Update statefulset.md (#3732)

Following links were broken on the Stateful Set page

Link to "Force deleting Stateful Sets"
Link to Headless service.
Link to cluser domain
This commit is contained in:
cbatra
2017-05-12 15:37:47 -07:00
committed by Andrew Chen
parent d286e4036b
commit 5aab4012c4
@@ -47,7 +47,7 @@ provides a set of stateless replicas. Controllers such as
* As with all alpha/beta resources, you can disable StatefulSet through the `--runtime-config` option passed to the apiserver.
* The storage for a given Pod must either be provisioned by a [PersistentVolume Provisioner](http://releases.k8s.io/{{page.githubbranch}}/examples/persistent-volume-provisioning/README.md) based on the requested `storage class`, or pre-provisioned by an admin.
* Deleting and/or scaling a StatefulSet down will *not* delete the volumes associated with the StatefulSet. This is done to ensure data safety, which is generally more valuable than an automatic purge of all related StatefulSet resources.
* StatefulSets currently require a [Headless Service](/docs/user-guide/services/#headless-services) to be responsible for the network identity of the Pods. You are responsible for creating this Service.
* StatefulSets currently require a [Headless Service](/docs/concepts/services-networking/service/#headless-services) to be responsible for the network identity of the Pods. You are responsible for creating this Service.
* Updating an existing StatefulSet is currently a [manual process](/docs/tutorials/stateful-application/basic-stateful-set/#updating-containers).
## Components
@@ -124,10 +124,10 @@ Each Pod in a StatefulSet derives its hostname from the name of the StatefulSet
and the ordinal of the Pod. The pattern for the constructed hostname
is `$(statefulset name)-$(ordinal)`. The example above will create three Pods
named `web-0,web-1,web-2`.
A StatefulSet can use a [Headless Service](/docs/user-guide/services/#headless-services)
A StatefulSet can use a [Headless Service](/docs/concepts/services-networking/service/#headless-services)
to control the domain of its Pods. The domain managed by this Service takes the form:
`$(service name).$(namespace).svc.cluster.local`, where "cluster.local"
is the [cluster domain](http://releases.k8s.io/{{page.githubbranch}}/build/kube-dns/README.md#how-do-i-configure-it).
is the [cluster domain](http://releases.k8s.io/{{page.githubbranch}}/cluster/addons/dns/README.md).
As each Pod is created, it gets a matching DNS subdomain, taking the form:
`$(podname).$(governing service domain)`, where the governing service is defined
by the `serviceName` field on the StatefulSet.
@@ -142,7 +142,7 @@ Cluster Domain | Service (ns/name) | StatefulSet (ns/name) | StatefulSet Domain
kube.local | foo/nginx | foo/web | nginx.foo.svc.kube.local | web-{0..N-1}.nginx.foo.svc.kube.local | web-{0..N-1} |
Note that Cluster Domain will be set to `cluster.local` unless
[otherwise configured](http://releases.k8s.io/{{page.githubbranch}}/build/kube-dns/README.md#how-do-i-configure-it).
[otherwise configured](http://releases.k8s.io/{{page.githubbranch}}/cluster/addons/dns/README.md).
### Stable Storage
@@ -161,7 +161,7 @@ This must be done manually.
* Before a scaling operation is applied to a Pod, all of its predecessors must be Running and Ready.
* Before a Pod is terminated, all of its successors must be completely shutdown.
The StatefulSet should not specify a `pod.Spec.TerminationGracePeriodSeconds` of 0. This practice is unsafe and strongly discouraged. For further explanation, please refer to [force deleting StatefulSet Pods](/docs/tasks/manage-stateful-set/delete-pods/#deleting-pods).
The StatefulSet should not specify a `pod.Spec.TerminationGracePeriodSeconds` of 0. This practice is unsafe and strongly discouraged. For further explanation, please refer to [force deleting StatefulSet Pods](/docs/tasks/run-application/force-delete-stateful-set-pod/).
When the nginx example above is created, three Pods will be deployed in the order
web-0, web-1, web-2. web-1 will not be deployed before web-0 is