summaryrefslogtreecommitdiff
path: root/libpod/options.go
diff options
context:
space:
mode:
authorMatthew Heon <mheon@redhat.com>2020-05-08 17:41:50 -0400
committerMatthew Heon <mheon@redhat.com>2020-05-08 18:00:42 -0400
commitc57c560d9014b38040df8529f09208ba7743f794 (patch)
tree94a9db7cd4402b0778071ff3fc3daa0487dbc0b8 /libpod/options.go
parent7f8b31f5fb59d8b66a26dcd822863fbc18687905 (diff)
downloadpodman-c57c560d9014b38040df8529f09208ba7743f794.tar.gz
podman-c57c560d9014b38040df8529f09208ba7743f794.tar.bz2
podman-c57c560d9014b38040df8529f09208ba7743f794.zip
Fix bug where pods would unintentionally share cgroupns
This one was a massive pain to track down. The original symptom was an error message from rootless Podman trying to make a container in a pod. I unfortunately did not look at the error message closely enough to realize that the namespace in question was the cgroup namespace (the reproducer pod was explicitly set to only share the network namespace), else this would have been quite a bit shorter. I spent considerable effort trying to track down differences between the inspect output of the two containers, and when that failed I was forced to resort to diffing the OCI specs. That finally proved fruitful, and I was able to determine what should have been obvious all along: the container was joining the cgroup namespace of the infra container when it really ought not to have. From there, I discovered a variable collision in pod config. The UsePodCgroup variable means "create a parent cgroup for the pod and join containers in the pod to it". Unfortunately, it is very similar to UsePodUTS, UsePodNet, etc, which mean "the pod shares this namespace", so an accessor was accidentally added for it that indicated the pod shared the cgroup namespace when it really did not. Once I realized that, it was a quick fix - add a bool to the pod's configuration to indicate whether the cgroup ns was shared (distinct from UsePodCgroup) and use that for the accessor. Also included are fixes for `podman inspect` and `podman pod inspect` that fix them to actually display the state of the cgroup namespace (for container inspect) and what namespaces are shared (for pod inspect). Either of those would have made tracking this down considerably quicker. Fixes #6149 Signed-off-by: Matthew Heon <mheon@redhat.com>
Diffstat (limited to 'libpod/options.go')
-rw-r--r--libpod/options.go16
1 files changed, 16 insertions, 0 deletions
diff --git a/libpod/options.go b/libpod/options.go
index 33b423bce..05241baf3 100644
--- a/libpod/options.go
+++ b/libpod/options.go
@@ -1692,6 +1692,22 @@ func WithPodUTS() PodCreateOption {
}
}
+// WithPodCgroup tells containers in this pod to use the cgroup namespace
+// created for this pod.
+// Containers in a pod will inherit the kernel namespaces from the first
+// container added.
+func WithPodCgroup() PodCreateOption {
+ return func(pod *Pod) error {
+ if pod.valid {
+ return define.ErrPodFinalized
+ }
+
+ pod.config.UsePodCgroupNS = true
+
+ return nil
+ }
+}
+
// WithInfraContainer tells the pod to create a pause container
func WithInfraContainer() PodCreateOption {
return func(pod *Pod) error {