Add initial support for alpine autoinstall

Run setup-disk on the biggest empty disk found when autoinstall: true is
set.

lib/tiny-cloud/user-data/alpine-config

@@ -7,7 +7,7 @@ INIT_ACTIONS_MAIN="$(insert_after set_hostname \
 	"userdata_bootcmd userdata_write_files userdata_ntp userdata_apk_cache userdata_apk_repositories userdata_package_update userdata_package_upgrade userdata_packages" \
 	$INIT_ACTIONS_MAIN)"
 INIT_ACTIONS_MAIN="$(insert_after set_ssh_keys ssh_authorized_keys $INIT_ACTIONS_MAIN)"
-INIT_ACTIONS_FINAL="$INIT_ACTIONS_FINAL userdata_runcmd"
+INIT_ACTIONS_FINAL="$INIT_ACTIONS_FINAL userdata_runcmd userdata_autoinstall"
 
 get_userdata() {
 	IFS="/"
@@ -227,3 +227,29 @@ init__userdata_runcmd() {
 		sh -c "$cmd"
 	done
 }
+
+find_biggest_empty_disk() {
+	local d
+	for d in  "$ROOT"/sys/class/block/*/device; do
+		p=${d%/device}
+		if [ -e "$p"/size ] && [ -z "$(blkid /dev/${p##*/})" ]; then
+			echo "$(cat $p/size) ${p##*/}"
+		fi
+	done | sort -n | tail -n 1 | cut -d' ' -f2
+}
+
+init__userdata_autoinstall() {
+	local autoinstall="$(get_userdata autoinstall)"
+	if [ "$autoinstall" = "true" ]; then
+		local disk="$(find_biggest_empty_disk)"
+		if [ -n "$disk" ]; then
+			rm -f "$ROOT"/etc/runlevels/*/tiny-cloud*
+			$MOCK lbu include /root/.ssh /home
+			$MOCK ERASE_DISKS=/dev/$disk setup-disk -m sys /dev/$disk
+			# TODO: make reboot configurable
+			$MOCK reboot
+		else
+			log err "no empty disk found"
+		fi
+	fi
+}

tests/test_env.sh

@@ -120,3 +120,10 @@ fake_interfaces() {
 		n=$((n+1))
 	done
 }
+
+fake_disk() {
+	local dev="$1" size="$2"
+	mkdir -p sys/class/block/$dev
+	touch sys/class/block/$dev/device
+	echo "$size" > sys/class/block/$1/size
+}

tests/tiny-cloud-alpine.test

@@ -28,7 +28,8 @@ init_tests \
 	userdata_package_update \
 	userdata_package_upgrade \
 	userdata_packages \
-	userdata_runcmd
+	userdata_runcmd \
+	userdata_autoinstall
 
 set_ephemeral_network_cmdline_body() {
 	fake_interfaces eth0 eth1 eth2
@@ -413,3 +414,24 @@ userdata_write_files_body() {
 		world
 	EOF
 }
+
+userdata_autoinstall_body() {
+	fake_userdata_nocloud <<-EOF
+		#alpine-config
+		autoinstall: true
+	EOF
+	fake_bin blkid <<-EOF
+		#!/bin/sh
+		true
+	EOF
+	fake_disk nvme0n8 10000
+	fake_disk vda 20000
+
+	# run net phase to extract the user data
+	atf_check -e ignore -o ignore tiny-cloud early
+	atf_check \
+		-e match:"userdata_autoinstall: done" \
+		-o match:"setup-disk" \
+		tiny-cloud final
+}
+