I was banging my head against the wall trying to figure out why my K8s configmap was ignoring my file permission settings and injecting a read-only version into the container. What was stranger was that it worked in my personal environment and not in the new one I set up for myself in the Windriver integration lab.
Well it turns out that there is a version difference between the 2 environments and this is exactly what the issue is. In the 1.8.9 version of K8s, a fix went in that ensures all configmaps, secrets,
My personal environment is running K8s 1.8.5 and the Windriver environment K8s 1.8.10
Here is the bug that led me to the discovery: https://github.com/coreos/bugs/issues/2384
The commit: https://github.com/kubernetes/kubernetes/issues/60814
And the changelog: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG-1.8.md#changelog-since-v188
This was the ticket I was working at the time and I know that SO has a similar problem where the container is trying to modify/move a file/directory that is injected via configmap.
OOM-900 - Getting issue details... STATUS
Here is the code. Note that setting the defaultMode: or mode: of a volume to something that is writeable isn't being honored anymore.
https://gerrit.onap.org/r/#/c/42325/