Do guest template expansion for provisioning scripts

The LIMA_CIDATA_* variables are not a supported API and can
change without warning.

Signed-off-by: Jan Dubois <[email protected]>

Author: jandubois

examples/default.yaml

@@ -184,6 +184,7 @@ containerd:
 
 # Provisioning scripts need to be idempotent because they might be called
 # multiple times, e.g. when the host VM is being restarted.
+# The scripts can use the following template variables: {{.Home}}, {{.UID}}, and {{.User}}
 # 🟢 Builtin default: null
 # provision:
 # # `system` is executed with the root privilege

examples/docker-rootful.yaml

@@ -6,7 +6,7 @@
 # $ export DOCKER_HOST=$(limactl list docker-rootful --format 'unix://{{.Dir}}/sock/docker.sock')
 # $ docker ...
 
-# This template requires Lima v0.8.0 or later
+# This template requires Lima v0.20.0 or later
 images:
 # Try to use release-yyyyMMdd image if available. Note that release-yyyyMMdd will be removed after several months.
 - location: "https://cloud-images.ubuntu.com/releases/22.04/release-20231211/ubuntu-22.04-server-cloudimg-amd64.img"
@@ -49,7 +49,7 @@ provision:
       # Alternatively we could just add the user to the "docker" group, but that requires restarting the user session
       cat <<-EOF >/etc/systemd/system/docker.socket.d/override.conf
       [Socket]
-      SocketUser=${LIMA_CIDATA_USER}
+      SocketUser={{.User}}
     EOF
     fi
     export DEBIAN_FRONTEND=noninteractive

examples/experimental/vnc.yaml

@@ -1,5 +1,5 @@
 # A template to run ubuntu using display: vnc
-# This template requires Lima v0.15.0 or later.
+# This template requires Lima v0.20.0 or later.
 images:
 # Try to use release-yyyyMMdd image if available. Note that release-yyyyMMdd will be removed after several months.
 - location: "https://cloud-images.ubuntu.com/releases/23.10/release-20231011/ubuntu-23.10-server-cloudimg-amd64.img"
@@ -33,7 +33,7 @@ provision:
     export DEBIAN_FRONTEND=noninteractive
     # x-terminal-emulator x-session-manager x-window-manager
     apt-get install -y xorg xterm openbox hsetroot tint2 slim
-    printf "auto_login yes\ndefault_user ${LIMA_CIDATA_USER}\n" >>/etc/slim.conf
+    printf "auto_login yes\ndefault_user {{.User}}\n" >>/etc/slim.conf
     # configure some nice lima green, set up panel and apps
     printf "hsetroot -solid \"#32CD32\" &\ntint2 &\n" >>/etc/xdg/openbox/autostart
     sed -i 's/Clearlooks/Clearlooks-Olive/' /etc/xdg/openbox/rc.xml # go for green

examples/podman-rootful.yaml

@@ -10,7 +10,7 @@
 # $ export DOCKER_HOST=$(limactl list podman-rootful --format 'unix://{{.Dir}}/sock/podman.sock')
 # $ docker ...
 
-# This template requires Lima v0.8.0 or later
+# This template requires Lima v0.20.0 or later
 images:
 - location: "https://download.fedoraproject.org/pub/fedora/linux/releases/39/Cloud/x86_64/images/Fedora-Cloud-Base-39-1.5.x86_64.qcow2"
   arch: "x86_64"
@@ -36,12 +36,12 @@ provision:
       mkdir -p /etc/systemd/system/podman.socket.d
       cat <<-EOF >/etc/systemd/system/podman.socket.d/override.conf
       [Socket]
-      SocketUser=${LIMA_CIDATA_USER}
+      SocketUser={{.User}}
     EOF
     fi
     if [ ! -e /etc/tmpfiles.d/podman.conf ]; then
       mkdir -p /etc/tmpfiles.d
-      echo "d /run/podman 0700 ${LIMA_CIDATA_USER} -" > /etc/tmpfiles.d/podman.conf
+      echo "d /run/podman 0700 {{.User}} -" > /etc/tmpfiles.d/podman.conf
     fi
     dnf -y install podman
 - mode: system

pkg/limayaml/defaults.go

@@ -427,6 +427,11 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 		if provision.Mode == ProvisionModeDependency && provision.SkipDefaultDependencyResolution == nil {
 			provision.SkipDefaultDependencyResolution = ptr.Of(false)
 		}
+		if out, err := executeGuestTemplate(provision.Script); err == nil {
+			provision.Script = out.String()
+		} else {
+			logrus.WithError(err).Warnf("Couldn't process provisioning script %q as a template", provision.Script)
+		}
 	}
 
 	if y.GuestInstallPrefix == nil {
@@ -795,7 +800,7 @@ func executeHostTemplate(format, instDir string) (bytes.Buffer, error) {
 			"User": user.Username,
 
 			"Instance": filepath.Base(instDir), // DEPRECATED, use `{{.Name}}`
-			"LimaHome": limaHome,               // DEPRECATED, (use `Dir` instead of `{{.LimaHome}}/{{.Instance}}`
+			"LimaHome": limaHome,               // DEPRECATED, use `{{.Dir}}` instead of `{{.LimaHome}}/{{.Instance}}`
 		}
 		var out bytes.Buffer
 		if err := tmpl.Execute(&out, data); err == nil {