From ce65ac2dd1d78ff0498e7ad84be833df81935380 Mon Sep 17 00:00:00 2001 From: Claudius Heine Date: Tue, 10 May 2022 09:48:51 +0200 Subject: overlayfs: add docs about skipping QA check & service dependencies Add some documentation about skipping the QA check related to missing fstab entries or mount units for base mount points where the overlayfs is mounted from. Also add a short paragraph about adding a systemd unit dependency to services in recipes, so that they are started only after the overlayfs is mounted and ready. No functional change. (From OE-Core rev: 7adc49fa6fdbdf118f74e95193e80ae7ef019e27) Signed-off-by: Claudius Heine Signed-off-by: Luca Ceresoli Signed-off-by: Richard Purdie --- meta/classes/overlayfs.bbclass | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/meta/classes/overlayfs.bbclass b/meta/classes/overlayfs.bbclass index 29fced2ca7..f7069edd41 100644 --- a/meta/classes/overlayfs.bbclass +++ b/meta/classes/overlayfs.bbclass @@ -16,10 +16,18 @@ # # OVERLAYFS_MOUNT_POINT[data] ?= "/data" # -# The class assumes you have a data.mount systemd unit defined in your -# systemd-machine-units recipe and installed to the image. +# 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. # -# Then you can specify writable directories on a recipe base +# 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" # @@ -30,6 +38,10 @@ # 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 -- cgit v1.2.3-54-g00ecf