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Diffstat (limited to 'meta/classes/overlayfs.bbclass')
| -rw-r--r-- | meta/classes/overlayfs.bbclass | 131 |
1 files changed, 0 insertions, 131 deletions
diff --git a/meta/classes/overlayfs.bbclass b/meta/classes/overlayfs.bbclass deleted file mode 100644 index f7069edd41..0000000000 --- a/meta/classes/overlayfs.bbclass +++ /dev/null @@ -1,131 +0,0 @@ -# Class for generation of overlayfs mount units -# -# It's often desired in Embedded System design to have a read-only rootfs. -# But a lot of different applications might want to have a read-write access to -# some parts of a filesystem. It can be especially useful when your update mechanism -# overwrites the whole rootfs, but you want your application data to be preserved -# between updates. This class provides a way to achieve that by means -# of overlayfs and at the same time keeping the base rootfs read-only. -# -# Usage example. -# -# Set a mount point for a partition overlayfs is going to use as upper layer -# in your machine configuration. Underlying file system can be anything that -# is supported by overlayfs. This has to be done in your machine configuration. -# QA check fails to catch file existence if you redefine this variable in your recipe! -# -# OVERLAYFS_MOUNT_POINT[data] ?= "/data" -# -# Per default the class assumes you have a corresponding fstab entry or systemd -# mount unit (data.mount in this case) for this mount point installed on the -# image, for instance via a wks script or the systemd-machine-units recipe. -# -# If the mount point is handled somewhere else, e.g. custom boot or preinit -# scripts or in a initramfs, then this QA check can be skipped by adding -# mount-configured to the related OVERLAYFS_QA_SKIP flag: -# -# OVERLAYFS_QA_SKIP[data] = "mount-configured" -# -# To use the overlayfs, you just have to specify writable directories inside -# their recipe: -# -# OVERLAYFS_WRITABLE_PATHS[data] = "/usr/share/my-custom-application" -# -# To support several mount points you can use a different variable flag. Assume we -# want to have a writable location on the file system, but not interested where the data -# survive a reboot. Then we could have a mnt-overlay.mount unit for a tmpfs file system: -# -# OVERLAYFS_MOUNT_POINT[mnt-overlay] = "/mnt/overlay" -# OVERLAYFS_WRITABLE_PATHS[mnt-overlay] = "/usr/share/another-application" -# -# If your recipe deploys a systemd service, then it should require and be -# started after the ${PN}-overlays.service to make sure that all overlays are -# mounted beforehand. -# -# Note: the class does not support /etc directory itself, because systemd depends on it -# For /etc directory use overlayfs-etc class - -REQUIRED_DISTRO_FEATURES += "systemd overlayfs" - -inherit systemd features_check - -OVERLAYFS_CREATE_DIRS_TEMPLATE ??= "${COREBASE}/meta/files/overlayfs-create-dirs.service.in" -OVERLAYFS_MOUNT_UNIT_TEMPLATE ??= "${COREBASE}/meta/files/overlayfs-unit.mount.in" -OVERLAYFS_ALL_OVERLAYS_TEMPLATE ??= "${COREBASE}/meta/files/overlayfs-all-overlays.service.in" - -python do_create_overlayfs_units() { - from oe.overlayfs import mountUnitName - - with open(d.getVar("OVERLAYFS_CREATE_DIRS_TEMPLATE"), "r") as f: - CreateDirsUnitTemplate = f.read() - with open(d.getVar("OVERLAYFS_MOUNT_UNIT_TEMPLATE"), "r") as f: - MountUnitTemplate = f.read() - with open(d.getVar("OVERLAYFS_ALL_OVERLAYS_TEMPLATE"), "r") as f: - AllOverlaysTemplate = f.read() - - def prepareUnits(data, lower): - from oe.overlayfs import helperUnitName - - args = { - 'DATA_MOUNT_POINT': data, - 'DATA_MOUNT_UNIT': mountUnitName(data), - 'CREATE_DIRS_SERVICE': helperUnitName(lower), - 'LOWERDIR': lower, - } - - bb.debug(1, "Generate systemd unit %s" % mountUnitName(lower)) - with open(os.path.join(d.getVar('WORKDIR'), mountUnitName(lower)), 'w') as f: - f.write(MountUnitTemplate.format(**args)) - - bb.debug(1, "Generate helper systemd unit %s" % helperUnitName(lower)) - with open(os.path.join(d.getVar('WORKDIR'), helperUnitName(lower)), 'w') as f: - f.write(CreateDirsUnitTemplate.format(**args)) - - def prepareGlobalUnit(dependentUnits): - from oe.overlayfs import allOverlaysUnitName - args = { - 'ALL_OVERLAYFS_UNITS': " ".join(dependentUnits), - 'PN': d.getVar('PN') - } - - bb.debug(1, "Generate systemd unit with all overlays %s" % allOverlaysUnitName(d)) - with open(os.path.join(d.getVar('WORKDIR'), allOverlaysUnitName(d)), 'w') as f: - f.write(AllOverlaysTemplate.format(**args)) - - mountUnitList = [] - overlayMountPoints = d.getVarFlags("OVERLAYFS_MOUNT_POINT") - for mountPoint in overlayMountPoints: - bb.debug(1, "Process variable flag %s" % mountPoint) - for lower in d.getVarFlag('OVERLAYFS_WRITABLE_PATHS', mountPoint).split(): - bb.debug(1, "Prepare mount unit for %s with data mount point %s" % - (lower, d.getVarFlag('OVERLAYFS_MOUNT_POINT', mountPoint))) - prepareUnits(d.getVarFlag('OVERLAYFS_MOUNT_POINT', mountPoint), lower) - mountUnitList.append(mountUnitName(lower)) - - # set up one unit, which depends on all mount units, so users can set - # only one dependency in their units to make sure software starts - # when all overlays are mounted - prepareGlobalUnit(mountUnitList) -} - -# we need to generate file names early during parsing stage -python () { - from oe.overlayfs import strForBash, unitFileList - - unitList = unitFileList(d) - for unit in unitList: - d.appendVar('SYSTEMD_SERVICE:' + d.getVar('PN'), ' ' + unit) - d.appendVar('FILES:' + d.getVar('PN'), ' ' + - d.getVar('systemd_system_unitdir') + '/' + strForBash(unit)) - - d.setVar('OVERLAYFS_UNIT_LIST', ' '.join([strForBash(s) for s in unitList])) -} - -do_install:append() { - install -d ${D}${systemd_system_unitdir} - for unit in ${OVERLAYFS_UNIT_LIST}; do - install -m 0444 ${WORKDIR}/${unit} ${D}${systemd_system_unitdir} - done -} - -addtask create_overlayfs_units before do_install |