kubeadm uses certificate rotation to replace the initial high-power
cert provided in --kubeconfig with a less powerful certificate on
the masters. This requires that we pass the contents of the client
config certData and keyData down into the cert store to populate
the initial client.
Add better comments to describe why the flow is required. Add a test
that verifies initial cert contents are written to disk. Change
the cert manager to not use MustRegister for prometheus so that
it can be tested.
Expose both a Stop() method (for cleanup) and a method to force
cert rotation, but only expose Stop() on the interface.
Verify that we choose the correct client.
Ensure that bootstrap+clientcert-rotation in the Kubelet can:
1. happen in the background so that static pods aren't blocked by bootstrap
2. collapse down to a single call path for requesting a CSR
3. reorganize the code to allow future flexibility in retrieving bootstrap creds
Fetching the first certificate and later certificates when the kubelet
is using client rotation and bootstrapping should share the same code
path. We also want to start the Kubelet static pod loop before
bootstrapping completes. Finally, we want to take an incremental step
towards improving how the bootstrap credentials are loaded from disk
(potentially allowing for a CLI call to get credentials, or a remote
plugin that better integrates with cloud providers or KSMs).
Reorganize how the kubelet client config is determined. If rotation is
off, simplify the code path. If rotation is on, load the config
from disk, and then pass that into the cert manager. The cert manager
creates a client each time it tries to request a new cert.
Preserve existing behavior where:
1. bootstrap kubeconfig is used if the current kubeconfig is invalid/expired
2. we create the kubeconfig file based on the bootstrap kubeconfig, pointing to
the location that new client certs will be placed
3. the newest client cert is used once it has been loaded
- 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
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.
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>.
refactor server.go to simplify the invokes to kubeFlags and KubeConfiguration
**What this PR does / why we need it**:
Since kubeFlags and KubeletConfiguration have been fields of KubeletServer, we just need to pass the reference of KubeletServer to the following functions. This will simplify the migrations of flags such as BootstrapCheckpointPath and others, as we don't have to specify from which object the migrated field comes.
**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**:
@mtaufen
**Release note**:
```release-note
NONE
```
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 65456, 65549). 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 flexvolume in containerized kubelets
Fixes flex volumes in containerized kubelets.
cc @jsafrane @chakri-nelluri @verult
Note to reviewers : e2e tests pass in local containarized cluster.
```release-note
Fix flexvolume in containarized kubelets
```
Automatic merge from submit-queue (batch tested with PRs 61330, 64793, 64675, 65059, 65368). 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 bug: kubelet potential panic
**What this PR does / why we need it**:
fix bug: kubelet may panic calling wg.Done after wg.Wait returned.
**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
```
Automatic merge from submit-queue (batch tested with PRs 63348, 63839, 63143, 64447, 64567). 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>.
Containerized subpath
**What this PR does / why we need it**:
Containerized kubelet needs a different implementation of `PrepareSafeSubpath` than kubelet running directly on the host.
On the host we safely open the subpath and then bind-mount `/proc/<pidof kubelet>/fd/<descriptor of opened subpath>`.
With kubelet running in a container, `/proc/xxx/fd/yy` on the host contains path that works only inside the container, i.e. `/rootfs/path/to/subpath` and thus any bind-mount on the host fails.
Solution:
- safely open the subpath and gets its device ID and inode number
- blindly bind-mount the subpath to `/var/lib/kubelet/pods/<uid>/volume-subpaths/<name of container>/<id of mount>`. This is potentially unsafe, because user can change the subpath source to a link to a bad place (say `/run/docker.sock`) just before the bind-mount.
- get device ID and inode number of the destination. Typical users can't modify this file, as it lies on /var/lib/kubelet on the host.
- compare these device IDs and inode numbers.
**Which issue(s) this PR fixes**
Fixes#61456
**Special notes for your reviewer**:
The PR contains some refactoring of `doBindSubPath` to extract the common code. New `doNsEnterBindSubPath` is added for the nsenter related parts.
**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.
Automatic merge from submit-queue (batch tested with PRs 63881, 64046, 63409, 63402, 63221). 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 responds to ConfigMap mutations for dynamic Kubelet config
This PR makes dynamic Kubelet config easier to reason about by leaving less room for silent skew scenarios. The new behavior is as follows:
- ConfigMap does not exist: Kubelet reports error status due to missing source
- ConfigMap is created: Kubelet starts using it
- ConfigMap is updated: Kubelet respects the update (but we discourage this pattern, in favor of incrementally migrating to a new ConfigMap)
- ConfigMap is deleted: Kubelet keeps using the config (non-disruptive), but reports error status due to missing source
- ConfigMap is recreated: Kubelet respects any updates (but, again, we discourage this pattern)
This PR also makes a small change to the config checkpoint file tree structure, because ResourceVersion is now taken into account when saving checkpoints. The new structure is as follows:
```
- dir named by --dynamic-config-dir (root for managing dynamic config)
| - meta
| - assigned (encoded kubeletconfig/v1beta1.SerializedNodeConfigSource object, indicating the assigned config)
| - last-known-good (encoded kubeletconfig/v1beta1.SerializedNodeConfigSource object, indicating the last-known-good config)
| - checkpoints
| - uid1 (dir for versions of object identified by uid1)
| - resourceVersion1 (dir for unpacked files from resourceVersion1)
| - ...
| - ...
```
fixes: #61643
```release-note
The dynamic Kubelet config feature will now update config in the event of a ConfigMap mutation, which reduces the chance for silent config skew. Only name, namespace, and kubeletConfigKey may now be set in Node.Spec.ConfigSource.ConfigMap. The least disruptive pattern for config management is still to create a new ConfigMap and incrementally roll out a new Node.Spec.ConfigSource.
```
This fixes an issue with KubeletConfiguration validation, where the
feature gates set by the new config were not taken into account.
Also fixes a validation issue with dynamic Kubelet config, where flag
precedence was not enforced prior to dynamic config validation in the
controller; this prevented rejection of dynamic configs that don't merge
well with values set via legacy flags.
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 to a structured status for dynamic kubelet config
This PR updates dynamic Kubelet config to use a structured status, rather than a node condition. This makes the status machine-readable, and thus more useful for config orchestration.
Fixes: #56896
```release-note
The status of dynamic Kubelet config is now reported via Node.Status.Config, rather than the KubeletConfigOk node condition.
```
Updates dynamic Kubelet config to use a structured status, rather than a
node condition. This makes the status machine-readable, and thus more
useful for config orchestration.
Fixes: #56896
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>.
check for commands in kubelet command line
**What this PR does / why we need it**:
Kubelet doesn't support subcommands and silently ignores them.
This causes a lot of confusion among users, for example:
Running 'kubelet logs' can produce this output:
```
I0206 16:20:40.010949 5712 feature_gate.go:220] feature gates: &{{} map[]}
I0206 16:20:40.011054 5712 controller.go:114] kubelet config controller: starting controller
...
error: failed to run Kubelet: failed to create kubelet:
misconfiguration: kubelet cgroup driver: "cgroupfs" is different from
docker cgroup driver: "systemd"
```
The output in this case looks like a valid log output. The error is not
caused by incorrectly configured cgroup driver though. It's caused by
the fact that kubelet ignores 'logs' subcommand, so 'kubelet logs' is
essentially the same as 'kubelet': it runs kubelet with the default set
of parameters, including default cgroup driver.
**The fix**:
Added check to prevent kubelet from running if user specifies
subcommands in the command line.
**Which issue(s) this PR fixes**:
Fixes: kubeadm issue 639
**Release note**:
```release-note
NONE
```
Andrew Kim