[Buildroot] [PATCH 1/6 v3] package/skeleton-systemd: move /var factory tmpfiles out of /etc

[Yann E. MORIN]

Norbert, All,

On 2022-11-06 16:40 +0100, Norbert Lange spake thusly:
> Am Di., 18. Okt. 2022 um 21:43 Uhr schrieb <yann.morin at orange.com>:
[--SNIP--]
> > diff --git a/package/skeleton-init-systemd/skeleton-init-systemd.mk b/package/skeleton-init-systemd/skeleton-init-systemd.mk
> > index 795a171809..7b66732ef4 100644
> > --- a/package/skeleton-init-systemd/skeleton-init-systemd.mk
> > +++ b/package/skeleton-init-systemd/skeleton-init-systemd.mk
> > @@ -29,7 +29,6 @@ else
> >  # a real (but empty) directory, and the "factory files" will be copied
> >  # back there by the tmpfiles.d mechanism.
> >  define SKELETON_INIT_SYSTEMD_ROOT_RO_OR_RW
> > -       mkdir -p $(TARGET_DIR)/etc/systemd/tmpfiles.d
> >         echo "/dev/root / auto ro 0 1" >$(TARGET_DIR)/etc/fstab
> >         echo "tmpfs /var tmpfs mode=1777 0 0" >>$(TARGET_DIR)/etc/fstab
> >  endef
> > @@ -38,6 +37,7 @@ define SKELETON_INIT_SYSTEMD_PRE_ROOTFS_VAR
> >         rm -rf $(TARGET_DIR)/usr/share/factory/var
> >         mv $(TARGET_DIR)/var $(TARGET_DIR)/usr/share/factory/var
> >         mkdir -p $(TARGET_DIR)/var
> > +       mkdir -p $(TARGET_DIR)/usr/lib/tmpfiles.d
> >         for i in $(TARGET_DIR)/usr/share/factory/var/* \
> >                  $(TARGET_DIR)/usr/share/factory/var/lib/* \
> >                  $(TARGET_DIR)/usr/share/factory/var/lib/systemd/*; do \
> > @@ -51,7 +51,7 @@ define SKELETON_INIT_SYSTEMD_PRE_ROOTFS_VAR
> >                         printf "C! %s - - - -\n" "$${j}" \
> >                         || exit 1; \
> >                 fi; \
> 
> From tmpfiles.d docs: "C ... Recursively copy a file or directory, if
> the destination files or directories do not
>   exist yet or the destination directory is empty. Note that this
> command will not descend into subdirectories
>   if the destination directory already exists and is not empty.
> Instead, the entire copy operation is skipped."
> 
> So all the drama could be just replaced with "C! /var - - - -\n" imho.
> 
> (non standard permissions/owner are probably gone either way)

I do remember that I had to explicitly register individual entries
rather than the directory alone, as that did not work. That was 5+
years ago (commit 26085bbbd500), and I did not write it down in the
commit log...

However, it looks like we hit this issue, as hinted in commit
7e811708f31c (package/skeleton-init-systemd: work around for /var/lib
not populating), which states:

    It turns out /var/lib will exist, because some part of systemd creates
    /var/lib/systemd/catalog on boot before tmpfiles runs.

So, we do have a chicken-n-eggs issue, that registering /var as a whole
does not work.

I'll try to investigate further, and see if that's still the case.

> > -       done >$(TARGET_DIR)/etc/tmpfiles.d/var-factory.conf
> > +       done >$(TARGET_DIR)/usr/lib/tmpfiles.d/buildroot-factory.conf
> 
> How about naming this something like 00-buildroot-var.conf, so hopefully any
> *.conf that might expect something in /var existing is executed later.

I am totally OK for 00-buildroot-var.conf.

[--SNIP--]
> Regardless, the changes are an improvement, buildroot is the "distro"
> and its special sauce
> should reside inside /usr as much as possible.

Yes, that was my reasoning as well.

> Id highly recommend atleast changing the name to
> 00-buildroot-var.conf, other than that:

Agreed.

> Acked-by: Norbert Lange <nolange79 at gmail.com>

Thanks!

Regards,
Yann E. MORIN.

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