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The important thing to note here is the `selector`. It is a query over labels, that identifies the set of _Pods_ contained by the _Service_. In this case the selector is `name: hazelcast`. If you look at the Replication Controller specification below, you'll see that the pod has the corresponding label, so it will be...
Create this service as follows:
```sh
$ kubectl create -f examples/storage/hazelcast/hazelcast-service.yaml
```
### Adding replicated nodes
The real power of Kubernetes and Hazelcast lies in easily building a replicated, resizable Hazelcast cluster.
In Kubernetes a _[_Deployment_](https://kubernetes.io/docs/user-guide/deployments.md)_ is responsible for replicating sets of identical pods. Like a _Service_ it has a selector query which identifies the members of its set. Unlike a _Service_ it also has a desired number of replicas, and it will create or delete _Pods...
Deployments will "adopt" existing pods that match their selector query, so let's create a Deployment with a single replica to adopt our existing Hazelcast Pod.
<!-- BEGIN MUNGE: EXAMPLE hazelcast-controller.yaml -->
```yaml
apiVersion: "apps/v1" # for k8s versions before 1.9.0 use apps/v1beta2 and before 1.8.0 use extensions/v1beta1
kind: Deployment
metadata:
name: hazelcast
labels:
name: hazelcast
spec:
selector:
matchLabels:
name: hazelcast
template:
metadata:
labels:
name: hazelcast
spec:
containers:
- name: hazelcast
image: quay.io/pires/hazelcast-kubernetes:0.8.0
imagePullPolicy: Always
env:
- name: "DNS_DOMAIN"
value: "cluster.local"
ports:
- name: hazelcast
containerPort: 5701
```
[Download example](hazelcast-deployment.yaml?raw=true)
<!-- END MUNGE: EXAMPLE hazelcast-controller.yaml -->
You may note that we tell Kubernetes that the container exposes the `hazelcast` port.
The bulk of the replication controller config is actually identical to the Hazelcast pod declaration above, it simply gives the controller a recipe to use when creating new pods. The other parts are the `selector` which contains the controller's selector query, and the `replicas` parameter which specifies the desired ...
Last but not least, we set `DNS_DOMAIN` environment variable according to your Kubernetes clusters DNS configuration.
Create this controller:
```sh
$ kubectl create -f examples/storage/hazelcast/hazelcast-deployment.yaml
```
After the controller provisions successfully the pod, you can query the service endpoints:
```sh
$ kubectl get endpoints hazelcast -o yaml
apiVersion: v1
kind: Endpoints
metadata:
creationTimestamp: 2017-03-15T09:40:11Z
labels:
name: hazelcast
name: hazelcast
namespace: default
resourceVersion: "65060"
selfLink: /api/v1/namespaces/default/endpoints/hazelcast
uid: 62645b71-0963-11e7-b39c-080027985ce6
subsets:
- addresses:
- ip: 172.17.0.2
nodeName: minikube
targetRef:
kind: Pod
name: hazelcast-4195412960-mgqtk
namespace: default
resourceVersion: "65058"
uid: 7043708f-0963-11e7-b39c-080027985ce6
ports:
- port: 5701
protocol: TCP
```
You can see that the _Service_ has found the pod created by the replication controller.
Now it gets even more interesting. Let's scale our cluster to 2 pods:
```sh
$ kubectl scale deployment hazelcast --replicas 2
```
Now if you list the pods in your cluster, you should see two hazelcast pods: