devops-exercises/topics/kubernetes/solutions/replicaset_02_solution.md

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## ReplicaSet 02 - Solution
1. Create a ReplicaSet with 2 replicas. The app can be anything.
```
cat >> rs.yaml <<EOL
apiVersion: apps/v1
kind: ReplicaSet
metadata:
name: web
labels:
app: somewebapp
type: web
spec:
replicas: 2
selector:
matchLabels:
type: web
template:
metadata:
labels:
type: web
spec:
containers:
- name: httpd
image: registry.redhat.io/rhscl/httpd-24-rhel7
EOL
kubectl apply -f rs.yaml
```
2. Verify a ReplicaSet was created and there are 2 replicas
```
kubectl get rs
# OR a more specific way: kubectl get -f rs.yaml
```
3. Remove the ReplicaSet but NOT the pods it created
```
kubectl delete -f rs.yaml --cascade=false
```
4. Verify you've deleted the ReplicaSet but the Pods are still running
```
kubectl get rs # no replicas
kubectl get po # Pods still running
```
5. Create again the same ReplicaSet, without changing anything
```
kubectl apply -f rs.yaml
```
6. Verify that the ReplicaSet used the existing Pods and didn't create new Pods
```
kubectl describe rs web # You should see there are no new events and if you list the pods with 'kubectl get po -f rs.yaml` you'll see they have the same names
```