[Buildroot] [PATCH 03/16] package/dbus: fix machine-id when using systemd

[Samuel Martin]

Hi Maxim,

On Mon, Jan 19, 2015 at 5:14 PM, Maxim Mikityanskiy <maxtram95 at gmail.com> wrote:
> When systemd is used, /var/lib/dbus becomes dangling symlink, because
> nobody does mkdir /tmp/dbus, so /var/lib/dbus/machine-id could not be
> written. On SysVinit systems there is init script that creates
> /tmp/dbus.

Maybe we should add /tmp/dbus to a tmpfiles config file (see [1]).

>
> This patch preserves old behavior for SysVinit systems, and introduces
> new one for systemd-booted systems: /var/lib/dbus is a persistent
> directory, it holds symlink /var/lib/dbus/machine-id -> /etc/machine-id
> as machine-id(5) suggests, and /etc/machine-id is managed by systemd.

This assumes that /etc is witable... which is not necessary the case :-/

>
> Signed-off-by: Maxim Mikityanskiy <maxtram95 at gmail.com>
> ---
>  package/dbus/dbus.mk | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/package/dbus/dbus.mk b/package/dbus/dbus.mk
> index faad2b5..266e27b 100644
> --- a/package/dbus/dbus.mk
> +++ b/package/dbus/dbus.mk
> @@ -73,17 +73,18 @@ endef
>
>  DBUS_POST_INSTALL_TARGET_HOOKS += DBUS_REMOVE_DEVFILES
>
> -define DBUS_INSTALL_TARGET_FIXUP
> +define DBUS_INSTALL_INIT_SYSV
> +       $(INSTALL) -m 0755 -D package/dbus/S30dbus \
> +               $(TARGET_DIR)/etc/init.d/S30dbus
> +
>         mkdir -p $(TARGET_DIR)/var/lib
>         rm -rf $(TARGET_DIR)/var/lib/dbus
>         ln -sf /tmp/dbus $(TARGET_DIR)/var/lib/dbus
>  endef
>
> -DBUS_POST_INSTALL_TARGET_HOOKS += DBUS_INSTALL_TARGET_FIXUP
> -
> -define DBUS_INSTALL_INIT_SYSV
> -       $(INSTALL) -m 0755 -D package/dbus/S30dbus \
> -               $(TARGET_DIR)/etc/init.d/S30dbus
> +define DBUS_INSTALL_INIT_SYSTEMD
> +       mkdir -p $(TARGET_DIR)/var/lib/dbus
> +       ln -sf /etc/machine-id $(TARGET_DIR)/var/lib/dbus/machine-id
>  endef
>
>  HOST_DBUS_DEPENDENCIES = host-pkgconf host-expat
> --
> 2.2.1

I'd prefer keeping the filesystem layout as close as possible between
sysVinit and systemd.
So, adding a symlink /etc/machine-id pointing to
/var/lib/dbus/machine-id (which will ends up in /tmp/dbus/machine-id
thanks to the tmpfiles.d stuff) should be enough.

Then the last thing to check is that systemd-machine-id-setup
correctly generates the machine-id file even if /etc/machine-id is a
symlink pointing to a non-existing file.

[1] http://www.freedesktop.org/software/systemd/man/tmpfiles.d.html

Regards,

-- 
Samuel