Bug 1774888

With the planned changes in crm_mon we can reliably display status of resources in the 'pcs resource status' command: ask crm_mon to return just resources instead of parsing its whole plaintext output in pcs. We still need to keep the old code for compatibility with old pacemaker versions.


+++ This bug was initially created as a clone of Bug #1363907 +++

+++ This bug was initially created as a clone of Bug #1361533 +++

--- Additional comment from Tomas Jelinek on 2016-08-03 07:09:39 EDT ---

(In reply to Ken Gaillot from comment #3)
> I'll try to fix the header issue for 7.3, but understand that the console
> output changes from one pacemaker version to another, so it can't be relied
> on in the long term.
> 
> Is your goal to display only certain sections of the crm_mon output? For
> example, just the resources, or just the resources and the failcounts. If

yes

> that's the case, I have an idea for an enhancement that could make it into
> 7.4. We could add an --include option to crm_mon that would take a
> comma-separated list of sections you want to display. E.g. "crm_mon
> --include resources,failcounts". Would that be sufficient?

That would be great!

--- Additional comment from Ken Gaillot on 2019-11-20 16:59:14 CET ---

To summarize the current plan, the following design will take care of this bz, Bug 1300597, and Bug 1300604:

crm_mon will gain new "--include" and "--exclude" options to select what sections are shown. For example, to show only the top summary and the nodes status, you could use "crm_mon --include=none,summary,nodes". Or to show just the resources section, you could use "crm_mon --include=none,resources". (The "none" is to clear the defaults. You could equally keep the defaults and use "--exclude" to specify everything you don't want to see.)

Some of these section names will take an optional qualifier as "SECTION:QUALIFIER". For "nodes" and "resources", this qualifier will be an XML ID, either of a particular node or resource, or of a tag. When a qualifier is given, crm_mon will show only the requested nodes and/or resources.

For example, to show just the status of node1, you could use "crm_mon --include=none,nodes:node1". Or just the status of rsc1, "crm_mon --include=none,resources:rsc1".

For an explanation of how tagging works in the Pacemaker configuration, see the "Tagging configuration elements" section of the upstream "Pacemaker Explained" documentation:

    https://clusterlabs.org/pacemaker/doc/en-US/Pacemaker/2.0/html-single/Pacemaker_Explained/index.html#_tagging_configuration_elements

pcs will need the ability to set tags (Bug 1684676) as well as new options to use this new selection syntax.