Mount hosts' /etc/hosts, /etc/resolv.conf, set host's hostname
when running the pod in the host's network.
Besides, do not set the DNS flags when running in host's network.
Automatic merge from submit-queue
Kubelet: Remove nsinit related code and bump up minimum docker apiversion
Docker has native exec support after 1.3.x. We never need this code now.
As for the apiversion, because Kubernetes supports 1.8.x - 1.10.x now, we should bump up the minimum docker apiversion.
@yujuhong I checked the [changes](https://github.com/docker/engine-api/blob/master/types/versions/v1p20/types.go), we are not relying on any of those changes. So #23506 should work with docker 1.8.x+
Add GeneratePodHostNameAndDomain() to RuntimeHelper to
get the hostname of the pod from kubelet.
Also update the logging flag to change the journal match from
_HOSTNAME to _MACHINE_ID.
This change removes RuntimeCache in the pod workers and the syncPod() function.
Note that it doesn't deprecate RuntimeCache completely as other components
still rely on the cache.
This address a TODO when collecting the node version information so it
will properly report the configured runtime and its version. Previously,
this was hardcoded to "docker://" and the docker version, and would show
"docker://1.9.1" even when the kubelet was configured to use rkt.
With this change, it will use the runtime's Type() and Version() data.
This also changes the container.Runtime interface to add an APIVersion()
method. This can be used when the runtime has separate versions for the
engine and the API, such as with Docker. The Docker minimum version
validation has been updated to use APIVersion(), and
DockerManager.Version() now returns the engine version.
This cache will be used to stores the PodStatus of all pods/containers
visible on the node. This will elimiate the need for pod workers to query the
container runtime directly.
Currently, pleg would report a event if a container transitions from running to
exited between relisting. However, if would not report any event if a container
gets stopped and removed between relisting. This event will eventually be
handled when the pod syncs periodically, but this is undesirable. This change
ensures that we detect all such events.
