Status: Open (View Workflow)
Environment:jenkins version 2.263.1
docker-workflow version 1.25
arch linux with kernel 5.4.86-1-lts (/proc/cmdline contains systemd.unified_cgroup_hierarchy=1 cgroup_no_v1=all)
cgroups v2 enabled
cgroups v1 disabled
With cgroups v2 running on the host there is a change to the behavior of the docker daemon regarding cgroups:
The default cgroup namespace mode (docker run --cgroupns) is "private" on v2, "host" on v1. (cf. https://github.com/docker/docker.github.io/blob/master/config/containers/runmetrics.md#running-docker-on-cgroup-v2).
Without any changes to the docker configuration the coding in src/main/java/org/jenkinsci/plugins/docker/workflow/client/ControlGroup.java of the docker-workflow-plugin fails, since /proc/self/cgroup does no longer contain the host-cgroup for the container.
A workaround is to set the option default-cgroupns-mode to "host" for the docker daemon.
Another way of detecting the containerization is needed.