[OE-core] [PATCH] sysklogd: add alternatives for klogd and syslogd

[ChenQi]

On 10/26/2018 12:53 PM, Victor Kamensky via Openembedded-core wrote:
> Otherwise when used in presense of busybox that provides
> its own version of klogd and syslogd, image packaging
> complains that klogd exists and it is not syymbolic link.
> Failure happens only if image packaging script install
> sysklogd package first followed by installtion of busybox
> package.

Hi Victor,

I think this problem has been fixed by the following commit.

"""
commit ef11c54ba99af261a70ec31091216cdd1556da24
Author: Richard Purdie <richard.purdie at linuxfoundation.org>
Date:   Wed Sep 5 17:39:31 2018 +0100

     busybox: Put klogd/syslogd alternative links in syslog package

     Currently these are in ${PN} and ${PN}-syslog may get replaced by
     other packages but update-alternatives would error in the postinst
     if other files were installed first. Avoid the problems by putting
     the links in the correct package.

     Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>
"""

For the current status, the update-alternatives operations for syslogd 
and klogd should be in the busybox-syslog package, which conflicts with 
sysklogd package.

Could you please help check this?

Best Regards,
Chen Qi

>   If during packaging reverse installtion order
> happens, busybox first followed by sysklogd, packaging
> succeed.
>
> Note this fix along with recently committed
> 55ba9dc1f8 sysklogd: Re-enable alternatives for syslogd.8 man page
> effectively reverts this commit
> 988aad01b2 sysklogd: don't use update-alternatives
>
> Signed-off-by: Victor Kamensky <kamensky at cisco.com>
> ---
> Hi Guys,
>
> Here is more details. Example of failure that I observe:
>
> update-alternatives: Error: not linking /home/wd8/oe/20181021/build/tmp-glibc/work/intel_corei7_64-oe-linux/kdevel-console-devel-image/1.0-r0/rootfs/sbin/klogd to /usr/lib/busybox/sbin/klogd since /home/wd8/oe/20181021/build/tmp-glibc/work/intel_corei7_64-oe-linux/kdevel-console-devel-image/1.0-r0/rootfs/sbin/klogd exists and is not a link
>
> Also 988aad01b2 says:
>
>> Using update-alternatives for managing init scripts has proved to be
>> problematic. And, sysklogd rconflicts with other syslog daemons so there
>> is no point in using update-alternatives from this perspective, either.
> I am not sure why "managing init scripts has proved to be problematic" and
> syslogd and klogd are not really init script per se, aren't they? Also
> klogd and syslogd actually come from busybox, not busybox-syslog as listed
> in sysklogd RCONFLICTS. Maybe it what has changed since 988aad01b2.
> busybox-syslog now contains only init script for syslog and its
> configuration.
>
> Adding Markus for further comments.
>
>   meta/recipes-extended/sysklogd/sysklogd.inc | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/meta/recipes-extended/sysklogd/sysklogd.inc b/meta/recipes-extended/sysklogd/sysklogd.inc
> index f151dd87f7..4393a39180 100644
> --- a/meta/recipes-extended/sysklogd/sysklogd.inc
> +++ b/meta/recipes-extended/sysklogd/sysklogd.inc
> @@ -60,9 +60,14 @@ FILES_${PN} += "${@bb.utils.contains('DISTRO_FEATURES','systemd','${exec_prefix}
>   
>   ALTERNATIVE_PRIORITY = "100"
>   
> +ALTERNATIVE_${PN} = "syslogd klogd"
> +
>   ALTERNATIVE_${PN}-doc = "syslogd.8"
>   ALTERNATIVE_LINK_NAME[syslogd.8] = "${mandir}/man8/syslogd.8"
>   
> +ALTERNATIVE_LINK_NAME[syslogd] = "${base_sbindir}/syslogd"
> +ALTERNATIVE_LINK_NAME[klogd] = "${base_sbindir}/klogd"
> +
>   pkg_prerm_${PN} () {
>   	if test "x$D" = "x"; then
>   	if test "$1" = "upgrade" -o "$1" = "remove"; then