Accepting request 835192 from home:favogt:combustion

- Overhaul configuration fetching:
  * Add udev rules to wait for either ignition, combustion or
    fw_cfg drives
  * Allow combustion.firstboot in addition to ignition.firstboot
  M combustion
  A combustion-prepare.service
  M combustion.service
  M module-setup.sh
- Bump version to 0.2

OBS-URL: https://build.opensuse.org/request/show/835192
OBS-URL: https://build.opensuse.org/package/show/devel:kubic:ignition/combustion?expand=0&rev=7

README

@@ -13,12 +13,17 @@ snapshot, so that no reboot is needed.
 How to use it
 -------------
 
-To be compatible and co-installable with ignition
-(https://github.com/coreos/ignition), the configuration files are copied from
-a filesystem with the LABEL "ignition".
+The configuration files are copied from a filesystem with the LABEL
+"combustion", but to be compatible and co-installable with ignition
+(https://github.com/coreos/ignition), the LABEL "ignition" is used as fallback.
 It expects a directory "combustion" at the root level of the filesystem and
 a file "script" inside, which is executed inside a transactional-update shell.
 
+If a QEMU fw_cfg blob with the name "opt/org.opensuse.combustion/script" is
+found, it is preferred and the content of that is used as script.
+Example parameter for QEMU:
+-fw_cfg name=opt/org.opensuse.combustion/script,file=/var/combustion-script
+
 Example for formatting a USB drive and adding a config, which installs the
 "vim-small" package and creates a /root/welcome file:
 
@@ -54,12 +59,12 @@ kernel commandline.
 
 If this option is found on the kernel cmdline, combustion.service's
 ConditionKernelCommandLine is fulfilled and it'll be required by initrd.target.
-This pulls in combustion-prepare.service, which runs after the config drive
-with LABEL=ignition appears. It is mounted and if the "network" flag comment is
-present, enables networking for later. After /sysroot is mounted and network is
-up (if enabled), combustion.service runs, which tries to activate all
-mountpoints in the system's /etc/fstab and then calls transactional-update
-in a chroot.
+This pulls in combustion-prepare.service, which runs after the config drive or
+QEMU fw_cfg blob appears (see combustion.rules for details). It is read and if
+the "network" flag comment is present, enables networking for later.
+After /sysroot is mounted and network is up (if enabled), combustion.service
+runs, which tries to activate all mountpoints in the system's /etc/fstab and
+then calls transactional-update in a chroot.
 
 In this transactional-update session the script is started and the exit code
 recorded. If the script failed, transactional-update rollback is called and

combustion

@@ -9,14 +9,37 @@ if [ "${1-}" = "--prepare" ]; then
 	# Mount config drive
 	mkdir -p "${config_mount}"
 
-	if ! [ -e /dev/disk/by-label/ignition ]; then
-		echo "No config drive found"
-		exit 0
+	config_drive_found=0
+
+	# Try fw_cfg first
+	if [ -e "/sys/firmware/qemu_fw_cfg/by_name/opt/org.opensuse.combustion" ]; then
+		mkdir -p "${config_mount}/combustion"
+		if ! cp /sys/firmware/qemu_fw_cfg/by_name/opt/org.opensuse.combustion/script/raw \
+		        "${config_mount}/combustion/script"; then
+			echo "Failed to copy script from fw_cfg!"
+			exit 1
+		fi
+		# TODO: Support other files, e.g. with a tarball or fs image?
+
+		config_drive_found=1
 	fi
 
-	if ! mount -o ro /dev/disk/by-label/ignition "${config_mount}"; then
-		echo "Failed to mount config drive!"
-		exit 1
+	# Try disks next
+	for label in combustion ignition; do
+		[ "${config_drive_found}" = "1" ] && break
+		[ -e "/dev/disk/by-label/${label}" ] || continue
+
+		if ! mount -o ro /dev/disk/by-label/${label} "${config_mount}"; then
+			echo "Failed to mount config drive!"
+			exit 1
+		fi
+
+                config_drive_found=1
+	done
+
+	if [ "${config_drive_found}" = "0" ]; then
+		echo "No config drive found"
+		exit 0
 	fi
 
 	# Check for the magic flag "# combustion: network" in the script
@@ -44,6 +67,8 @@ cleanup() {
 	if findmnt "${config_mount}" >/dev/null; then
 		umount "${config_mount}" || true
 		rmdir "${config_mount}" || true
+	else
+		rm -rf "${config_mount}" || true
 	fi
 
 	rm -rf "${exchangedir}" || true

combustion-prepare.service

@@ -2,11 +2,14 @@
 Description=Combustion (preparations)
 DefaultDependencies=false
 
-ConditionKernelCommandLine=ignition.firstboot
+# Systemd evaluates Requires/After before conditions, so this unit is pulled in
+# even when combustion.service won't run.
+ConditionKernelCommandLine=|ignition.firstboot
+ConditionKernelCommandLine=|combustion.firstboot
 
 # Config drive has to be available
-Wants=dev-disk-by\x2dlabel-ignition.device
-After=dev-disk-by\x2dlabel-ignition.device
+Wants=dev-combustion-config.device
+After=dev-combustion-config.device
 
 # If both Ignition and Combustion are active make sure to run their
 # configuration scripts sequentially, as both try to mount the configuration

combustion.changes

@@ -1,3 +1,16 @@
+-------------------------------------------------------------------
+Thu Sep 17 10:56:44 UTC 2020 - Fabian Vogt <fvogt@suse.com>
+
+- Overhaul configuration fetching:
+  * Add udev rules to wait for either ignition, combustion or
+    fw_cfg drives
+  * Allow combustion.firstboot in addition to ignition.firstboot
+  M combustion
+  A combustion-prepare.service
+  M combustion.service
+  M module-setup.sh
+- Bump version to 0.2
+
 -------------------------------------------------------------------
 Mon Sep 14 09:20:49 UTC 2020 - Ignaz Forster <iforster@suse.com>
 

combustion.rules

@@ -0,0 +1,27 @@
+# SPDX-FileCopyrightText: 2020 SUSE LLC
+# SPDX-License-Identifier: GPL-2.0-only
+
+# These rules are needed to work around two systemd limitations:
+# - It's not possible to wait for one of multiple devices to appear 
+# - ConditionKernelCommandLine is evaluated after Wants/After,
+#   so it waits for the devices unnecessarily
+# Introduce a dev-combustion-config.device unit as alias to the actual device(s).
+# This is only used for the .service dependencies.
+
+# Filesystems with either combustion or ignition as label
+ACTION=="add", SUBSYSTEM=="block", ENV{ID_FS_LABEL}=="combustion", ENV{SYSTEMD_ALIAS}+="/dev/combustion/config"
+ACTION=="add", SUBSYSTEM=="block", ENV{ID_FS_LABEL}=="ignition", ENV{SYSTEMD_ALIAS}+="/dev/combustion/config"
+# QEMU fw_cfg blob with key opt/org.opensuse.combustion
+ACTION=="add", SUBSYSTEM=="opt", ENV{DEVPATH}=="/firmware/qemu_fw_cfg/by_name/opt/org.opensuse.combustion", ENV{SYSTEMD_ALIAS}+="/dev/combustion/config", TAG+="systemd"
+
+# If combustion won't run, alias it to /dev/null to avoid waiting
+ACTION=="add", SUBSYSTEM=="mem", ENV{DEVPATH}=="/devices/virtual/mem/null", GOTO="combustion_dev_null"
+GOTO="combustion_end"
+
+LABEL="combustion_dev_null"
+# IMPORT has to be on its own as it returns success or not, even with "="...
+IMPORT{cmdline}="ignition.firstboot"
+IMPORT{cmdline}="combustion.firstboot"
+ENV{ignition.firstboot}!="1", ENV{combustion.firstboot}!="1", ENV{SYSTEMD_ALIAS}+="/dev/combustion/config", TAG+="systemd"
+
+LABEL="combustion_end"

combustion.service

@@ -2,7 +2,8 @@
 Description=Combustion
 DefaultDependencies=false
 
-ConditionKernelCommandLine=ignition.firstboot
+ConditionKernelCommandLine=|ignition.firstboot
+ConditionKernelCommandLine=|combustion.firstboot
 
 Requires=sysroot.mount
 After=sysroot.mount

combustion.spec

@@ -17,7 +17,7 @@
 
 
 Name:           combustion
-Version:        0.1
+Version:        0.2
 Release:        0
 Summary:        System for initial configuration of appliances
 License:        GPL-2.0-only
@@ -29,6 +29,7 @@ Source3:        module-setup.sh
 Source4:        combustion.service
 Source5:        combustion-prepare.service
 Source6:        combustion
+Source7:        combustion.rules
 Requires:       ignition-dracut-grub2
 BuildArch:      noarch
 
@@ -54,6 +55,7 @@ install -m0644 %{SOURCE3} module-setup.sh
 install -m0644 %{SOURCE4} combustion.service
 install -m0644 %{SOURCE5} combustion-prepare.service
 install -m0755 %{SOURCE6} combustion
+install -m0644 %{SOURCE7} combustion.rules
 
 %post
 %{?regenerate_initrd_post}

module-setup.sh

@@ -5,6 +5,7 @@ depends() {
 install() {
 	inst_simple "${moddir}/combustion.service" "${systemdsystemunitdir}/combustion.service"
 	inst_simple "${moddir}/combustion-prepare.service" "${systemdsystemunitdir}/combustion-prepare.service"
+	inst_simple "${moddir}/combustion.rules" "/etc/udev/rules.d/70-combustion.rules"
 	mkdir -p "${initdir}/${systemdsystemunitdir}/initrd.target.requires/"
 	ln_r "../combustion.service" "${systemdsystemunitdir}/initrd.target.requires/combustion.service"
 	inst_multiple awk chroot findmnt 
@@ -13,6 +14,6 @@ install() {
 	# Wait up to 10s (30s on aarch64) for the config drive
 	devtimeout=10
 	[ "$(uname -m)" = "aarch64" ] && devtimeout=30
-	mkdir -p "${initdir}/${systemdsystemunitdir}/dev-disk-by\x2dlabel-ignition.device.d/"
-	echo -e "[Unit]\nJobTimeoutSec=${devtimeout}" > "${initdir}/${systemdsystemunitdir}/dev-disk-by\x2dlabel-ignition.device.d/timeout.conf"
+	mkdir -p "${initdir}/${systemdsystemunitdir}/dev-combustion-config.device.d/"
+	echo -e "[Unit]\nJobTimeoutSec=${devtimeout}" > "${initdir}/${systemdsystemunitdir}/dev-combustion-config.device.d/timeout.conf"
 }