Moving etcd topic to Concepts.

pull/3393/head^2
ihutchin 2017-03-17 15:16:40 -05:00 committed by Andrew Chen
parent 956578f6df
commit dee3def6c1
3 changed files with 53 additions and 42 deletions

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@ -75,6 +75,10 @@ toc:
- docs/concepts/storage/volumes.md - docs/concepts/storage/volumes.md
- docs/concepts/storage/persistent-volumes.md - docs/concepts/storage/persistent-volumes.md
- title: Storage
section:
- docs/concepts/storage/etcd-store-api-object.md
- title: Services, Load Balancing, and Networking - title: Services, Load Balancing, and Networking
section: section:
- docs/concepts/services-networking/service.md - docs/concepts/services-networking/service.md

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@ -4,46 +4,6 @@ assignees:
title: Configuring Kubernetes Use of etcd title: Configuring Kubernetes Use of etcd
--- ---
[etcd](https://coreos.com/etcd/docs/latest/) is a highly-available key value {% include user-guide-content-moved.md %}
store which Kubernetes uses for persistent storage of all of its REST API
objects.
## Configuration: high-level goals [Configuring Kubernetes Use of etcd](/docs/concepts/storage/etcd-store-api-object/)
Access Control: give *only* kube-apiserver read/write access to etcd. You do not
want apiserver's etcd exposed to every node in your cluster (or worse, to the
internet at large), because access to etcd is equivalent to root in your
cluster.
Data Reliability: for reasonable safety, either etcd needs to be run as a
[cluster](/docs/admin/high-availability/#clustering-etcd) (multiple machines each running
etcd) or etcd's data directory should be located on durable storage (e.g., GCE's
persistent disk). In either case, if high availability is required--as it might
be in a production cluster--the data directory ought to be [backed up
periodically](https://coreos.com/etcd/docs/latest/op-guide/recovery.html),
to reduce downtime in case of corruption.
## Default configuration
The default setup scripts use kubelet's file-based static pods feature to run etcd in a
[pod](http://releases.k8s.io/{{page.githubbranch}}/cluster/saltbase/salt/etcd/etcd.manifest). This manifest should only
be run on master VMs. The default location that kubelet scans for manifests is
`/etc/kubernetes/manifests/`.
## Kubernetes's usage of etcd
By default, Kubernetes objects are stored under the `/registry` key in etcd.
This path can be prefixed by using the [kube-apiserver](/docs/admin/kube-apiserver) flag
`--etcd-prefix="/foo"`.
`etcd` is the only place that Kubernetes keeps state.
## Troubleshooting
To test whether `etcd` is running correctly, you can try writing a value to a
test key. On your master VM (or somewhere with firewalls configured such that
you can talk to your cluster's etcd), try:
```shell
curl -fs -X PUT "http://${host}:${port}/v2/keys/_test"
```

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@ -0,0 +1,47 @@
---
title: Configuring Kubernetes Use of etcd
---
[etcd](https://coreos.com/etcd/docs/latest/) is a highly-available key value
store which Kubernetes uses for persistent storage of all of its REST API
objects.
## Configuration: high-level goals
Access Control: give *only* kube-apiserver read/write access to etcd. You do not
want apiserver's etcd exposed to every node in your cluster (or worse, to the
internet at large), because access to etcd is equivalent to root in your
cluster.
Data Reliability: for reasonable safety, either etcd needs to be run as a
[cluster](/docs/admin/high-availability/#clustering-etcd) (multiple machines each running
etcd) or etcd's data directory should be located on durable storage (e.g., GCE's
persistent disk). In either case, if high availability is required--as it might
be in a production cluster--the data directory ought to be [backed up
periodically](https://coreos.com/etcd/docs/latest/op-guide/recovery.html),
to reduce downtime in case of corruption.
## Default configuration
The default setup scripts use kubelet's file-based static pods feature to run etcd in a
[pod](http://releases.k8s.io/{{page.githubbranch}}/cluster/saltbase/salt/etcd/etcd.manifest). This manifest should only
be run on master VMs. The default location that kubelet scans for manifests is
`/etc/kubernetes/manifests/`.
## Kubernetes's usage of etcd
By default, Kubernetes objects are stored under the `/registry` key in etcd.
This path can be prefixed by using the [kube-apiserver](/docs/admin/kube-apiserver) flag
`--etcd-prefix="/foo"`.
`etcd` is the only place that Kubernetes keeps state.
## Troubleshooting
To test whether `etcd` is running correctly, you can try writing a value to a
test key. On your master VM (or somewhere with firewalls configured such that
you can talk to your cluster's etcd), try:
```shell
curl -fs -X PUT "http://${host}:${port}/v2/keys/_test"
```