set cgroupns=private

pkg/cluster/internal/providers/docker/provision.go

@@ -167,6 +167,11 @@ func commonArgs(cluster string, cfg *config.Cluster, networkName string, nodeNam
 		// this can be enabled by default in docker daemon.json, so we explicitly
 		// disable it, we want our entrypoint to be PID1, not docker-init / tini
 		"--init=false",
+		// note: requires API v1.41+ from Dec 2020 in Docker 20.10.0
+		// this is the default with cgroups v2 but not with cgroups v1, unless
+		// overridden in the daemon --default-cgroupns-mode
+		// https://github.com/docker/cli/pull/3699#issuecomment-1191675788
+		"--cgroupns=private",
 	}
 
 	// enable IPv6 if necessary

pkg/cluster/internal/providers/podman/provision.go

@@ -136,6 +136,8 @@ func commonArgs(cfg *config.Cluster, networkName string, nodeNames []string) ([]
 		"--label", fmt.Sprintf("%s=%s", clusterLabelKey, cfg.Name),
 		// specify container implementation to systemd
 		"-e", "container=podman",
+		// this is the default in cgroupsv2 but not in v1
+		"--cgroupns=private",
 	}
 
 	// enable IPv6 if necessary