Discussion is ongoing about how to best handle dual-stack with clouds
and autodetected IPs, but there is at least agreement that people on
bare metal ought to be able to specify two explicit IPs on dual-stack
hosts, so allow that.
When the dual-stack feature gate is enabled, set up dual-stack
iptables rules. (When it is not enabled, preserve the traditional
behavior of setting up IPv4 rules only, unless the user explicitly
passed an IPv6 --node-ip.)
DockerLegacyService interface is used throughout `pkg/kubelet`.
It used to live in the `pkg/kubelet/dockershim` package. While we
would eventually like to remove it entirely, we need to give users some form
of warning.
By including the interface in
`pkg/kubelet/legacy/logs.go`, we ensure the interface is
available to `pkg/kubelet`, even when we are building with the `dockerless`
tag (i.e. not compiling the dockershim).
While the interface always exists, there will be no implementations of the
interface when building with the `dockerless` tag. The lack of
implementations should not be an issue, as we only expect `pkg/kubelet` code
to need an implementation of the `DockerLegacyService` when we are using
docker. If we are using docker, but building with the `dockerless` tag, than
this will be just one of many things that breaks.
`pkg/kubelet/legacy` might not be the best name for the package... I'm
very open to finding a different package name or even an already
existing package.
We can remove all uses of `dockershim` from `cmd/kubelet`, by just
passing the docker options to the kubelet in their pure form, instead of
using them to create a `dockerClientConfig` (which is defined in
dockershim). We can then construct the `dockerClientConfig` only when we
actually need it.
Extract a `runDockershim` function into a file outside of `kubelet.go`.
We can use build tags to compile two separate functions... one which
actually runs dockershim and one that is a no-op.
As far as I can tell, nothing uses this type. As a result, it doesn't
really provide any benefit, and just clutters `kubelet.go`.
There's also the risk of it falling out of date with `NewMainKubelet`,
as nothing enforces `NewMainKubelet` being of the `Builder` type.
After a pod reaches a terminal state and all containers are complete
we can delete the pod from the API server. The dispatchWork method
needs to wait for all container status to be available before invoking
delete. Even after the worker stops, status updates will continue to
be delivered and the sync handler will continue to sync the pods, so
dispatchWork gets multiple opportunities to see status.
The previous code assumed that a pod in Failed or Succeeded had no
running containers, but eviction or deletion of running pods could
still have running containers whose status needed to be reported.
This modifies earlier test to guarantee that the "fallback" exit
code 137 is never reported to match the expectation that all pods
exit with valid status for all containers (unless some exceptional
failure like eviction were to occur while the test is running).
The kubelet must not allow a container that was reported failed in a
restartPolicy=Never pod to be reported to the apiserver as success.
If a client deletes a restartPolicy=Never pod, the dispatchWork and
status manager race to update the container status. When dispatchWork
(specifically podIsTerminated) returns true, it means all containers
are stopped, which means status in the container is accurate. However,
the TerminatePod method then clears this status. This results in a
pod that has been reported with status.phase=Failed getting reset to
status.phase.Succeeded, which is a violation of the guarantees around
terminal phase.
Ensure the Kubelet never reports that a container succeeded when it
hasn't run or been executed by guarding the terminate pod loop from
ever reporting 0 in the absence of container status.
GetAllocateResourcesPodAdmitHandler(). It is named as such to reflect its
new function. Also remove the Topology Manager feature gate check at higher level
kubelet.go, as it is now done in GetAllocateResourcesPodAdmitHandler().
As of https://github.com/kubernetes/kubernetes/pull/72831, the minimum
docker version is 1.13.1. (and the minimum API version is 1.26). The
only time the `RuntimeAdmitHandler` returns anything other than accept
is when the Docker API version < 1.24. In other words, we can be
confident that Docker will always support sysctl.
As a result, we can delete this unnecessary and docker-specific code.
This diff contains a strict refactor; there are no behavioral changes.
Address a long standing TODO in `oom_watcher_linux_test.go` around test
coverage. We refactor our `oom.Watcher` so it takes in a struct
fulfulling the `streamer` interface (i.e. defines `StreamOoms` method).
In production, we will continue to use the `oomparser` from `cadvisor`.
However, for testing purposes, we can now create our own `fakeStreamer`,
and control how it streams `oomparser.OomInstance`. With this fake, we
can implement richer unit testing for the `oom.Watcher` itself.
Actually adding the additional unit tests will come in a later commit.
This patch removes pkg/util/mount completely, and replaces it with the
mount package now located at k8s.io/utils/mount. The code found at
k8s.io/utils/mount was moved there from pkg/util/mount, so the code is
identical, just no longer in-tree to k/k.
Kubelet and kube-proxy both had loops to ensure that their iptables
rules didn't get deleted, by repeatedly recreating them. But on
systems with lots of iptables rules (ie, thousands of services), this
can be very slow (and thus might end up holding the iptables lock for
several seconds, blocking other operations, etc).
The specific threat that they need to worry about is
firewall-management commands that flush *all* dynamic iptables rules.
So add a new iptables.Monitor() function that handles this by creating
iptables-flush canaries and only triggering a full rule reload after
noticing that someone has deleted those chains.
The firewalld monitoring code was not well tested (and not easily
testable), would never be triggered on most platforms, and was only
being taken advantage of from one place (kube-proxy), which didn't
need it anyway since it already has its own resync loop.
Since the firewalld monitoring was the only consumer of pkg/util/dbus,
we can also now delete that.
This patch moves the HostUtil functionality from the util/mount package
to the volume/util/hostutil package.
All `*NewHostUtil*` calls are changed to return concrete types instead
of interfaces.
All callers are changed to use the `*NewHostUtil*` methods instead of
directly instantiating the concrete types.
DesiredStateOfWorldPopulator should skip a volume that is not used in any
pod. "Used" means either mounted (via volumeMounts) or used as raw block
device (via volumeDevices).
Especially when block feature is disabled, a block volume must not get into
DesiredStateOfWorld, because it would be formatted and mounted there.
libcni 0.7.0 caches ADD operation results and allows the runtime to
retrieve these from the cache. In case the user wants a different
cache directory than the defaul, plumb that through like we do
for --cni-bin-dir and --cni-conf-dir.
This patch refactors pkg/util/mount to be more usable outside of
Kubernetes. This is done by refactoring mount.Interface to only contain
methods that are not K8s specific. Methods that are not relevant to
basic mount activities but still have OS-specific implementations are
now found in a mount.HostUtils interface.
Previously, the code base had both `housekeeping` and `houseKeeping`,
which made case sensitive search in vim difficult. Standardize on
`housekeeping`, which was by far the most popular.
This is the 2nd PR to move CSINodeInfo/CSIDriver APIs to
v1beta1 core storage APIs. It includes controller side changes.
It depends on the PR with API changes:
https://github.com/kubernetes/kubernetes/pull/73883
Modify kubelet plugin watcher to support older CSI drivers that use an
the old plugins directory for socket registration.
Also modify CSI plugin registration to support multiple versions of CSI
registering with the same name.
- Move from the old github.com/golang/glog to k8s.io/klog
- klog as explicit InitFlags() so we add them as necessary
- we update the other repositories that we vendor that made a similar
change from glog to klog
* github.com/kubernetes/repo-infra
* k8s.io/gengo/
* k8s.io/kube-openapi/
* github.com/google/cadvisor
- Entirely remove all references to glog
- Fix some tests by explicit InitFlags in their init() methods
Change-Id: I92db545ff36fcec83afe98f550c9e630098b3135
When node lease feature is enabled, kubelet reports node status to api server
only if there is some change or it didn't report over last report interval.
Individual implementations are not yet being moved.
Fixed all dependencies which call the interface.
Fixed golint exceptions to reflect the move.
Added project info as per @dims and
https://github.com/kubernetes/kubernetes-template-project.
Added dims to the security contacts.
Fixed minor issues.
Added missing template files.
Copied ControllerClientBuilder interface to cp.
This allows us to break the only dependency on K8s/K8s.
Added TODO to ControllerClientBuilder.
Fixed GoDeps.
Factored in feedback from JustinSB.
Automatic merge from submit-queue (batch tested with PRs 65251, 67255, 67224, 67297, 68105). If you want to cherry-pick this change to another branch, please follow the instructions here: https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md.
Promote mount propagation to GA
**What this PR does / why we need it**:
This PR promotes mount propagation to GA.
Website PR: https://github.com/kubernetes/website/pull/9823
**Release note**:
```release-note
Mount propagation has promoted to GA. The `MountPropagation` feature gate is deprecated and will be removed in 1.13.
```
Automatic merge from submit-queue (batch tested with PRs 64283, 67910, 67803, 68100). If you want to cherry-pick this change to another branch, please follow the instructions here: https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md.
CSI Cluster Registry and Node Info CRDs
**What this PR does / why we need it**:
Introduces the new `CSIDriver` and `CSINodeInfo` API Object as proposed in https://github.com/kubernetes/community/pull/2514 and https://github.com/kubernetes/community/pull/2034
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes https://github.com/kubernetes/features/issues/594
**Special notes for your reviewer**:
Per the discussion in https://groups.google.com/d/msg/kubernetes-sig-storage-wg-csi/x5CchIP9qiI/D_TyOrn2CwAJ the API is being added to the staging directory of the `kubernetes/kubernetes` repo because the consumers will be attach/detach controller and possibly kubelet, but it will be installed as a CRD (because we want to move in the direction where the API server is Kubernetes agnostic, and all Kubernetes specific types are installed).
**Release note**:
```release-note
Introduce CSI Cluster Registration mechanism to ease CSI plugin discovery and allow CSI drivers to customize Kubernetes' interaction with them.
```
CC @jsafrane
Automatic merge from submit-queue (batch tested with PRs 64283, 67910, 67803, 68100). If you want to cherry-pick this change to another branch, please follow the instructions here: https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md.
Add a ProcMount option to the SecurityContext & AllowedProcMountTypes to PodSecurityPolicy
So there is a bit of a chicken and egg problem here in that the CRI runtimes will need to implement this for there to be any sort of e2e testing.
**What this PR does / why we need it**: This PR implements design proposal https://github.com/kubernetes/community/pull/1934. This adds a ProcMount option to the SecurityContext and AllowedProcMountTypes to PodSecurityPolicy
Relies on https://github.com/google/cadvisor/pull/1967
**Release note**:
```release-note
ProcMount added to SecurityContext and AllowedProcMounts added to PodSecurityPolicy to allow paths in the container's /proc to not be masked.
```
cc @Random-Liu @mrunalp
Automatic merge from submit-queue (batch tested with PRs 67739, 65222). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Honor --hostname-override, report compatible hostname addresses with cloud provider
xref #677147828e5d made cloud providers authoritative for the addresses reported on Node objects, so that the addresses used by the node (and requested as SANs in serving certs) could be verified via cloud provider metadata.
This had the effect of no longer reporting addresses of type Hostname for Node objects for some cloud providers. Cloud providers that have the instance hostname available in metadata should add a `type: Hostname` address to node status. This is being tracked in #67714
This PR does a couple other things to ease the transition to authoritative cloud providers:
* if `--hostname-override` is set on the kubelet, make the kubelet report that `Hostname` address. if it can't be verified via cloud-provider metadata (for cert approval, etc), the kubelet deployer is responsible for fixing the situation by adjusting the kubelet configuration (as they were in 1.11 and previously)
* if `--hostname-override` is not set, *and* the cloud provider didn't report a Hostname address, *and* the auto-detected hostname matches one of the addresses the cloud provider *did* report, make the kubelet report that as a Hostname address. That lets the addresses remain verifiable via cloud provider metadata, while still including a `Hostname` address whenever possible.
/sig node
/sig cloud-provider
/cc @mikedanese
fyi @hh
```release-note
NONE
```
This extends the Kubelet to create and periodically update leases in a
new kube-node-lease namespace. Based on [KEP-0009](https://github.com/kubernetes/community/blob/master/keps/sig-node/0009-node-heartbeat.md),
these leases can be used as a node health signal, and will allow us to
reduce the load caused by over-frequent node status reporting.
- add NodeLease feature gate
- add kube-node-lease system namespace for node leases
- add Kubelet option for lease duration
- add Kubelet-internal lease controller to create and update lease
- add e2e test for NodeLease feature
- modify node authorizer and node restriction admission controller
to allow Kubelets access to corresponding leases
Automatic merge from submit-queue (batch tested with PRs 65247, 63633, 67425). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
fix kubelet iptclient in ipv6 cluster
**What this PR does / why we need it**:
Kubelet uses "iptables" instead of "ip6tables" in an ipv6-only cluster. This causes failed traffic for type: LoadBalancer services (and probably a lot of other problems).
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes#67398
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue (batch tested with PRs 66177, 66185, 67136, 67157, 65065). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
kubelet: reduce logging for backoff situations
xref https://bugzilla.redhat.com/show_bug.cgi?id=1555057#c6
Pods that are in `ImagePullBackOff` or `CrashLoopBackOff` currently generate a lot of logging at the `glog.Info()` level. This PR moves some of that logging to `V(3)` and avoids logging in situations where the `SyncPod` only fails because pod are in a BackOff error condition.
@derekwaynecarr @liggitt
Automatic merge from submit-queue (batch tested with PRs 67177, 53042). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Adding unit tests to methods of pod's format
What this PR does / why we need it:
Add unit test cases, thank you!
Automatic merge from submit-queue (batch tested with PRs 58755, 66414). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Use probe based plugin watcher mechanism in Device Manager
**What this PR does / why we need it**:
Uses this probe based utility in the device plugin manager.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes#56944
**Notes For Reviewers**:
Changes are backward compatible and existing device plugins will continue to work. At the same time, any new plugins that has required support for probing model (Identity service implementation), will also work.
**Release note**
```release-note
Add support kubelet plugin watcher in device manager.
```
/sig node
/area hw-accelerators
/cc /cc @jiayingz @RenaudWasTaken @vishh @ScorpioCPH @sjenning @derekwaynecarr @jeremyeder @lichuqiang @tengqm @saad-ali @chakri-nelluri @ConnorDoyle
The --docker-disable-shared-pid flag has been deprecated since 1.10 and
has been superceded by ShareProcessNamespace in the pod API, which is
scheduled for beta in 1.12.
Automatic merge from submit-queue (batch tested with PRs 66152, 66406, 66218, 66278, 65660). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Refactor kubelet node status setters, add test coverage
This internal refactor moves the node status setters to a new package, explicitly injects dependencies to facilitate unit testing, and adds individual unit tests for the setters.
I gave each setter a distinct commit to facilitate review.
Non-goals:
- I intentionally excluded the class of setters that return a "modified" boolean, as I want to think more carefully about how to cleanly handle the behavior, and this PR is already rather large.
- I would like to clean up the status update control loops as well, but that belongs in a separate PR.
```release-note
NONE
```
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Derive kubelet serving certificate CSR template from node status addresses
xref https://github.com/kubernetes/features/issues/267fixes#55633
Builds on https://github.com/kubernetes/kubernetes/pull/65587
* Makes the cloud provider authoritative when recording node status addresses
* Makes the node status addresses authoritative for the kube-apiserver determining how to speak to a kubelet (stops paying attention to the hostname label when determining how to reach a kubelet, which was only done to support kubelets < 1.5)
* Updates kubelet certificate rotation to be driven from node status
* Avoids needing to compute node addresses a second time, and differently, in order to request serving certificates.
* Allows the kubelet to react to changes in its status addresses by updating its serving certificate
* Allows the kubelet to be driven by external cloud providers recording node addresses on the node status
test procedure:
```sh
# setup
export FEATURE_GATES=RotateKubeletServerCertificate=true
export KUBELET_FLAGS="--rotate-server-certificates=true --cloud-provider=external"
# cleanup from previous runs
sudo rm -fr /var/lib/kubelet/pki/
# startup
hack/local-up-cluster.sh
# wait for a node to register, verify it didn't set addresses
kubectl get nodes
kubectl get node/127.0.0.1 -o jsonpath={.status.addresses}
# verify the kubelet server isn't available, and that it didn't populate a serving certificate
curl --cacert _output/certs/server-ca.crt -v https://localhost:10250/pods
ls -la /var/lib/kubelet/pki
# set an address on the node
curl -X PATCH http://localhost:8080/api/v1/nodes/127.0.0.1/status \
-H "Content-Type: application/merge-patch+json" \
--data '{"status":{"addresses":[{"type":"Hostname","address":"localhost"}]}}'
# verify a csr was submitted with the right SAN, and approve it
kubectl describe csr
kubectl certificate approve csr-...
# verify the kubelet connection uses a cert that is properly signed and valid for the specified hostname, but NOT the IP
curl --cacert _output/certs/server-ca.crt -v https://localhost:10250/pods
curl --cacert _output/certs/server-ca.crt -v https://127.0.0.1:10250/pods
ls -la /var/lib/kubelet/pki
# set an hostname and IP address on the node
curl -X PATCH http://localhost:8080/api/v1/nodes/127.0.0.1/status \
-H "Content-Type: application/merge-patch+json" \
--data '{"status":{"addresses":[{"type":"Hostname","address":"localhost"},{"type":"InternalIP","address":"127.0.0.1"}]}}'
# verify a csr was submitted with the right SAN, and approve it
kubectl describe csr
kubectl certificate approve csr-...
# verify the kubelet connection uses a cert that is properly signed and valid for the specified hostname AND IP
curl --cacert _output/certs/server-ca.crt -v https://localhost:10250/pods
curl --cacert _output/certs/server-ca.crt -v https://127.0.0.1:10250/pods
ls -la /var/lib/kubelet/pki
```
```release-note
* kubelets that specify `--cloud-provider` now only report addresses in Node status as determined by the cloud provider
* kubelet serving certificate rotation now reacts to changes in reported node addresses, and will request certificates for addresses set by an external cloud provider
```
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Store the latest cloud provider node addresses
**What this PR does / why we need it**:
Buffer the recently retrieved node address so they can be used as soon as the next node status update is run.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes#65814
**Special notes for your reviewer**:
**Release note**:
```release-note
None
```
Automatic merge from submit-queue (batch tested with PRs 65290, 65326, 65289, 65334, 64860). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
checkLimitsForResolvConf for the pod create and update events instead of checking period
**What this PR does / why we need it**:
- Check for the same at pod create and update events instead of checking continuously for every 30 seconds.
- Increase the logging level to 4 or higher since the event is not catastrophic to cluster health .
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes#64849
**Special notes for your reviewer**:
@ravisantoshgudimetla
**Release note**:
```release-note
checkLimitsForResolvConf for the pod create and update events instead of checking period
```
Automatic merge from submit-queue (batch tested with PRs 65187, 65206, 65223, 64752, 65238). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Kubelet watches necessary secrets/configmaps instead of periodic polling
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move oldNodeUnschedulable pkg var to kubelet struct
**What this PR does / why we need it**:
move oldNodeUnschedulable pkg var to kubelet struct
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Add proxy for container streaming in kubelet for streaming auth.
For https://github.com/kubernetes/kubernetes/issues/36666, option 2 of https://github.com/kubernetes/kubernetes/issues/36666#issuecomment-378440458.
This PR:
1. Removed the `DirectStreamingRuntime`, and changed `IndirectStreamingRuntime` to `StreamingRuntime`. All `DirectStreamingRuntime`s, `dockertools` and `rkt`, were removed.
2. Proxy container streaming in kubelet instead of returning redirect to apiserver. This solves the container runtime authentication issue, which is what we agreed on in https://github.com/kubernetes/kubernetes/issues/36666.
Please note that, this PR replaced the redirect with proxy directly instead of adding a knob to switch between the 2 behaviors. For existing CRI runtimes like containerd and cri-o, they should change to serve container streaming on localhost, so as to make the whole container streaming connection secure.
If a general authentication mechanism proposed in https://github.com/kubernetes/kubernetes/issues/62747 is ready, we can switch back to redirect, and all code can be found in github history.
Please also note that this added some overhead in kubelet when there are container streaming connections. However, the actual bottleneck is in the apiserver anyway, because it does proxy for all container streaming happens in the cluster. So it seems fine to get security and simplicity with this overhead. @derekwaynecarr @mrunalp Are you ok with this? Or do you prefer a knob?
@yujuhong @timstclair @dchen1107 @mikebrow @feiskyer
/cc @kubernetes/sig-node-pr-reviews
**Release note**:
```release-note
Kubelet now proxies container streaming between apiserver and container runtime. The connection between kubelet and apiserver is authenticated. Container runtime should change streaming server to serve on localhost, to make the connection between kubelet and container runtime local.
In this way, the whole container streaming connection is secure. To switch back to the old behavior, set `--redirect-container-streaming=true` flag.
```
While I normally try to avoid adding flags, this is a short term
scalability fix for v1.11, and there are other long-term solutions in
the works, so we shouldn't commit to this in the v1beta1 Kubelet config.
Flags are our escape hatch.
The goal of this change is to remove the registration of signal
handling from pkg/kubelet. We now pass in a stop channel.
If you register a signal handler in `main()` to aid in a controlled
and deliberate exit then the handler registered in `pkg/kubelet` often
wins and the process exits immediately. This means all other signal
handler registrations are currently racy if `DockerServer.Start()` is
directly or indirectly invoked.
This change also removes another signal handler registration from
`NewAPIServerCommand()`; a stop channel is now passed to this
function.
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Add memcg notifications for allocatable cgroup
**What this PR does / why we need it**:
Use memory cgroup notifications to trigger the eviction manager when the allocatable eviction threshold is crossed. This allows the eviction manager to respond more quickly when the allocatable cgroup's available memory becomes low. Evictions are preferable to OOMs in the cgroup since the kubelet can enforce its priorities on which pod is killed.
**Which issue(s) this PR fixes**:
Fixes https://github.com/kubernetes/kubernetes/issues/57901
**Special notes for your reviewer**:
This adds the alloctable cgroup from the container manager to the eviction config.
**Release note**:
```release-note
NONE
```
/sig node
/priority important-soon
/kind feature
I would like this to be included in the 1.11 release.
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track/close kubelet->API connections on heartbeat failure
xref #48638
xref https://github.com/kubernetes-incubator/kube-aws/issues/598
we're already typically tracking kubelet -> API connections and have the ability to force close them as part of client cert rotation. if we do that tracking unconditionally, we gain the ability to also force close connections on heartbeat failure as well. it's a big hammer (means reestablishing pod watches, etc), but so is having all your pods evicted because you didn't heartbeat.
this intentionally does minimal refactoring/extraction of the cert connection tracking transport in case we want to backport this
* first commit unconditionally sets up the connection-tracking dialer, and moves all the cert management logic inside an if-block that gets skipped if no certificate manager is provided (view with whitespace ignored to see what actually changed)
* second commit plumbs the connection-closing function to the heartbeat loop and calls it on repeated failures
follow-ups:
* consider backporting this to 1.10, 1.9, 1.8
* refactor the connection managing dialer to not be so tightly bound to the client certificate management
/sig node
/sig api-machinery
```release-note
kubelet: fix hangs in updating Node status after network interruptions/changes between the kubelet and API server
```
Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Report node DNS info with --node-ip
**What this PR does / why we need it**:
This PR adds `ExternalDNS`, `InternalDNS`, and `ExternalIP` info for kubelets with the `--nodeip` flag enabled.
**Which issue(s) this PR fixes**
Fixes#63158
**Special notes for your reviewer**:
I added a field to the Kubelet to make IP validation more testable (`validateNodeIP` relies on the `net` package and the IP address of the host that is executing the test.) I also converted the test to use a table so new cases could be added more easily.
**Release Notes**
```release-note
Report node DNS info with --node-ip flag
```
@andrewsykim
@nckturner
/sig node
/sig network
