In a k8s cluster, installed using the helm chart, how can I change the alpha configuration without reinstalling?

[joaquin (Joaquin Menchaca)]

@martaver

Is there a better, recommended way of getting the alpha nodes to re-initialize with an updated config in a cluster?

This may seem awkward, but with immutable infrastructure patterns of Kubernetes, a pod is not repaired or updated, but rather destroyed and recreated. I am not sure how to get ConfigMap to cascade so that StatefulSet will update the pods it manages. I am aware of a few ways to have alpha get the new updates:

1. Force an update with StatefulSet. One way to do this would be to add a new environment variable (or another setting), e.g. kubectl edit sts/<release>-dgraph-alpha. This will delete the pods and recreate them.
2. Delete single alpha pod, wait for StatefulSet to restore it, then repeat for each pod.
3. kubectl restart <resource> could work, but I have not personally tried this option yet.

Besides the ConfigMap, you can also add environment variables to the container spec in the StatefulSet, e.g. DGRAPH_ALPHA_WHITELIST. Doing this will cause the StatefulSet to roll out changes, and delete the alpha pods and install the new pods with the updated env vars.