`kubectl get pod` already prints one container per line. This change fills in
the status for each container listed. This aims to help users quickly identify
unhealthy pods (e.g. in a crash loop) at a glance.
- The first row of every pod would display the pod information and status
- Each row of the subsequent rows corresponds to a container in that pod:
* STATUS refers to the container status (Running, Waiting, Terminated).
* CREATED refers to the elapsed time since the last start time of the
container.
* MESSAGE is a string which explains the last termination reason, and/or
the reason behind the waiting status.
Remove GetDockerServerVersion() from DockerContainerCommandRunner interface,
replaced with runtime.Version(). Also added Version type in runtime for version
comparision.
Kubelet kills unwanted pods in SyncPods, which directly impact the latency of a
sync iteration. This change parallelizes the cleanup to lessen the effect.
Eventually, we should leverage per-pod workers for cleanup, with the exception
of truly orphaned pods.
Currently, restart count are generated by examine dead docker containers, which
are subject to background garbage collection. Therefore, the restart count is
capped at 5 and can decrement if GC happens.
This change leverages the container statuses recorded in the pod status as a
reference point. If a container finished after the last observation, restart
count is incremented on top of the last observed count. If container is created
after last observation, but GC'd before the current observation time, kubelet
would not be aware of the existence of such a container, and would not increase
the restart count accordingly. However, the chance of this should be low, given
that pod statuses are reported frequently. Also, the restart cound would still
be increasing monotonically (with the exception of container insepct error).
Container creation/start failure cannot be reproduced by inspecting the
containers. This change caches such errors so that kubelet can retrieve it
later.
This change also extends FakeDockerClient to support setting error response
for a specific function.
We want to stop leaking more docker details into kubelet, and we also want to
consolidate some of the existing docker interfaces/structs. This change creates
DockerManager as the new home of some functions in dockertools/docker.go. It
also absorbs containerRunner. In addition, GetDockerPodStatus is renamed to
GetPodStatus with the entire pod passed to it so that it is simialr to the what
is defined in the container Runtime interface.
Eventually, DockerManager should implement the container Runtime interface, and
integrate DockerCache with a flag to turn on/off caching. Code in kubelet.go
should not be using docker client directly.
