Integrate collectd with OpenBMC

[Brad Bishop]

On Thu, Jun 27, 2019 at 10:51:03PM -0700, Kun Yi wrote:
>Hello there,
>
>In the context of reporting BMC performance metrics, my intern Gabriel
>(cc'ed here) and I have started looking at integrating collectd as a
>metrics collection tool on OpenBMC. We have got it running, which is
>trivial, but the next question is how to report the data.
>
>We have thought about it and thinks implementing a D-Bus interface to be
>the most flexible approach. At first, we could implement a snapshot
>(instantaneos read) interface. It would then be fairly straightforward to
>add them as Redfish/IPMI sensors.

Just curious in what situations DBus was required?  In the design I 
thought you had applications going right to librrd - where did that fall 
down?

>
>There are two ways to do this:
>1. Implement as a collectd "D-Bus" plugin [1]. Collectd supports writing
>custom plugins which are C files calling the internal plugin APIs. Could
>probably use sdbus to implement.
>
>+ could potentially be upstreamed to collectd
>- the code probably will live in a downstream fork first, and if it doesn't
>end up upstream, maintaining could become an issue since collectd plugin
>API is not guaranteed stable
>- C
>
>2. Implement as an interposer daemon that translates between one of the
>formats that collectd supports (unix socket, plaintext, RRDTool..) to D-Bus
>
>+ project could be purely OpenBMC
>+ can use sdbusplus
>- another daemon
>
>Any advice on this? Currently we are leaning towards the first approach,
>but do you agree the D-Bus plugin is general enough to be of interest to
>the upstream collectd community?
>
>I can definitely reach out to the collectd group but just want to ask here
>first :)
>
>[1] Collectd plugins:
>https://collectd.org/wiki/index.php/Plugin_architecture
>-- 
>Regards,
>Kun