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. 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>.
Move the` k8s.io/kubernetes/pkg/util/pointer` package to` k8s.io/utils/pointer`
**What this PR does / why we need it**:
Move `k8s.io/kubernetes/pkg/util/pointer` to `shared utils` directory, so that we can use it easily.
Close#66010 accidentally, and can't reopen it, so the same as #66010
**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 #
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
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.
The word 'manifest' technically refers to a container-group specification
that predated the Pod abstraction. We should avoid using this legacy
terminology where possible. Fortunately, the Kubelet's config API will
be beta in 1.10 for the first time, so we still had the chance to make
this change.
I left the flags alone, since they're deprecated anyway.
I changed a few var names in files I touched too, but this PR is the
just the first shot, not the whole campaign
(`git grep -i manifest | wc -l -> 1248`).
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>.
[Part 1] Remove docker dep in kubelet startup
**What this PR does / why we need it**:
Remove dependency of docker during kubelet start up.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*:
Part 1 of #54090
**Special notes for your reviewer**:
Changes include:
1. Move docker client initialization into dockershim pkg.
2. Pass a docker `ClientConfig` from kubelet to dockershim
3. Pass parameters needed by `FakeDockerClient` thru `ClientConfig` to dockershim
(TODO, the second part) Make dockershim tolerate when dockerd is down, otherwise it will still fail kubelet
Please note after this PR, kubelet will still fail if dockerd is down, this will be fixed in the subsequent PR by making dockershim tolerate dockerd failure (initializing docker client in a separate goroutine), and refactoring cgroup and log driver detection.
**Release note**:
```release-note
Remove docker dependency during kubelet start up
```
The pkg/api/testing can be removed whem kubeadm splits into
its own repository.
The pkg/kubemark probably will remain as is for the foreseeable
future.
Revert "Merge pull request #51857 from kubernetes/revert-51307-kc-type-refactor"
This reverts commit 9d27d92420, reversing
changes made to 2e69d4e625.
See original: #51307
We punted this from 1.8 so it could go through an API review. The point
of this PR is that we are trying to stabilize the kubeletconfig API so
that we can move it out of alpha, and unblock features like Dynamic
Kubelet Config, Kubelet loading its initial config from a file instead
of flags, kubeadm and other install tools having a versioned API to rely
on, etc.
We shouldn't rev the version without both removing all the deprecated
junk from the KubeletConfiguration struct, and without (at least
temporarily) removing all of the fields that have "Experimental" in
their names. It wouldn't make sense to lock in to deprecated fields.
"Experimental" fields can be audited on a 1-by-1 basis after this PR,
and if found to be stable (or sufficiently alpha-gated), can be restored
to the KubeletConfiguration without the "Experimental" prefix.
As we work towards providing a stable (v1) kubeletconfig API,
we cannot afford to have deprecated or "experimental" (alpha) fields
living in the KubeletConfiguration struct. This removes all existing
experimental or deprecated fields, and places them in KubeletFlags
instead.
I'm going to send another PR after this one that organizes the remaining
fields into substructures for readability. Then, we should try to move
to v1 ASAP.
It makes far more sense to focus on a clean API in kubeletconfig v2,
than to try and further clean up the existing "API" that everyone
already depends on.
This reverts commit f4afdecef8, reversing
changes made to e633a1604f.
This also fixes a bug where Kubemark was still using the core api scheme
to manipulate the Kubelet's types, which was the cause of the initial
revert.
Make adding nodes asynchronous. Add method for getting target
size of node group. Add method for getting node group for node.
Factor out some common code.
Automatic merge from submit-queue (batch tested with PRs 50016, 49583, 49930, 46254, 50337)
Alpha Dynamic Kubelet Configuration
Feature: https://github.com/kubernetes/features/issues/281
This proposal contains the alpha implementation of the Dynamic Kubelet Configuration feature proposed in ~#29459~ [community/contributors/design-proposals/dynamic-kubelet-configuration.md](https://github.com/kubernetes/community/blob/master/contributors/design-proposals/dynamic-kubelet-configuration.md).
Please note:
- ~The proposal doc is not yet up to date with this implementation, there are some subtle differences and some more significant ones. I will update the proposal doc to match by tomorrow afternoon.~
- ~This obviously needs more tests. I plan to write several O(soon). Since it's alpha and feature-gated, I'm decoupling this review from the review of the tests.~ I've beefed up the unit tests, though there is still plenty of testing to be done.
- ~I'm temporarily holding off on updating the generated docs, api specs, etc, for the sake of my reviewers 😄~ these files now live in a separate commit; the first commit is the one to review.
/cc @dchen1107 @vishh @bgrant0607 @thockin @derekwaynecarr
```release-note
Adds (alpha feature) the ability to dynamically configure Kubelets by enabling the DynamicKubeletConfig feature gate, posting a ConfigMap to the API server, and setting the spec.configSource field on Node objects. See the proposal at https://github.com/kubernetes/community/blob/master/contributors/design-proposals/dynamic-kubelet-configuration.md for details.
```
This is needed for cluster autoscaler e2e test to
run on kubemark. We need the ability to add and
remove nodes and operate on nodegroups. Kubemark
does not provide this at the moment.
Automatic merge from submit-queue (batch tested with PRs 48976, 49474, 40050, 49426, 49430)
Use presence of kubeconfig file to toggle standalone mode
Fixes#40049
```release-note
The deprecated --api-servers flag has been removed. Use --kubeconfig to provide API server connection information instead. The --require-kubeconfig flag is now deprecated. The default kubeconfig path is also deprecated. Both --require-kubeconfig and the default kubeconfig path will be removed in Kubernetes v1.10.0.
```
/cc @kubernetes/sig-cluster-lifecycle-misc @kubernetes/sig-node-misc
Automatic merge from submit-queue (batch tested with PRs 48976, 49474, 40050, 49426, 49430)
Remove duplicated import and wrong alias name of api package
**What this PR does / why we need it**:
**Which issue this PR fixes**: fixes#48975
**Special notes for your reviewer**:
/assign @caesarxuchao
**Release note**:
```release-note
NONE
```
Automatic merge from submit-queue
Remove flags low-diskspace-threshold-mb and outofdisk-transition-frequency
issue: #48843
This removes two flags replaced by the eviction manager. These have been depreciated for two releases, which I believe correctly follows the kubernetes depreciation guidelines.
```release-note
Remove depreciated flags: --low-diskspace-threshold-mb and --outofdisk-transition-frequency, which are replaced by --eviction-hard
```
cc @mtaufen since I am changing kubelet flags
cc @vishh @derekwaynecarr
/sig node
Replaces use of --api-servers with --kubeconfig in Kubelet args across
the turnup scripts. In many cases this involves generating a kubeconfig
file for the Kubelet and placing it in the correct location on the node.
Automatic merge from submit-queue (batch tested with PRs 48981, 47316, 49180)
Added golint check for pkg/kubelet.
**What this PR does / why we need it**:
Added golint check for pkg/kubelet, and make golint happy.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes#47315
**Release note**:
```release-note-none
```
Automatic merge from submit-queue (batch tested with PRs 47694, 47772, 47783, 47803, 47673)
Make different container runtimes constant
Make different container runtimes constant to avoid hardcode
**Release note**:
```release-note
NONE
```
Use shared informers instead of creating local controllers/reflectors
for the proxy's endpoints and service configs. This allows downstream
integrators to pass in preexisting shared informers to save on memory &
cpu usage.
This also enables the cache mutation detector for kube-proxy for those
presubmit jobs that already turn it on.
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
```
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.
