kubernetes
/
website
mirror of https://github.com/kubernetes/website.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Merge pull request #27181 from neolit123/1.21-remove-self-hosting-page 

kubeadm: remove page about self-hosting support
pull/26723/head
Kubernetes Prow Robot 2021-03-23 18:50:05 -07:00 committed by GitHub
parent d0544c2f64 a198e2de6f
commit c6f0215796
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 0 additions and 68 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

68
content/en/docs/setup/production-environment/tools/kubeadm/self-hosting.md
View File

@ -1,68 +0,0 @@
---
reviewers:
- sig-cluster-lifecycle
title: Configuring your kubernetes cluster to self-host the control plane
content_type: concept
weight: 100
---
<!-- overview -->
### Self-hosting the Kubernetes control plane {#self-hosting}
kubeadm allows you to experimentally create a _self-hosted_ Kubernetes control
plane. This means that key components such as the API server, controller
manager, and scheduler run as [DaemonSet pods](/docs/concepts/workloads/controllers/daemonset/)
configured via the Kubernetes API instead of [static pods](/docs/tasks/configure-pod-container/static-pod/)
configured in the kubelet via static files.
To create a self-hosted cluster see the
[kubeadm alpha selfhosting pivot](/docs/reference/setup-tools/kubeadm/kubeadm-alpha/#cmd-selfhosting) command.
<!-- body -->
#### Caveats
{{< caution >}}
This feature pivots your cluster into an unsupported state, rendering kubeadm unable
to manage you cluster any longer. This includes `kubeadm upgrade`.
{{< /caution >}}
1. Self-hosting in 1.8 and later has some important limitations. In particular, a
self-hosted cluster _cannot recover from a reboot of the control-plane node_
without manual intervention.
1. By default, self-hosted control plane Pods rely on credentials loaded from
[`hostPath`](/docs/concepts/storage/volumes/#hostpath)
volumes. Except for initial creation, these credentials are not managed by
kubeadm.
1. The self-hosted portion of the control plane does not include etcd,
which still runs as a static Pod.
#### Process
The self-hosting bootstrap process is documented in the [kubeadm design
document](https://github.com/kubernetes/kubeadm/blob/master/docs/design/design_v1.9.md#optional-self-hosting).
In summary, `kubeadm alpha selfhosting` works as follows:
1. Waits for this bootstrap static control plane to be running and
healthy. This is identical to the `kubeadm init` process without self-hosting.
1. Uses the static control plane Pod manifests to construct a set of
DaemonSet manifests that will run the self-hosted control plane.
It also modifies these manifests where necessary, for example adding new volumes
for secrets.
1. Creates DaemonSets in the `kube-system` namespace and waits for the
resulting Pods to be running.
1. Once self-hosted Pods are operational, their associated static Pods are deleted
and kubeadm moves on to install the next component. This triggers kubelet to
stop those static Pods.
1. When the original static control plane stops, the new self-hosted control
plane is able to bind to listening ports and become active.