is experimental")
 	}

website/content/en/docs/config/vmtype/_index.md

@@ -7,6 +7,9 @@ Lima supports two ways of running guest machines:
 - [qemu](#qemu)
 - [vz](#vz)
 
+Lima also supports connecting to external machines:
+- [ext](#ext)
+
 The vmType can be specified only on creating the instance.
 The vmType of existing instances cannot be changed.
 
@@ -113,3 +116,11 @@ containerd:
 - When running lima using "wsl2", `${LIMA_HOME}/<INSTANCE>/serial.log` will not contain kernel boot logs
 - WSL2 requires a `tar` formatted rootfs archive instead of a VM image
 - Windows doesn't ship with ssh.exe, gzip.exe, etc. which are used by Lima at various points. The easiest way around this is to run `winget install -e --id Git.MinGit` (winget is now built in to Windows as well), and add the resulting `C:\Program Files\Git\usr\bin\` directory to your path.
+
+## EXT
+> **Warning**
+> "ext" mode is experimental
+
+"ext" option makes use of an external machine, either a virtual machine or a physical machine.
+
+It is accessed using an address (for SSH), the keys are supposed to be set up for it already.