Skip to content

Commit

Permalink
Adding user guides for federation replicasets and namespaces
Browse files Browse the repository at this point in the history
  • Loading branch information
nikhiljindal committed Sep 23, 2016
1 parent 11a93cf commit 1375b67
Show file tree
Hide file tree
Showing 3 changed files with 195 additions and 1 deletion.
4 changes: 3 additions & 1 deletion docs/user-guide/federation/index.md
Original file line number Diff line number Diff line change
Expand Up @@ -36,9 +36,11 @@ Once we have the control plane setup, we can start creating federation API
resources.
Following guides explain some of the resources in detail:

* [Services](/docs/user-guide/federation/federated-services/)
* [Events](/docs/user-guide/federation/events/)
* [Namespaces](/docs/user-guide/federation/namespaces/)
* [Replicasets](/docs/user-guide/federation/replicasets/)
* [Secrets](/docs/user-guide/federation/secrets/)
* [Services](/docs/user-guide/federation/federated-services/)
<!-- TODO: Add more guides here -->

[API reference docs](/federation/docs/api-reference/readme/) lists all the
Expand Down
105 changes: 105 additions & 0 deletions docs/user-guide/federation/replicasets.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,105 @@
---
---

This guide explains how to use replicasets in Federation control plane.


* TOC
{:toc}

## Prerequisites

This guide assumes that you have a running Kubernetes Cluster
Federation installation. If not, then head over to the
[federation admin guide](/docs/admin/federation/) to learn how to
bring up a cluster federation (or have your cluster administrator do
this for you). Other tutorials, for example
[this one](https://github.com/kelseyhightower/kubernetes-cluster-federation)
by Kelsey Hightower, are also available to help you.

You are also expected to have a basic
[working knowledge of Kubernetes](/docs/getting-started-guides/) in
general and [Replicasets](/docs/user-guide/replicasets/) in particular.

## Overview

Replicasets in federation control plane (referred to as "federated replicasets" in
this guide) are very similar to the traditional [Kubernetes
Replicasets](/docs/user-guide/replicasets/) providing the same functionality.
Creating them in the federation control plane ensures that the desired number of
replicas exist across the registered clusters.


## Creating a Federated Replicaset

The API for Federated Replicaset is 100% compatible with the
API for traditional Kubernetes Replicaset. You can create a replicaset by sending
a request to the federation apiserver.

You can do that using kubectl by running:

``` shell
kubectl --context=federation-cluster create -f myrs.yaml
```

The '--context=federation-cluster' flag tells kubectl to submit the
request to the Federation apiserver instead of sending it to a kubernetes
cluster.

Once a federated replicaset is created, the federation control plane will create
a replicaset in all underlying kubernetes clusters.
You can verify this by checking each of the underlying clusters, for example:

``` shell
kubectl --context=gce-asia-east1a get rs myrs
```

The above assumes that you have a context named 'gce-asia-east1a'
configured in your client for your cluster in that zone.

These replicasets in underlying clusters will match the federation replicaset
except in the number of replicas. Federation control plane will ensure that the
sum of replicas in each cluster match the desired number of replicas in the
federation replicaset.

### Spreading Replicas in Underlying Clusters

By default, replicas are spread equally in all the underlying clusters. For ex:
if you have 3 registered clusters and you create a federated replicaset with
`spec.replicas = 9`, then each replicaset in the 3 clusters will have
`spec.replicas=3`.
To modify the number of replicas in each cluster, you can specify
[FederatedReplicaSetPreference](https://github.com/kubernetes/kubernetes/blob/{{page.githubbranch}}/federation/apis/federation/types.go)
as annotation with key `federation.kubernetes.io/replica-set-preferences`
on federated replicaset.


## Updating a Federated Replicaset

You can update a federated replicaset as you would update a Kubernetes
replicaset, just send the request to federation apiserver instead of sending it
to a specific kubernetes cluster.
Federation control plan will ensure that whenever the federated replicaset is
updated, it updates the corresponding replicasets in all underlying clusters to
match it.
If your update includes a change in number of replicas then the federation
control plane will change the number of replicas in underlying clusters to
ensure that their sum remains equal to the number of desired replicas in
federated replicaset.

## Deleting a Federated Replicaset

You can delete a federated replicaset as you would delete a Kubernetes
replicaset, just send the request to federation apiserver instead of sending it
to a specific kubernetes cluster.

For example, you can do that using kubectl by running:

```shell
kubectl --context=federation-cluster delete rs myrs
```

Note that at this point, deleting a federated replicaset will not delete the
corresponding replicasets from underlying clusters.
Users are expected to delete them manually.
We intend to fix this in the future.
87 changes: 87 additions & 0 deletions docs/user-guide/federation/secrets.md
Original file line number Diff line number Diff line change
@@ -0,0 +1,87 @@
---
---

This guide explains how to use secrets in Federation control plane.


* TOC
{:toc}

## Prerequisites

This guide assumes that you have a running Kubernetes Cluster
Federation installation. If not, then head over to the
[federation admin guide](/docs/admin/federation/) to learn how to
bring up a cluster federation (or have your cluster administrator do
this for you). Other tutorials, for example
[this one](https://github.com/kelseyhightower/kubernetes-cluster-federation)
by Kelsey Hightower, are also available to help you.

You are also expected to have a basic
[working knowledge of Kubernetes](/docs/getting-started-guides/) in
general and [Secrets](/docs/user-guide/secrets/) in particular.

## Overview

Secrets in federation control plane (referred to as "federated secrets" in
this guide) are very similar to the traditional [Kubernetes
Secrets](/docs/user-guide/secrets/) providing the same functionality.
Creating them in the federation control plane ensures that they are synchronized
across all the clusters in federation.


## Creating a Federated Secret

The API for Federated Secret is 100% compatible with the
API for traditional Kubernetes Secret. You can create a secret by sending
a request to the federation apiserver.

You can do that using kubectl by running:

``` shell
kubectl --context=federation-cluster create -f mysecret.yaml
```

The '--context=federation-cluster' flag tells kubectl to submit the
request to the Federation apiserver instead of sending it to a kubernetes
cluster.

Once a federated secret is created, the federation control plane will create
a matching secret in all underlying kubernetes clusters.
You can verify this by checking each of the underlying clusters, for example:

``` shell
kubectl --context=gce-asia-east1a get rs myrs
```

The above assumes that you have a context named 'gce-asia-east1a'
configured in your client for your cluster in that zone.

These secrets in underlying clusters will match the federated secret.


## Updating a Federated Secret

You can update a federated secret as you would update a Kubernetes
secret, just send the request to federation apiserver instead of sending it
to a specific kubernetes cluster.
Federation control plan will ensure that whenever the federated secret is
updated, it updates the corresponding secrets in all underlying clusters to
match it.

## Deleting a Federated Secret

You can delete a federated secret as you would delete a Kubernetes
secret, just send the request to federation apiserver instead of sending it
to a specific kubernetes cluster.

For example, you can do that using kubectl by running:

```shell
kubectl --context=federation-cluster delete rs myrs
```

Note that at this point, deleting a federated secret will not delete the
corresponding secrets from underlying clusters.
Users are expected to delete them manually.
We intend to fix this in the future.

0 comments on commit 1375b67

Please sign in to comment.