Deployments

The yaml for the existing Deployment is available at /opt/course/16/cleaner.yaml. Persist your changes at /opt/course/16/cleaner-new.yaml on ckad7326 but also make sure the Deployment is running.

# Check the current deployment manifest
cat /opt/course/16/cleaner.yaml

# Copy to a new file
cp /opt/course/16/cleaner.yaml /opt/course/16/cleaner-new.yaml

# Edit the new file as per question requirements
vi /opt/course/16/cleaner-new.yaml

# Apply the new deployment
kubectl apply -f /opt/course/16/cleaner-new.yaml

# Verify that it's running
kubectl get deploy,rs,pods -n <namespace>

Q1 Canary Deployment

On cluster2, a new deployment called cube-alpha-apd has been created in the alpha-ns-apd namespace using the image kodekloud/webapp-color:v2. This deployment will test a newer version of the alpha app.

Configure the deployment in such a way that the alpha-apd-service service routes less than 40% of traffic to the new deployment.

NOTE: - Do not increase the replicas of the ruby-alpha-apd deployment.

root@student-node ~ ➜  k get po -n alpha-ns-apd --show-labels 
NAME                              READY   STATUS    RESTARTS   AGE    LABELS
cube-alpha-apd-6f8fd88867-28n56   1/1     Running   0          2m3s   alpha=v1,pod-template-hash=6f8fd88867
cube-alpha-apd-6f8fd88867-7sbt8   1/1     Running   0          2m3s   alpha=v1,pod-template-hash=6f8fd88867
cube-alpha-apd-6f8fd88867-l26cj   1/1     Running   0          2m3s   alpha=v1,pod-template-hash=6f8fd88867
cube-alpha-apd-6f8fd88867-xwzbt   1/1     Running   0          2m3s   alpha=v1,pod-template-hash=6f8fd88867
cube-alpha-apd-6f8fd88867-z4j4b   1/1     Running   0          2m3s   alpha=v1,pod-template-hash=6f8fd88867
ruby-alpha-apd-684b685879-27kv4   1/1     Running   0          2m4s   alpha=v1,pod-template-hash=684b685879
ruby-alpha-apd-684b685879-7hwpn   1/1     Running   0          2m4s   alpha=v1,pod-template-hash=684b685879
ruby-alpha-apd-684b685879-7q88b   1/1     Running   0          2m3s   alpha=v1,pod-template-hash=684b685879
ruby-alpha-apd-684b685879-g8vvf   1/1     Running   0          2m4s   alpha=v1,pod-template-hash=684b685879
ruby-alpha-apd-684b685879-s2f9f   1/1     Running   0          2m3s   alpha=v1,pod-template-hash=684b685879

root@student-node ~ ➜  k describe svc -n alpha-ns-apd alpha-apd-service 
Name:                     alpha-apd-service
Namespace:                alpha-ns-apd
Labels:                   app=alpha-apd-service
Annotations:              <none>
Selector:                 alpha=v1
Type:                     NodePort
IP Family Policy:         SingleStack
IP Families:              IPv4
IP:                       10.43.70.250
IPs:                      10.43.70.250
Port:                     <unset>  8080/TCP
TargetPort:               8080/TCP
NodePort:                 <unset>  30640/TCP
Endpoints:                10.42.1.12:8080,10.42.1.14:8080,10.42.1.13:8080 + 7 more...
Session Affinity:         None
External Traffic Policy:  Cluster
Internal Traffic Policy:  Cluster
Events:                   <none>

root@student-node ~ ➜  kubectl -n alpha-ns-apd scale deployment cube-alpha-apd --replicas=3
deployment.apps/cube-alpha-apd scaled

root@student-node ~ ➜  k describe svc -n alpha-ns-apd alpha-apd-service 
Name:                     alpha-apd-service
Namespace:                alpha-ns-apd
Labels:                   app=alpha-apd-service
Annotations:              <none>
Selector:                 alpha=v1              # sharing the common label
Type:                     NodePort
IP Family Policy:         SingleStack
IP Families:              IPv4
IP:                       10.43.70.250
IPs:                      10.43.70.250
Port:                     <unset>  8080/TCP
TargetPort:               8080/TCP
NodePort:                 <unset>  30640/TCP
Endpoints:                10.42.1.12:8080,10.42.1.13:8080,10.42.1.15:8080 + 5 more...
Session Affinity:         None
External Traffic Policy:  Cluster
Internal Traffic Policy:  Cluster
Events:                   <none>

root@student-node ~ ➜

Thanks for the detailed output 🙌

Let’s analyze what’s going on:

Current State

Deployments:
ruby-alpha-apd → 5 Pods
cube-alpha-apd → 5 Pods
Service alpha-apd-service:
Selector → alpha=v1
That means all 10 Pods (5 ruby + 5 cube) are matching.
So traffic is currently distributed \~50/50 (because both sets have the same number of replicas).

Requirement

Configure the deployment so that alpha-apd-service routes less than 40% traffic to the new cube-alpha-apd deployment. ⚠️ You cannot increase ruby-alpha-apd replicas.

This means we need to reduce cube-alpha-apd replicas, so it makes up less than 40% of the total Pods.

Math

ruby-alpha-apd = 5 replicas
If cube-alpha-apd = 2 replicas → Total = 7 Pods
Cube share = 2/7 ≈ 28% ✅ (less than 40%)
If cube-alpha-apd = 3 replicas → Total = 8 Pods
Cube share = 3/8 = 37.5% ✅ (still less than 40%)
If cube-alpha-apd = 4 replicas → Total = 9 Pods
Cube share = 4/9 ≈ 44% ❌ (too high)

So you can scale cube-alpha-apd down to 2 or 3 replicas.

Command

To scale to 3 replicas (safe, closer to 40% but still below):

kubectl -n alpha-ns-apd scale deployment cube-alpha-apd --replicas=3

Or scale to 2 replicas (more conservative, \~28%):

kubectl -n alpha-ns-apd scale deployment cube-alpha-apd --replicas=2

Verify

kubectl -n alpha-ns-apd get pods -o wide
kubectl -n alpha-ns-apd describe svc alpha-apd-service

You should see only 8 pods (5 ruby + 3 cube) or 7 pods (5 ruby + 2 cube) behind the service.

Q2 Canary Deployment

A new deployment called frontend-v2 has been created in the default namespace using the image kodekloud/webapp-color:v2. This deployment will be used to test a newer version of the same app.

Configure the deployment in such a way that the service called frontend-service routes less than 20% of traffic to the new deployment. Do not increase the replicas of the frontend deployment.

controlplane ~ ➜  k get deploy
NAME          READY   UP-TO-DATE   AVAILABLE   AGE
frontend      5/5     5            5           11m
frontend-v2   2/2     2            2           8m18s

controlplane ~ ➜  k get po --show-labels 
NAME                           READY   STATUS    RESTARTS   AGE     LABELS
frontend-8b5db9bd-6x2fk        1/1     Running   0          11m     app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-8b5db9bd-c285m        1/1     Running   0          11m     app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-8b5db9bd-hsxfs        1/1     Running   0          11m     app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-8b5db9bd-kgzvj        1/1     Running   0          11m     app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-8b5db9bd-qlrsf        1/1     Running   0          11m     app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-v2-79b6c9cff4-9ptf5   1/1     Running   0          8m23s   app=frontend,pod-template-hash=79b6c9cff4,version=v2
frontend-v2-79b6c9cff4-rbqsb   1/1     Running   0          8m23s   app=frontend,pod-template-hash=79b6c9cff4,version=v2

controlplane ~ ➜  k describe svc frontend-service 
Name:                     frontend-service
Namespace:                default
Labels:                   app=myapp
Annotations:              <none>
Selector:                 app=frontend    # sharing the common label
Type:                     NodePort
IP Family Policy:         SingleStack
IP Families:              IPv4
IP:                       172.20.236.179
IPs:                      172.20.236.179
Port:                     <unset>  8080/TCP
TargetPort:               8080/TCP
NodePort:                 <unset>  30080/TCP
Endpoints:                172.17.0.7:8080,172.17.0.5:8080,172.17.0.6:8080 + 4 more...
Session Affinity:         None
External Traffic Policy:  Cluster
Internal Traffic Policy:  Cluster
Events:                   <none>

controlplane ~ ➜  k scale deployment frontend-v2 --replicas 1
deployment.apps/frontend-v2 scaled

controlplane ~ ➜  k get po --show-labels
NAME                           READY   STATUS    RESTARTS   AGE   LABELS
frontend-8b5db9bd-6x2fk        1/1     Running   0          13m   app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-8b5db9bd-c285m        1/1     Running   0          13m   app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-8b5db9bd-hsxfs        1/1     Running   0          13m   app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-8b5db9bd-kgzvj        1/1     Running   0          13m   app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-8b5db9bd-qlrsf        1/1     Running   0          13m   app=frontend,pod-template-hash=8b5db9bd,version=v1
frontend-v2-79b6c9cff4-rbqsb   1/1     Running   0          10m   app=frontend,pod-template-hash=79b6c9cff4,version=v2

controlplane ~ ➜

We have now established that the new version v2 of the application is working as expected.

We can now safely redirect all users to the v2 version.

controlplane ~ ➜  k edit svc frontend-service 
service/frontend-service edited

controlplane ~ ➜  k describe svc frontend-service 
Name:                     frontend-service
Namespace:                default
Labels:                   app=myapp
Annotations:              <none>
Selector:                 app=frontend,version=v2       # version: v2 added now.
Type:                     NodePort
IP Family Policy:         SingleStack
IP Families:              IPv4
IP:                       172.20.236.179
IPs:                      172.20.236.179
Port:                     <unset>  8080/TCP
TargetPort:               8080/TCP
NodePort:                 <unset>  30080/TCP
Endpoints:                172.17.0.10:8080
Session Affinity:         None
External Traffic Policy:  Cluster
Internal Traffic Policy:  Cluster
Events:                   <none>

controlplane ~ ➜

Scale down the v1 version of the apps to 0 replicas and scale up the new(v2) version to 5 replicas.

controlplane ~ ➜  k scale deployment frontend-v2 --replicas 5
deployment.apps/frontend-v2 scaled

controlplane ~ ➜  k scale deployment frontend --replicas 0
deployment.apps/frontend scaled

controlplane ~ ➜  k get po --show-labels
NAME                           READY   STATUS    RESTARTS   AGE   LABELS
frontend-v2-79b6c9cff4-6d9c5   1/1     Running   0          45s   app=frontend,pod-template-hash=79b6c9cff4,version=v2
frontend-v2-79b6c9cff4-8c7gv   1/1     Running   0          45s   app=frontend,pod-template-hash=79b6c9cff4,version=v2
frontend-v2-79b6c9cff4-kmph2   1/1     Running   0          45s   app=frontend,pod-template-hash=79b6c9cff4,version=v2
frontend-v2-79b6c9cff4-rbqsb   1/1     Running   0          17m   app=frontend,pod-template-hash=79b6c9cff4,version=v2
frontend-v2-79b6c9cff4-z76sf   1/1     Running   0          45s   app=frontend,pod-template-hash=79b6c9cff4,version=v2

controlplane ~ ➜

Now delete the deployment called frontend completely.

controlplane ~ ➜  k delete deployments.apps frontend
deployment.apps "frontend" deleted

Q3

An application called results-apd is running on cluster2. In the weekly meeting, the team decides to upgrade the version of the existing image to 1.23.3 and wants to store the new version of the image in a file /root/records/new-image-records.txt on the cluster2-controlplane instance.

echo "1.23.3" > /root/records/new-image-records.txt   # wrong, but is tag only.
echo "nginx:1.23.3" > /root/records/new-image-records.txt

Q4 Deployment is paused.

cluster1-controlplane ~ ➜  k get po -n kube-system   # No clue
NAMESPACE     NAME                                            READY   STATUS    RESTARTS   AGE
kube-system   calico-kube-controllers-5745477d4d-bs7tc        1/1     Running   0          117m
kube-system   canal-5k7vk                                     2/2     Running   0          117m
kube-system   canal-jnvlq                                     2/2     Running   0          117m
kube-system   canal-v5k88                                     2/2     Running   0          117m
kube-system   coredns-7484cd47db-ftpkp                        1/1     Running   0          117m
kube-system   coredns-7484cd47db-qqkdp                        1/1     Running   0          117m
kube-system   etcd-cluster1-controlplane                      1/1     Running   0          117m
kube-system   kube-apiserver-cluster1-controlplane            1/1     Running   0          117m
kube-system   kube-controller-manager-cluster1-controlplane   1/1     Running   0          117m
kube-system   kube-proxy-l75zs                                1/1     Running   0          117m
kube-system   kube-proxy-pxd5v                                1/1     Running   0          117m
kube-system   kube-proxy-sc89b                                1/1     Running   0          117m
kube-system   kube-scheduler-cluster1-controlplane            1/1     Running   0          117m
kube-system   metrics-server-6f7dd4c4c4-2m9jn                 1/1     Running   0          97m

cluster1-controlplane ~ ➜  k get deploy black-cka25-trb 
NAME              READY   UP-TO-DATE   AVAILABLE   AGE             # Problem UP-TO-DATE=0
black-cka25-trb   1/1     0            1           76s

cluster1-controlplane ~ ➜  k describe deployments.apps black-cka25-trb 
Name:                   black-cka25-trb
Replicas:               1 desired | 0 updated | 1 total | 1 available | 0 unavailable
Conditions:
  Type           Status   Reason
  ----           ------   ------
  Available      True     MinimumReplicasAvailable
  Progressing    Unknown  DeploymentPaused                         # Found the culprit
OldReplicaSets:  black-cka25-trb-7bdc648c8c (1/1 replicas created)
NewReplicaSet:   <none>

cluster1-controlplane ~ ➜  k get deploy black-cka25-trb -o yaml
apiVersion: apps/v1
spec:
  paused: true                                                    # Spotted
  replicas: 1

cluster1-controlplane ~ ➜  k get po black-cka25-trb-7bdc648c8c-q94t9 -o yaml
apiVersion: v1
kind: Pod
spec:
  nodeName: cluster1-node02

cluster1-controlplane ~ ➜  k rollout status deployment black-cka25-trb  # Oh, I got it...
Waiting for deployment "black-cka25-trb" rollout to finish: 0 out of 1 new replicas have been updated...
^C

cluster1-controlplane ~ ➜  k get pods -o wide | grep black-cka25-trb
black-cka25-trb-7bdc648c8c-q94t9           1/1     Running   0               9m48s   172.17.2.20   cluster1-node02   <none>           <none>

cluster1-controlplane ~ ➜  k logs black-cka25-trb-7bdc648c8c-q94t9 

cluster1-controlplane ~ ➜  k rollout restart deployment black-cka25-trb 
error: deployments.apps "black-cka25-trb" can't restart paused deployment (run rollout resume first)

cluster1-controlplane ~ ✖ k rollout resume deployment black-cka25-trb 
deployment.apps/black-cka25-trb resumed

cluster1-controlplane ~ ➜  k rollout restart deployment black-cka25-trb 
deployment.apps/black-cka25-trb restarted

cluster1-controlplane ~ ➜  k get deploy black-cka25-trb 
NAME              READY   UP-TO-DATE   AVAILABLE   AGE
black-cka25-trb   1/1     1            1           18m

Q5: Replica=0

stream-deployment deployment is not up to date. observed 0 under the UP-TO-DATE it should be 1 , Troubleshoot, fix the issue and make sure deployment is up to date.

controlplane:~$ k get po
No resources found in default namespace.
controlplane:~$ k get deployments.apps 
NAME                READY   UP-TO-DATE   AVAILABLE   AGE
stream-deployment   0/0     0            0           4m25s
controlplane:~$ k describe deployments.apps stream-deployment 
Name:                   stream-deployment
Replicas:               0 desired | 0 updated | 0 total | 0 available | 0 unavailable   # replica is 0
NewReplicaSet:   stream-deployment-79cb7b68c (0/0 replicas created)
Events:          <none>

controlplane:~$ k edit deployments.apps stream-deployment     # change replica: 1
deployment.apps/stream-deployment edited
controlplane:~$ k get deployments.apps 
NAME                READY   UP-TO-DATE   AVAILABLE   AGE
stream-deployment   0/1     1            0           5m5s
controlplane:~$ k get deployments.apps 
NAME                READY   UP-TO-DATE   AVAILABLE   AGE
stream-deployment   1/1     1            1           5m9s
controlplane:~$

Q6

The deployment named video-app has experienced multiple rolling updates and rollbacks. Your task is to total revision of this deployment and record the image name used in 3rd revision to file app-file.txt in this format REVISION_TOTAL_COUNT,IMAGE_NAME.

controlplane:~$ k rollout history deployment video-app 
deployment.apps/video-app 
REVISION  CHANGE-CAUSE
1         <none>
2         <none>
3         <none>

controlplane:~$ k rollout history deployment video-app --revision 3
deployment.apps/video-app with revision #3
Pod Template:
  Labels:       app=video-app
        pod-template-hash=775488848c
  Containers:
   redis:
    Image:      redis:7.0.13
    Port:       <none>
    Host Port:  <none>
    Environment:        <none>
    Mounts:     <none>
  Volumes:      <none>
  Node-Selectors:       <none>
  Tolerations:  <none>

controlplane:~$ echo "3,redis:7.0.13" > app-file.txt
controlplane:~$ cat app-file.txt 
3,redis:7.0.13
controlplane:~$

Q7

Create a Redis deployment in the default namespace with the following specifications:

Name: redis Image: redis:alpine Replicas: 1 Labels: app=redis CPU Request: 0.2 CPU (200m) Container Port: 6379 Volumes: - An emptyDir volume named data, mounted at /redis-master-data. - A ConfigMap volume named redis-config, mounted at /redis-master.The ConfigMap has already been created for you. Do not create it again.

controlplane ~ ➜  k replace -f 5.yaml --force
deployment.apps/redis replaced

controlplane ~ ➜  k get deploy
NAME           READY   UP-TO-DATE   AVAILABLE   AGE
nginx-deploy   4/4     4            4           14m
redis          1/1     1            1           6s

controlplane ~ ➜  k get cm 
NAME               DATA   AGE
kube-root-ca.crt   1      135m
redis-config       1      12m

controlplane ~ ➜  cat 5.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: redis
  name: redis
spec:
  replicas: 1
  selector:
    matchLabels:
      app: redis
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: redis
    spec:
      volumes:
        - name: data
          emptyDir: {}
        - name: redis-config    # I just put random name here, the question becomes incorrect.
          configMap:
            name: redis-config
      containers:
      - image: redis:alpine
        name: redis
        volumeMounts:
          - name: redis-config
            mountPath: /redis-master
          - name: data
            mountPath: /redis-master-data
        resources:
          request: 
            cpu: "200m"
        ports:
        - containerPort: 6379
        resources: {}
status: {}

controlplane ~ ➜

Q8

From student-node ssh cluster1-controlplane to solve this question.

Create a deployment named logging-deployment in the namespace logging-ns with 1 replica, with the following specifications:

The main container should be named app-container, use the image busybox, and should start by creating a log directory /var/log/app and run the below command to simulate generating logs :

while true; do 
  echo "Log entry" >> /var/log/app/app.log
  sleep 5
done

Add a co-located container named log-agent that also uses the busybox image and runs the commands:

touch /var/log/app/app.log
tail -f /var/log/app/app.log

log-agent logs should display the entries logged by the main app-container

cluster1-controlplane ~ ➜  cat 2.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: logging-deployment
  name: logging-deployment
  namespace: logging-ns
spec:
  replicas: 1
  selector:
    matchLabels:
      app: logging-deployment
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: logging-deployment
    spec:
      volumes:
        - name: abc
          emptyDir: {}
      containers:
      - image: busybox
        name: app-container
        volumeMounts:
          - name: abc
            mountPath: /var/log/app
        command:
          - sh
          - -c
        args:
          - while true; do echo "Log entry" >> /var/log/app/app.log; sleep 5; done
      - image: busybox
        volumeMounts:
          - name: abc
            mountPath: /var/log/app
        name: log-agent
        command:
          - sh
          - -c
          - touch /var/log/app/app.log; tail -f /var/log/app/app.log
status: {}

cluster1-controlplane ~ ➜  k logs -n logging-ns logging-deployment-7bdd98cff6-z8rjk -c log-agent
Log entry
Log entry