feature: configuration of pids_limit (podman)

rriemann commented 2 weeks ago

What Happened?

I use minikube in two ways:

minikube start --driver=podman --container-runtime=cri-o --cpus="4" --memory="4096"
minikube start --driver=podman --container-runtime=containerd --cpus="4" --memory="4096"

The workloads fail to create threads with error pthread_create failed (EAGAIN). I can fix this issue outside of minikube with:

podman run --pids-limit -1 alpine cat /sys/fs/cgroup/pids.max

However, I am missing a similar option for minikube to set --pids-limit.

Workaround to change the value system-wide

Have this in your /etc/containers/containers.conf:

[containers]
pids_limit=0

source: https://github.com/kubernetes-sigs/kind/issues/2896#issuecomment-1226184890

Attach the log file

I could not find anything on this in the minikube logs. However, dmesg has:

[ 5351.722836] cgroup: fork rejected by pids controller in /libpod_parent/libpod-6136e1615cd65448ba547e2db748f956cb90c27a7fd54665df8b320302debc07/kubepods.slice/kubepods-pode8d39171_af9d_4c07_b03e_6e72aefc26a8.slice/crio-27f14c6154e2630984fad3eb585e75456d10be978b80cb2c587efc77aa80f219.scope

Operating System

Redhat/Fedora

Driver

Podman

medyagh commented 2 weeks ago

@rriemann thanks for creating the issue, would you say it would be a good default to change the PID limit for everyone? or does this issue only affect your cluster with a specific workload ? do you mind sharing more about what your workload is ?

medyagh commented 2 weeks ago

/triage needs-information /kind support

rriemann commented 2 weeks ago

I am no expert in this area. I was playing with https://github.com/bitnami/charts/tree/main/bitnami/ejbca and just hit the limit on every deploy.

I assume that my OS Fedora limited pids for a reason and if I do not play with minikube, I'd like to conserve the default configuration of my OS.

I understand most people use minikube for testing. So in that sense I would recommend to inrease the default pid limit for everyone. I do not know which value would be a good fit. Hence, I believe the pid limit should be accessible via the arguments to the minikube start command and rest inside the user config next to the existing values for cpus and memory.

kubernetes / minikube