configure file system in each node using kubernetes daemonset

Question

I was trying to increase core dump retention and node disk capacity using kubernetes deamonset. I can increase the retention period like this using a bash script but how do I do it using daemonset.

echo "/var/lib/systemd/coredump 0755 root root 10d" > /etc/tmpfiles.d/<filename>.conf.

In the same daemonset I want to increase the MaxUse field of file /etc/systemd/coredump.conf to 20%. Is it possible to do it in the same daemonset? I know this can be done using a cronjob but I don't want to use a cronjob. Hopefully the given information helps. Thanks for the help.

Answer 1

This is what I did to address this issue :

1. Create a config map which contains values for both retention period and MaxUse like this :

apiVersion: v1
kind: ConfigMap
metadata:
  name: core-cm
data:
  core.retention-period: Xd
  core.max-volume-use: XG

2. Pass these values in cm as an ENV variable inside the container of the daemonset and mount volume for the directories which needs to be changed

env:
  - name: RETENTION_PERIOD
    valueFrom:
      configMapKeyRef:
        name: core-cm
        key: core.retention-period
  - name: MAX_VOLUME_USE
    valueFrom:
      configMapKeyRef:
        name: core-cm
        key: core.max-volume-use

3. Write a script that will run inside the above mentioned container.

This configured all the nodes with the changes that I needed.