kubernetes - chown: changing ownership of '/data/db': Operation not permitted

Question

Can we use nfs volume plugin to maintain the High Availability and Disaster Recovery among the kubernetes cluster?

I am running the pod with MongoDB. Getting the error

chown: changing ownership of '/data/db': Operation not permitted .

Cloud any body, Please suggest me how to resolve the error? (or)

Is any alternative volume plugin is suggestible to achieve HA- DR in kubernetes cluster?

Answer 1

chown: changing ownership of '/data/db': Operation not permitted .

You'll want to either launch the mongo container as root, so that you can chown the directory, or if the image prohibits it (as some images already have a USER mongo clause that prohibits the container from escalating privileges back up to root), then one of two things: supersede the user with a securityContext stanza in containers: or use an initContainer: to preemptively change the target folder to be the mongo UID:

Approach #1:

containers:
- name: mongo
  image: mongo:something
  securityContext:
    runAsUser: 0

(which may require altering your cluster's config to permit such a thing to appear in a PodSpec)

Approach #2 (which is the one I use with Elasticsearch images):

initContainers:
- name: chmod-er
  image: busybox:latest
  command:
  - /bin/chown
  - -R
  - "1000"  # or whatever the mongo UID is, use string "1000" not 1000 due to yaml
  - /data/db
  volumeMounts:
  - name: mongo-data  # or whatever
    mountPath: /data/db
containers:
- name: mongo  # then run your container as before