Is there a way to load any kernel module ("modprobe nfsd" in my case) automatically after starting/upgrading nodes or in GKE? We are running an NFS server pod on our kubernetes cluster and it dies after every GKE upgrade
Tried both cos and ubuntu images, none of them seems to have nfsd loaded by default.
Also tried something like this, but it seems it does not do what it is supposed to do:
kind: DaemonSet
apiVersion: extensions/v1beta1
metadata:
name: nfsd-modprobe
labels:
app: nfsd-modprobe
spec:
template:
metadata:
labels:
app: nfsd-modprobe
spec:
hostPID: true
containers:
- name: nfsd-modprobe
image: gcr.io/google-containers/startup-script:v1
imagePullPolicy: Always
securityContext:
privileged: true
env:
- name: STARTUP_SCRIPT
value: |
#! /bin/bash
modprobe nfs
modprobe nfsd
while true; do sleep 1; doneBy default, you cannot load modules from inside a container because excluding kernel components is one of the main reason containers are lightweight and portable. You need to load the module from the host OS in order to make it available inside the container. This means you could simply launch a script that enables the kernel modules you want after each GKE upgrade.
However, there exists a somewhat hacky way to load kernel modules from inside a docker container. It all boils down to launching your container with escalated privileges and with access to certain host directories. You should try that if you really want to mount your kernel modules while inside a container.