[ClusterLabs] related to fencing in general , docker containers

[Ken Gaillot]

On Fri, 2022-06-17 at 17:59 +0300, Andrei Borzenkov wrote:
> On 17.06.2022 16:53, Sridhar K wrote:
> > Hi Team,
> > 
> > Please share any pointers, references, example usage's w.r.t
> > fencing in
> > general and its use w.r.t docker containers.
> > 
> > referring as of now
> > https://clusterlabs.org/pacemaker/doc/crm_fencing.html

FYI that document is quite dated, and the syntax is all wrong, but the
basic concepts are still valid. The more up-to-date documentation is:

https://clusterlabs.org/pacemaker/doc/2.1/Pacemaker_Explained/singlehtml/index.html#document-fencing

with an example at:

https://clusterlabs.org/pacemaker/doc/2.1/Clusters_from_Scratch/singlehtml/index.html#document-fencing

> > 
> > need to check the feasibility of fencing w.r.t docker containers
> > 
> 
> There is fence_docker, you will need to configure docker on each
> physical host to accept remote connections from each cluster node.
> You
> will probably need one fencing agent for each physical host where
> docker
> is running and map cluster nodes (containers) to the correct agent
> (i.e.
> physical host).

I guess the first question is how you plan to use containers. Are you
planning on containerizing the cluster stack itself (corosync and
pacemaker), using containers as Pacemaker Remote nodes, or simply
launching containers that run resources?

If you plan to have non-containerized cluster nodes, and just want to
run resources inside containers, then bundles are your best bet:

https://clusterlabs.org/pacemaker/doc/2.1/Pacemaker_Explained/singlehtml/index.html#bundles-containerized-resources
-- 
Ken Gaillot <kgaillot at redhat.com>