I havw a question, as part of the kubectl deployment process we currently run, we sometimes need to run migrations on the database as part of that process.
We do what we call a rollout restart after we have re-built a tagged Docker image.
However, we usually have anywhere between 2 and 4 pods, with randomly assigned names, e.g.:
web-7f54669b5f-c6z8m 1/1 Running 0 55s
web-7f54669b5f-fp2kw 1/1 Running 0 67sTo run, say, a database migration command, we could do:
kubectl exec --stdin --tty web-7f54669b5f-fp2kw -- python manage.py migrate --planThat's fine. But we were wondering if there a way to just target any of the "web" pods ...?
I'm assuming it's not possible, but not 100% sure why...
So, what you can do is add unique labels to all pods and fetch each one of them using labels.
Example:
kubectl exec --stdin --tty $(kubectl get po -l "<label_name>=<label_value>" \
-o jsonpath='{.items[0].metadata.name}') -- python manage.py migrate --plan