[bitnami/redis] Automatic labeling of master pod fails if useHostnames is set to false

[xTrekStorex]

Name and Version

bitnami/redis 20.0.5

What architecture are you using?

amd64

What steps will reproduce the bug?

• run chart with useHostnames=false (due to DNS issues causing tilt mode)
• enable sentinel
• enable masterService

Are you using any custom parameters or values?

useHostnames: false
sentinel:
  enabled: true
  masterService:
    enabled: true

What is the expected behavior?

master pod is labeled with isMaster="true"

What do you see instead?

no such label on master

Additional information

kubectl uses the content of /etc/shared/current for the pod selector in update-master-label.sh.
The content of /etc/shared/current is written by sentinel from ${REDIS_MASTER_HOST/.*} in start-sentinel.sh.
when using useHostnames=false REDIS_MASTER_HOST contains not redis-node-0.redis.svc.cluster.local, which would return redis-node-0 as current, but instead the IP address e.g. 172.22.140.140 which returns 172 as current.
thus kubectl matches no pod and updates no labels.
Unfortunately, the output of kubectl is also not logged - only the echo statement with new master elected, updating label(s)....
Patching the script configmap with echo "$(< "/etc/shared/current")" helped to debug this as it returned 172 instead of redis-node-0.

This also applies to the delete patch for the label app.kubernetes.io/role which will be fixed in 20.0.6 (annotation -> label).

To fix this either sentinel writes a non-resolved value for REDIS_MASTER_HOST into /etc/shared/current
or the kubectl script looks up the pod by IP if current is numerical. such as:
kubectl get -n <namespace> --output json pods | jq '.items[] | select(.status.podIP=="<IP>")' | jq .metadata.name
though this would likely require further RBAC permissions.

[carrodher]

Thank you for bringing this issue to our attention. We appreciate your involvement! If you're interested in contributing a solution, we welcome you to create a pull request. The Bitnami team is excited to review your submission and offer feedback. You can find the contributing guidelines here.

Your contribution will greatly benefit the community. Feel free to reach out if you have any questions or need assistance.

[github-actions]

This Issue has been automatically marked as "stale" because it has not had recent activity (for 15 days). It will be closed if no further activity occurs. Thanks for the feedback.

[github-actions]

Due to the lack of activity in the last 5 days since it was marked as "stale", we proceed to close this Issue. Do not hesitate to reopen it later if necessary.