ha: anti-affnity rules are too restrictive #3939
Description
Linkerd, installed with --ha on a 3-node cluster, cannot be successfully upgraded:
:; kubectl get events -n linkerd
LAST SEEN TYPE REASON OBJECT MESSAGE
94s Warning FailedScheduling pod/linkerd-controller-c845b4549-wbz2d 0/3 nodes are available: 3 node(s) didn't match pod affinity/anti-affinity, 3 node(s) didn't satisfy existing pods anti-affinity rules.
94s Warning FailedScheduling pod/linkerd-destination-6488b657b-5srp8 0/3 nodes are available: 3 node(s) didn't match pod affinity/anti-affinity, 3 node(s) didn't satisfy existing pods anti-affinity rules.
94s Warning FailedScheduling pod/linkerd-identity-7dc5d97cf9-rxnz2 0/3 nodes are available: 3 node(s) didn't match pod affinity/anti-affinity, 3 node(s) didn't satisfy existing pods anti-affinity rules.
94s Warning FailedScheduling pod/linkerd-proxy-injector-64d8d46794-lb69h 0/3 nodes are available: 3 node(s) didn't match pod affinity/anti-affinity, 3 node(s) didn't satisfy existing pods anti-affinity rules.
94s Warning FailedScheduling pod/linkerd-sp-validator-86bbcbfbff-sldx6 0/3 nodes are available: 3 node(s) didn't match pod affinity/anti-affinity, 3 node(s) didn't satisfy existing pods anti-affinity rules.
94s Warning FailedScheduling pod/linkerd-tap-c895b586d-ps22z 0/3 nodes are available: 3 node(s) didn't match pod affinity/anti-affinity, 3 node(s) didn't satisfy existing pods anti-affinity rules.
@grampelberg suggests that this can be resolved with the following:
- define a PDB - https://kubernetes.io/docs/tasks/run-application/configure-pdb/#specifying-a-poddisruptionbudget
- set progressDeadlineSeconds
- define maxUnavailable
- configure maxSurge