From b4ffa837a59642d80c50a2cbbcc010a9bd4239d8 Mon Sep 17 00:00:00 2001 From: "Madhusudan.C.S" Date: Mon, 20 Mar 2017 13:29:59 -0700 Subject: [PATCH] Address review comments. --- .../set-up-cluster-federation-kubefed.md | 99 ++++++++++++++----- 1 file changed, 74 insertions(+), 25 deletions(-) diff --git a/docs/tutorials/federation/set-up-cluster-federation-kubefed.md b/docs/tutorials/federation/set-up-cluster-federation-kubefed.md index ae246bbac0..f0f97dcfcd 100644 --- a/docs/tutorials/federation/set-up-cluster-federation-kubefed.md +++ b/docs/tutorials/federation/set-up-cluster-federation-kubefed.md @@ -16,7 +16,7 @@ existing federation control plane. This guide explains how to administer a Kubernetes Cluster Federation using `kubefed`. -> Note: `kubefed` is in beta as of Kubernetes 1.6. +> Note: `kubefed` is a beta feature in Kubernetes 1.6. ## Prerequisites @@ -27,21 +27,37 @@ for installation instructions for your platform. ## Getting `kubefed` -Download the client tarball corresponding to Kubernetes version 1.5 -or later -[from the release page](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG.md), -extract the binaries in the tarball to one of the directories -in your `$PATH` and set the executable permission on those binaries. +Download the client tarball corresponding to the latest release and +extract the binaries in the tarball with the commands: -Note: The URL in the curl command below downloads the binaries for -Linux amd64. If you are on a different platform, please use the URL -for the binaries appropriate for your platform. You can find the list -of available binaries on the [release page](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG.md#client-binaries-1). +```shell +# Linux +curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s +https://storage.googleapis.com/kubernetes-release/release/stable.txt)/kubernetes-client-linux-amd64.tar.gz +tar -xzvf kubernetes-client-linux-amd64.tar.gz + +# OS X +curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s +https://storage.googleapis.com/kubernetes-release/release/stable.txt)/kubernetes-client-darwin-amd64.tar.gz +tar -xzvf kubernetes-client-darwin-amd64.tar.gz + +# Windows +curl -LO https://storage.googleapis.com/kubernetes-release/release/$(curl -s +https://storage.googleapis.com/kubernetes-release/release/stable.txt)/kubernetes-client-windows-amd64.tar.gz +tar -xzvf kubernetes-client-windows-amd64.tar.gz +``` + +> Note: The URLs in the curl commands above download the binaries for +`amd64`. If you are on a different architecture, please use a URL +appropriate for your architecture. You can find the list of available +binaries on the +[release page](https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG.md#client-binaries-1). + +Copy the extracted binaries to one of the directories in your `$PATH` +and set the executable permission on those binaries. ```shell -curl -O https://storage.googleapis.com/kubernetes-release/release/{{page.version}}/kubernetes-client-linux-amd64.tar.gz -tar -xzvf kubernetes-client-linux-amd64.tar.gz sudo cp kubernetes/client/bin/kubefed /usr/local/bin sudo chmod +x /usr/local/bin/kubefed sudo cp kubernetes/client/bin/kubectl /usr/local/bin @@ -109,7 +125,7 @@ It must also end with a trailing dot. `kubefed init` sets up the federation control plane in the host cluster and also adds an entry for the federation API server in your -local kubeconfig. Note that in the alpha release in Kubernetes 1.5, +local kubeconfig. Note that in the beta release in Kubernetes 1.6, `kubefed init` does not automatically set the current context to the newly deployed federation. You can set the current context manually by running: @@ -156,13 +172,13 @@ kubefed init fellowship \ --host-cluster-context=rivendell \ --dns-provider="google-clouddns" \ --dns-zone-name="example.com." \ - --apiserver-arg-overrides="--anonymous-auth=false, --v=4" \ + --apiserver-arg-overrides="--anonymous-auth=false,--v=4" \ --controllermanager-arg-overrides="--controllers=services=false" ``` -### Configuring DNS provider +### Configuring a DNS provider -Federated service controller programs a DNS provider to expose +The Federated service controller programs a DNS provider to expose federated services via DNS names. Certain cloud providers automatically provide the configuration required to program the DNS provider if the host cluster's cloud provider is same as the DNS @@ -218,7 +234,7 @@ kubefed init fellowship \ --api-server-advertise-address="10.0.10.20" ``` -#### Dynamic provisioning of etcd storage +#### Provisioning storage for etcd Federation control plane stores its state in [`etcd`](https://coreos.com/etcd/docs/latest/). @@ -231,12 +247,44 @@ federation control plane restarts. On host clusters that support and binds it to a [`PersistentVolumeClaim`](/docs/user-guide/persistent-volumes/#persistentvolumeclaims) to store [`etcd`](https://coreos.com/etcd/docs/latest/) data. If your -host cluster doesn't support dynamic provisioning, then you pass -`--etcd-persistent-storage=false` to `kubefed init` to disable -storage provisioning and provide your own -[`PersistentVolume`](/docs/user-guide/persistent-volumes/#persistent-volumes) and +host cluster doesn't support dynamic provisioning, you can also +statically provision a +[`PersistentVolume`](/docs/user-guide/persistent-volumes/#persistent-volumes). +`kubefed init` creates a +[`PersistentVolumeClaim`](/docs/user-guide/persistent-volumes/#persistentvolumeclaims) +that has the following configuration: + +```yaml +apiVersion: v1 +kind: PersistentVolumeClaim +metadata: + annotations: + volume.alpha.kubernetes.io/storage-class: "yes" + labels: + app: federated-cluster + name: fellowship-federation-apiserver-etcd-claim + namespace: federation-system +spec: + accessModes: + - ReadWriteOnce + resources: + requests: + storage: 10Gi +``` + +To statically provision a +[`PersistentVolume`](/docs/user-guide/persistent-volumes/#persistent-volumes), +you must ensure that the +[`PersistentVolume`](/docs/user-guide/persistent-volumes/#persistent-volumes) +that you create has the matching storage class, access mode and +at least as much capacity as the requested [`PersistentVolumeClaim`](/docs/user-guide/persistent-volumes/#persistentvolumeclaims). +Alternatively, you can disable persistent storage completely +by passing `--etcd-persistent-storage=false` to `kubefed init`. +However, we do not recommended this because your federation control +plane cannot survive restarts in this mode. + ```shell kubefed init fellowship \ --host-cluster-context=rivendell \ @@ -360,9 +408,10 @@ for you. `kube-dns` configuration must be updated in each joining cluster to enable federated service discovery. If the joining Kubernetes cluster -is version 1.5 or newer and your `kubefed` version 1.6 or later, then -this configuration is automatically managed for you when the clusters -are joined or unjoined using `kubefed` `join` or `unjoin` commands. +is version 1.5 or newer and your `kubefed` is version 1.6 or newer, +then this configuration is automatically managed for you when the +clusters are joined or unjoined using `kubefed` `join` or `unjoin` +commands. In all other cases, you must update `kube-dns` configuration manually as described in the @@ -382,7 +431,7 @@ kubefed unjoin gondor --host-cluster-context=rivendell ## Turning down the federation control plane: Proper cleanup of federation control plane is not fully implemented in -this alpha release of `kubefed`. However, for the time being, deleting +this beta release of `kubefed`. However, for the time being, deleting the federation system namespace should remove all the resources except the persistent storage volume dynamically provisioned for the federation control plane's etcd. You can delete the federation