Prerequisites
Assignment
- Lets start by creating a deployment and inspect the repliacesets.
1️⃣ Create a simple deployment using nginx using imperative command and also create a manifest file.
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| kubectl create deployment nginx --image=nginx --dry-run=client -o yaml | tee nginx-deployment.yaml | kubectl apply -f -
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2️⃣ List all the deployments and replicasets.
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| kubectl get deployment
kubectl get replicaset
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3️⃣ Query the pods and check that these pods will be named with the name of the deployment, replicaSet and a unique identifier.
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| kubectl get pods -o wide
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4️⃣ Check the initial rollout history and annote this to make use of this record.
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| kubectl rollout history deployment/nginx
kubectl annotate deployment/nginx kubernetes.io/change-cause="initial deployment"
kubectl rollout history deployment/nginx
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5️⃣ Scale the number of replicas and monitor the change.
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| kubectl scale deployment/nginx --replicas=10; watch kubectl get pods -o wide
kubectl get deployment -o wide
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6️⃣ Modify the nginx-deployment.yaml file to increase the replica count to 12.
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| cat <<EOF > nginx-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: nginx
name: nginx
spec:
replicas: 12
selector:
matchLabels:
app: nginx
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: nginx
spec:
containers:
- image: nginx
name: nginx
resources: {}
status: {}
EOF
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| kubectl apply -f nginx-deployment.yaml; watch kubectl get pods -o wide
kubectl get deployments -o wide
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7️⃣ Check if the rollout history has changed.
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| kubectl rollout history deployment/nginx
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8️⃣ Modify the deployment to use a different image nginx:stable and check the rollout history.
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| cat <<EOF > nginx-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: nginx
name: nginx
spec:
replicas: 12
selector:
matchLabels:
app: nginx
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: nginx
spec:
containers:
- image: nginx:stable
name: nginx
resources: {}
status: {}
EOF
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| kubectl apply -f nginx-deployment.yaml && kubectl rollout status deployment/nginx
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| kubectl get deployments -o wide
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9️⃣ Annotate the newly added entry in the rollout history.
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| kubectl annotate deployment/nginx kubernetes.io/change-cause="change image to nginx:stable"
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| kubectl rollout history deployment/nginx
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🔟 Change the image using CLI and watch the rollout status.
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| kubectl set image deployment/nginx nginx=nginx:alpine && kubectl rollout status deployment/nginx
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| kubectl annotate deployment/nginx kubernetes.io/change-cause="change image to nginx:alpine"
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| kubectl rollout history deployment/nginx
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1️⃣1️⃣. Describe the deployment to check the reference to the new and old replicasets.
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| kubectl describe deployment/nginx
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| kubectl get replicaset -o wide
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1️⃣2️⃣. Change the image name to an invalid value and verify how it safeguards the deployment.
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| kubectl set image deployment/nginx nginx=nginx:bananas && watch kubectl get pods -o wide
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| kubectl annotate deployment/nginx kubernetes.io/change-cause="change image to nginx:bananas - failed"
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| kubectl describe deployment/nginx
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1️⃣3️⃣. Undo the change using rollout option.
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| kubectl rollout undo deployment/nginx && kubectl rollout status deployment/nginx
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1️⃣4️⃣. Undo Rollout to a specific version and check the rollout history.
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| kubectl rollout undo deployment/nginx --to-revision=1 && kubectl rollout status deployment/nginx
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| kubectl get replicaset -o wide
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| kubectl rollout history deployment/nginx
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CleanUp
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| kubectl delete deployment/nginx --now
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