Automatic merge from submit-queue (batch tested with PRs 44606, 46038)
Fix serialization of EnforceNodeAllocatable
EnforceNodeAllocatable being `nil` and `[]` are treated in different
ways by kubelet. Namely, `nil` is replaced with `[]string{"pods"}` by
the defaulting mechanism.
E.g. if you run kubelet in Docker-in-Docker environment
you may need to run it with the following options:
`--cgroups-per-qos=false --enforce-node-allocatable=`
(this corresponds to EnforceNodeAllocatable being empty array and not
null) If you then grab kubelet configuration via /configz and try to
reuse it for dynamic kubelet config, kubelet will think that
EnforceNodeAllocatable is null, failing to run in the
Docker-in-Docker environment.
Encountered this while updating Virtlet for Kubernetes 1.6
(the dev environment is based on kubeadm-dind-cluster)
Automatic merge from submit-queue (batch tested with PRs 45953, 45889)
Add /metrics and profiling handlers to kube-proxy
Also expose "syncProxyRules latency" as a prometheus metrics.
Fix https://github.com/kubernetes/kubernetes/issues/45876
EnforceNodeAllocatable being `nil` and `[]` are treated in different
ways by kubelet. Namely, `nil` is replaced with `[]string{"pods"}` by
the defaulting mechanism.
E.g. if you run kubelet in Docker-in-Docker environment
you may need to run it with the following options:
`--cgroups-per-qos=false --enforce-node-allocatable=`
(this corresponds to EnforceNodeAllocatable being empty array and not
null) If you then grab kubelet configuration via /configz and try to
reuse it for dynamic kubelet config, kubelet will think that
EnforceNodeAllocatable is null, failing to run in the
Docker-in-Docker environment.
Encountered this while updating Virtlet for Kubernetes 1.6
(the dev environment is based on kubeadm-dind-cluster)
Automatic merge from submit-queue
Enable shared PID namespace by default for docker pods
**What this PR does / why we need it**: This PR enables PID namespace sharing for docker pods by default, bringing the behavior of docker in line with the other CRI runtimes when used with docker >= 1.13.1.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: ref #1615
**Special notes for your reviewer**: cc @dchen1107 @yujuhong
**Release note**:
```release-note
Kubernetes now shares a single PID namespace among all containers in a pod when running with docker >= 1.13.1. This means processes can now signal processes in other containers in a pod, but it also means that the `kubectl exec {pod} kill 1` pattern will cause the pod to be restarted rather than a single container.
```
The exported or public functions requires a doc comment to pass golint.
This commit has changes of conversion generated code. The actual doc
changes are added into a separate commit for a clean review.
Automatic merge from submit-queue
Add dockershim only mode
This PR added a `experimental-dockershim` hidden flag in kubelet to run dockershim only.
We introduce this flag mainly for cri validation test. In the future we should compile dockershim into another binary.
@yujuhong @feiskyer @xlgao-zju
/cc @kubernetes/sig-node-pr-reviews
Kubelet flags are not necessarily appropriate for the KubeletConfiguration
object. For example, this PR also removes HostnameOverride and NodeIP
from KubeletConfiguration. This is a preleminary step to enabling Nodes
to share configurations, as part of the dynamic Kubelet configuration
feature (#29459). Fields that must be unique for each node inhibit
sharing, because their values, by definition, cannot be shared.
Automatic merge from submit-queue
Allow multipe DNS servers as comma-seperated argument for kubelet --dns
This PR explores how kubectls "--dns" could be extended to specify multiple DNS servers for in-cluster PODs. Testing on the local libvirt-coreos cluster shows that multiple DNS server are injected without issues.
Specifying multiple DNS servers increases resilience against
- Packet drops
- Single server failure
I am debugging services that do 50+ DNS requests for a single incoming interactive request, thus highly increase the chance of a slowdown (+5s) due to a single packet drop. Switching to two DNS servers will reduce the impact of the issues (roughly +1s on glibc, 0s on musl, error-rate goes down to error-rate^2).
Note that there is no need to change any runtime related code as far as I know. In the case of "default" dns the /etc/resolv.conf is parsed and multiple DNS server are send to the backend anyway. This only adds the same capability for the clusterFirst case.
I've heard from @thockin that multiple DNS entries are somehow considered. I've no idea what was considered, though. This is what I would like to see for our production use, though.
```release-note
NONE
```
This change makes kubelet to use the CRI implementation by default,
unless the users opt out explicitly by using --enable-cri=false.
For the rkt integration, the --enable-cri flag will have no effect
since rktnetes does not use CRI.
Also, mark the original --experimental-cri flag hidden and deprecated,
so that we can remove it in the next release.
Depending on an exact cluster setup multiple dns may make sense.
Comma-seperated lists of DNS server are quite common as DNS servers
are always plain IPs.
Automatic merge from submit-queue (batch tested with PRs 39351, 39322)
Remove the deprecated --reconcile-cidr flag from kubelet
**What this PR does / why we need it**:
Removes the `--reconcile-cidr` flag that has been deprecated since v1.5
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
The `--reconcile-cidr` kubelet flag was removed since it had been deprecated since v1.5
```
@thockin
