Adding support for custom SEL records

[Brad Bishop]

Thanks Lei YU for adding the support desribed below.  Sorry for the
necropost but I had a couple questions (below) for anyone that feels
like indulging me with answers.

On Mon, 2020-12-07 at 15:35 +0800, Lei Yu wrote:
> This mail is to propose some changes in openbmc to support custom SEL
> records.
> 
> * Background
> The phosphor-sel-logger is the service to provide methods (IpmiSelAdd,
> IpmiSelAddOem) to add custom SEL records.
> However:
> 1. It only sends the log into the journal;
> 2. It depends on
> meta-intel/meta-common/recipes-extended/rsyslog/rsyslog/rsyslog.conf
> to filter the journal log and write to "/var/log/ipmi_sel"
> 3. It depends on intel-ipmi-oem to parse the "/var/log/ipmi_sel" to
> provide the SEL entries.
> 
> In short, phosphor-sel-logger only works with the meta-intel layer and
> intel-ipmi-oem.
> 
> To make it support general usage, several changes are submitted to
> gerrit:
> https://gerrit.openbmc-project.xyz/q/topic:%22dev-add-custom-sel%22+(status:open%20OR%20status:merged)

To make it support general usage, I think we could have just moved the
rsyslog.conf to meta-phosphor and moved the handlers from intel-ipmi-oem
to phosphor-host-ipmid, correct?  Instead, we invented something
completely new.  My question is, why?

Whatever the reason, OpenBMC now has two ways of doing SELs, and I am
tasked with picking one.  Knowing what was wrong with the rsyslog 
approach that led you to invent something new to replace it would help
me, (and others I suspect), make that decision.

Thanks!
brad