Unable to set kernel.core_pattern in K8s

Question

I am trying to modify the kernel.core_pattern but I am unable to modify it as it is Read-Only.

I have tried:

> echo 'kernel.core_pattern=/tmp/core-%e.%p.%h.%t' >> /etc/sysctl.conf

> Reload sysctl: sysctl --system

Applying /etc/sysctl.conf ... sysctl: setting key "kernel.core_pattern": Read-only file system cat /proc/sys/kernel/core_pattern 

I am no able to add it to the pod yaml either:

spec:
  securityContext:
    sysctls:
    - name: kernel.core_pattern
      value: "/tmp/core-%e.%p.%h.%t"

I keep getting this: SysctlForbidden

I created a PodSecurityPolicy as well:

apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
  name: sysctl-psp
spec:
  privileged: false  # Don't allow privileged pods!
  # The rest fills in some required fields.
  seLinux:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  runAsUser:
    rule: RunAsAny
  fsGroup:
    rule: RunAsAny
  allowedUnsafeSysctls:
  - kernel.*

Still no luck.

Any suggestions?

Answer 1

I was able to edit the kernel.core_pattern on the nodes in the cluster and that was reflected in the pods as well. But is a temporary work around as the core files generated are of zero size.