With this modification is guaranteed that at least 1 MDS pod is going to be
placed in each of the available zones in the k8s cluster.
This would be improved in the future using:
<Pod Topology Spread Constraints> (still in alpha state since kubernetes V.1.16)
This modification obtain the number of zones in the k8s cluster and appends an
<antiaffinity> term using the topologyKey
<topology.kubernetes.io/zone> in the same number of MDS pods.
In the case that will be more MDS pods than zones, the <antiaffinity> term won't
be added in these extra pods.
Important Note:
The antiaffiniy term only will work with nodes labeled using the NEW label:
<topology.kubernetes.io/zone> present in k8s V.1.17 clusters.
For previous versions of k8s clusters the label used is:
<failure-domain.beta.kubernetes.io/zone>
And therefore, in this kind of clusters this modification won't work.
Resolves#4641
[test ceph]
Signed-off-by: Juan Miguel Olmo Martínez <jolmomar@redhat.com>
Juan Miguel Olmo Martínez
f62b2fa305