Merge pull request #324 from justinsb/docs_aug16a

Document cleaned up upgrade command

cmd/kops/upgrade_cluster.go

@@ -81,7 +81,8 @@ func (c *UpgradeClusterCmd) Run() error {
 
 	if len(actions) == 0 {
 		// TODO: Allow --force option to force even if not needed?
-		fmt.Printf("\nNo upgrade required\n")
+		// Note stderr - we try not to print to stdout if no update is needed
+		fmt.Fprintf(os.Stderr, "\nNo upgrade required\n")
 		return nil
 	}
 

docs/upgrade.md

@@ -0,0 +1,28 @@
+## Upgrading Kubernetes
+
+Upgrading Kubernetes is easy with kops.  The cluster spec contains a KubernetesVersion, so you
+can simply edit it with `kops edit`, and apply the updated configuration to your cluster.
+The `kops upgrade` command also automates checking for and applying updates.
+
+Note: if you want to upgrade from a `kube-up` installation, please see the instructions for
+[how to upgrade kubernetes installed with kube-up](upgrade_from_k8s_12.md).
+
+### Manual update
+
+* `kops edit cluster $NAME`
+* set the KubernetesVersion to the target version (e.g. `v1.3.5`)
+* `kops update cluster $NAME` to preview, then `kops update cluster $NAME --yes`
+* `kops rolling-update cluster $NAME` to preview, then `kops rolling-update cluster $NAME --yes`
+
+### Automated update
+
+* `kops upgrade cluster $NAME` to preview, then `kops upgrade cluster $NAME --yes`
+
+In future the upgrade step will likely perform the update immediately (and possibly even without a
+node restart), but currently you must:
+
+* `kops update cluster $NAME` to preview, then `kops update cluster $NAME --yes`
+* `kops rolling-update cluster $NAME` to preview, then `kops rolling-update cluster $NAME --yes`
+
+
+upgrade uses the latest Kuberentes stable release, published at `https://storage.googleapis.com/kubernetes-release/release/stable.txt`