ns.Close() will not remove and unmount the networking namespace
if it's not currently marked as mounted.
When we restore a sandbox, we generate the sandbox netns from
ns.GetNS() which does not mark the sandbox as mounted.
There currently is a PR open to fix that in the ns package:
https://github.com/containernetworking/cni/pull/342
but meanwhile this patch fixes a netns leak when restoring a pod.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In order to workaround a bug introduced with runc commit bc84f833,
we create a symbolic link to our permanent networking namespace so
that runC realizes that this is not the host namespace.
Although this bug is now fixed upstream (See commit f33de5ab4), this
patch works with pre rc3 runC versions.
We may want to revert that patch once runC 1.0.0 is released.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
With the networking namespace code added, we were reaching a
gocyclo complexitiy of 52. By moving the container creation and
starting code path out, we're back to reasonable levels.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In order for hypervisor based container runtimes to be able to
fully prepare their pod virtual machines networking interfaces,
this patch sets the pod networking namespace before creating the
sandbox container.
Once the sandbox networking namespace is prepared, the runtime
can scan the networking namespace interfaces and build the pod VM
matching interfaces (typically TAP interfaces) at pod sandbox
creation time. Not doing so means those runtimes would have to
rely on all hypervisors to support networking interfaces hotplug.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Because they need to prepare the hypervisor networking interfaces
and have them match the ones created in the pod networking
namespace (typically to bridge TAP and veth interfaces), hypervisor
based container runtimes need the sandbox pod networking namespace
to be set up before it's created. They can then prepare and start
the hypervisor interfaces when creating the pod virtual machine.
In order to do so, we need to create per pod persitent networking
namespaces that we pass to the CNI plugin. This patch leverages
the CNI ns package to create such namespaces under /var/run/netns,
and assign them to all pod containers.
The persitent namespace is removed when either the pod is stopped
or removed.
Since the StopPodSandbox() API can be called multiple times from
kubelet, we track the pod networking namespace state (closed or
not) so that we don't get a containernetworking/ns package error
when calling its Close() routine multiple times as well.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
And in particular make it not fail when removing an already removed
sandbox pod. According to the CRI spec:
[RemovePodSandbox] is idempotent, and must not return an error if
the sandbox has already been removed.
We now only print a warning instead of returning an error.
We still return an error when the passed pod ID is empty.
Fixes#240
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
