This patch makes the CRI `v1` API the new project-wide default version.
To allow backwards compatibility, a fallback to `v1alpha2` has been added
as well. This fallback can either used by automatically determined by
the kubelet.
Signed-off-by: Sascha Grunert <sgrunert@redhat.com>
As the final step, add the `dockerless` tags to all files in the
dockershim. Using `-tags=dockerless` in `go build`, we can compile
kubelet without the dockershim.
Once cadvisor no longer depends on `docker/docker`, compiling with
`-tags=dockerless` should be sufficient to compile the Kubelet w/o a
dependency on `docker/docker`.
Following changes in #87730, Kubelet is directly hcsshim to gather stats.
However, unlike `docker stats` API that was used before, hcsshim does not
keep information about exited containers.
When the Kubelet lists containers (`docker_container.go:ListContainers()`),
it sets `All: true`, retrieving non-running containers.
When docker stats is called with such container id, it'll return a valid JSON
with all values set to 0. The non-running containers are filtered later on in the process.
When the hcsshim is called with such container id, it'll return an error, effectively
stopping the stats retrieval for all containers.
This also incorporates the version string into the package name so
that incompatibile versions will fail to connect.
Arbitrary choices:
- The proto3 package name is runtime.v1alpha2. The proto compiler
normally translates this to a go package of "runtime_v1alpha2", but
I renamed it to "v1alpha2" for consistency with existing packages.
- kubelet/apis/cri is used as "internalapi". I left it alone and put the
public "runtimeapi" in kubelet/apis/cri/runtime.
We let dockershim implement the kubelet's internal (CRI) API as an
intermediary step before transitioning fully to communicate using gRPC.
Now that kubelet has been communicating to the runtime over gRPC for
multiple releases, we can safely retire the extra interface in
dockershim.
Implement CRI stats for dockershim using docker stats. This enables use
of the summary api to get container metrics on Windows where CRI stats
are enabled.
