Datasets:
roanbrasil
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devops-gitops-corpus

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```
Result: The deployment then creates the single Redis master pod.
3. To verify that the redis-master pod is running, list the pods you created in cluster with the `kubectl get pods` command:
```console
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
redis-master-5b97bdb85f-vvk28 1/1 Running 0 35m
...
```
Result: You'll see a single Redis master pod and the machine where the pod is running after the pod gets placed (may take up to thirty seconds).
4. To verify what containers are running in the redis-master pod, you can SSH to that machine with `gcloud compute ssh --zone` *`zone_name`* *`host_name`* and then run `docker ps`:
```console
me@workstation$ gcloud compute ssh --zone us-central1-b kubernetes-node-bz1p
me@kubernetes-node-3:~$ sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS
d5c458dabe50 redis "/entrypoint.sh redis" 5 minutes ago Up 5 minutes
```
Note: The initial `docker pull` can take a few minutes, depending on network conditions.
### Step Two: Create the Redis master service <a id="step-two"></a>
A Kubernetes [service](https://kubernetes.io/docs/concepts/services-networking/service/) is a named load balancer that proxies traffic to one or more pods. The services in a Kubernetes cluster are discoverable inside other pods via environment variables or DNS.
Services find the pods to load balance based on pod labels. The pod that you created in Step One has the label `app=redis` and `role=master`. The selector field of the service determines which pods will receive the traffic sent to the service.
1. Use the [redis-master-service.yaml](redis-master-service.yaml) file to create the service in your Kubernetes cluster by running the `kubectl create -f` *`filename`* command:
```console
$ kubectl create -f guestbook-go/redis-master-service.yaml
```
2. To verify that the redis-master service is up, list the services you created in the cluster with the `kubectl get services` command:
```console
$ kubectl get services
NAME CLUSTER_IP EXTERNAL_IP PORT(S) SELECTOR AGE
redis-master 10.0.136.3 <none> 6379/TCP app=redis,role=master 1h
...
```
Result: All new pods will see the `redis-master` service running on the host (`$REDIS_MASTER_SERVICE_HOST` environment variable) at port 6379, or running on `redis-master:6379`. After the service is created, the service proxy on each node is configured to set up a proxy on the specified port (in our example, that's...
### Step Three: Create the Redis replica pods <a id="step-three"></a>
The Redis master we created earlier is a single pod (REPLICAS = 1), while the Redis read replicas we are creating here are 'replicated' pods. In Kubernetes, a replication controller is responsible for managing the multiple instances of a replicated pod.
1. Use the file [redis-replica-controller.yaml](redis-replica-controller.yaml) to create the replication controller by running the `kubectl create -f` *`filename`* command:
```console
$ kubectl create -f guestbook-go/redis-replica-controller.yaml
```
2. To verify that the redis-replica controller is running, run the `kubectl get rc` command:
```console
$ kubectl get rc
CONTROLLER CONTAINER(S) IMAGE(S) SELECTOR REPLICAS
redis-replica redis-replica registry.k8s.io/redis-slave:v2 app=redis,role=replica 2
...
```
Result: The replication controller creates and configures the Redis replica pods through the redis-master service (name:port pair, in our example that's `redis-master:6379`).
Example:
The Redis replicas get started by the replication controller with the following command:
```console
redis-server --replicaof redis-master 6379
```
3. To verify that the Redis master and replicas pods are running, run the `kubectl get pods` command:
```console
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
redis-master-5b97bdb85f-vvk28 1/1 Running 0 35m
redis-replica-b6wj4 1/1 Running 0 1m
redis-replica-iai40 1/1 Running 0 1m
...
```
Result: You see the single Redis master and two Redis replica pods.
### Step Four: Create the Redis replica service <a id="step-four"></a>
Just like the master, we want to have a service to proxy connections to the read replicas. In this case, in addition to discovery, the Redis replica service provides transparent load balancing to clients.
1. Use the [redis-replica-service.yaml](redis-replica-service.yaml) file to create the Redis replica service by running the `kubectl create -f` *`filename`* command: