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author | Vyacheslav Yurkov <uvv.mail@gmail.com> | 2021-12-10 14:01:39 +0100 |
---|---|---|
committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2021-12-12 11:27:24 +0000 |
commit | 8ac91c0c0dccfdeae9d0bebb5857826b91d40dda (patch) | |
tree | 17f592264cc889f29c497ab5588705e81ac0b2f8 /meta | |
parent | 822adf5c9f84062867988c903170156d94ee3729 (diff) | |
download | poky-8ac91c0c0dccfdeae9d0bebb5857826b91d40dda.tar.gz |
overlayfs-etc: mount etc as overlayfs
This class provides an image feature that mounts /etc as an overlayfs
file system. This is an extension for existing overlayfs class, which
doesn't support /etc
(From OE-Core rev: 610ea808c8b5edb2826bda1f1c42a811bd4ba758)
Signed-off-by: Alfred Schapansky <alfred.schapansky@avantys.de>
Signed-off-by: Vyacheslav Yurkov <uvv.mail@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'meta')
-rw-r--r-- | meta/classes/overlayfs-etc.bbclass | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/meta/classes/overlayfs-etc.bbclass b/meta/classes/overlayfs-etc.bbclass new file mode 100644 index 0000000000..4ced07ba11 --- /dev/null +++ b/meta/classes/overlayfs-etc.bbclass | |||
@@ -0,0 +1,76 @@ | |||
1 | # Class for setting up /etc in overlayfs | ||
2 | # | ||
3 | # In order to have /etc directory in overlayfs a special handling at early boot stage is required | ||
4 | # The idea is to supply a custom init script that mounts /etc before launching actual init program, | ||
5 | # because the latter already requires /etc to be mounted | ||
6 | # | ||
7 | # The configuration must be machine specific. You should at least set these three variables: | ||
8 | # OVERLAYFS_ETC_MOUNT_POINT ?= "/data" | ||
9 | # OVERLAYFS_ETC_FSTYPE ?= "ext4" | ||
10 | # OVERLAYFS_ETC_DEVICE ?= "/dev/mmcblk0p2" | ||
11 | # | ||
12 | # To control more mount options you should consider setting mount options: | ||
13 | # OVERLAYFS_ETC_MOUNT_OPTIONS ?= "defaults" | ||
14 | # | ||
15 | # The class provides two options for /sbin/init generation | ||
16 | # 1. Default option is to rename original /sbin/init to /sbin/init.orig and place generated init under | ||
17 | # original name, i.e. /sbin/init. It has an advantage that you won't need to change any kernel | ||
18 | # parameters in order to make it work, but it poses a restriction that package-management can't | ||
19 | # be used, becaause updating init manager would remove generated script | ||
20 | # 2. If you are would like to keep original init as is, you can set | ||
21 | # OVERLAYFS_ETC_USE_ORIG_INIT_NAME = "0" | ||
22 | # Then generated init will be named /sbin/preinit and you would need to extend you kernel parameters | ||
23 | # manually in your bootloader configuration. | ||
24 | # | ||
25 | # Regardless which mode you choose, update and migration strategy of configuration files under /etc | ||
26 | # overlay is out of scope of this class | ||
27 | |||
28 | ROOTFS_POSTPROCESS_COMMAND += '${@bb.utils.contains("IMAGE_FEATURES", "overlayfs-etc", "create_overlayfs_etc_preinit;", "", d)}' | ||
29 | IMAGE_FEATURES_CONFLICTS_overlayfs-etc = "package-management" | ||
30 | |||
31 | OVERLAYFS_ETC_MOUNT_POINT ??= "" | ||
32 | OVERLAYFS_ETC_FSTYPE ??= "" | ||
33 | OVERLAYFS_ETC_DEVICE ??= "" | ||
34 | OVERLAYFS_ETC_USE_ORIG_INIT_NAME ??= "1" | ||
35 | OVERLAYFS_ETC_MOUNT_OPTIONS ??= "defaults" | ||
36 | OVERLAYFS_ETC_INIT_TEMPLATE ??= "${COREBASE}/meta/files/overlayfs-etc-preinit.sh.in" | ||
37 | |||
38 | python create_overlayfs_etc_preinit() { | ||
39 | overlayEtcMountPoint = d.getVar("OVERLAYFS_ETC_MOUNT_POINT") | ||
40 | overlayEtcFsType = d.getVar("OVERLAYFS_ETC_FSTYPE") | ||
41 | overlayEtcDevice = d.getVar("OVERLAYFS_ETC_DEVICE") | ||
42 | |||
43 | if not overlayEtcMountPoint: | ||
44 | bb.fatal("OVERLAYFS_ETC_MOUNT_POINT must be set in your MACHINE configuration") | ||
45 | if not overlayEtcDevice: | ||
46 | bb.fatal("OVERLAYFS_ETC_DEVICE must be set in your MACHINE configuration") | ||
47 | if not overlayEtcFsType: | ||
48 | bb.fatal("OVERLAYFS_ETC_FSTYPE should contain a valid file system type on {0}".format(overlayEtcDevice)) | ||
49 | |||
50 | with open(d.getVar("OVERLAYFS_ETC_INIT_TEMPLATE"), "r") as f: | ||
51 | PreinitTemplate = f.read() | ||
52 | |||
53 | useOrigInit = oe.types.boolean(d.getVar('OVERLAYFS_ETC_USE_ORIG_INIT_NAME')) | ||
54 | preinitPath = oe.path.join(d.getVar("IMAGE_ROOTFS"), d.getVar("base_sbindir"), "preinit") | ||
55 | initBaseName = oe.path.join(d.getVar("base_sbindir"), "init") | ||
56 | origInitNameSuffix = ".orig" | ||
57 | |||
58 | args = { | ||
59 | 'OVERLAYFS_ETC_MOUNT_POINT': overlayEtcMountPoint, | ||
60 | 'OVERLAYFS_ETC_MOUNT_OPTIONS': d.getVar('OVERLAYFS_ETC_MOUNT_OPTIONS'), | ||
61 | 'OVERLAYFS_ETC_FSTYPE': overlayEtcFsType, | ||
62 | 'OVERLAYFS_ETC_DEVICE': overlayEtcDevice, | ||
63 | 'SBIN_INIT_NAME': initBaseName + origInitNameSuffix if useOrigInit else initBaseName | ||
64 | } | ||
65 | |||
66 | if useOrigInit: | ||
67 | # rename original /sbin/init | ||
68 | origInit = oe.path.join(d.getVar("IMAGE_ROOTFS"), initBaseName) | ||
69 | bb.debug(1, "rootfs path %s, init path %s, test %s" % (d.getVar('IMAGE_ROOTFS'), origInit, d.getVar("IMAGE_ROOTFS"))) | ||
70 | bb.utils.rename(origInit, origInit + origInitNameSuffix) | ||
71 | preinitPath = origInit | ||
72 | |||
73 | with open(preinitPath, 'w') as f: | ||
74 | f.write(PreinitTemplate.format(**args)) | ||
75 | os.chmod(preinitPath, 0o755) | ||
76 | } | ||