learning|learning kubernetes by minikube, 3 learningkubernetesbyminikube|3

Goals

Understand the basics of the deployment and service
Create our deployment using YAML
Execute our deployment using YAML
Verify that the application is working as expected
Scale the helloworld application

1 Understand the basics of the deployment and service run kubectl get deploy/hw -o yaml. This will return the YAML that composes the helloworld service:

localhost:~ xunyang$ kubectl run hw --image=karthequian/helloworld --port=80 deployment.apps "hw" created localhost:~ xunyang$ kubectl get deployment/hw -o yaml apiVersion: extensions/v1beta1 kind: Deployment metadata: annotations: deployment.kubernetes.io/revision: "1" creationTimestamp: 2018-04-16T04:41:05Z generation: 1 labels: run: hw name: hw namespace: default resourceVersion: "11258" selfLink: /apis/extensions/v1beta1/namespaces/default/deployments/hw uid: 5f8fbd84-4130-11e8-a846-0800272fd392 spec: progressDeadlineSeconds: 600 replicas: 1 revisionHistoryLimit: 10 selector: matchLabels: run: hw strategy: rollingUpdate: maxSurge: 1 maxUnavailable: 1 type: RollingUpdate template: metadata: creationTimestamp: null labels: run: hw spec: containers: - image: karthequian/helloworld imagePullPolicy: Always name: hw ports: - containerPort: 80 protocol: TCP resources: {} terminationMessagePath: /dev/termination-log terminationMessagePolicy: File dnsPolicy: ClusterFirst restartPolicy: Always schedulerName: default-scheduler securityContext: {} terminationGracePeriodSeconds: 30 status: availableReplicas: 1 conditions: - lastTransitionTime: 2018-04-16T04:41:05Z lastUpdateTime: 2018-04-16T04:41:05Z message: Deployment has minimum availability. reason: MinimumReplicasAvailable status: "True" type: Available - lastTransitionTime: 2018-04-16T04:41:05Z lastUpdateTime: 2018-04-16T04:41:10Z message: ReplicaSet "hw-596b578c58" has successfully progressed. reason: NewReplicaSetAvailable status: "True" type: Progressing observedGeneration: 1 readyReplicas: 1 replicas: 1 updatedReplicas: 1

The Kubernetes service also comprises YAML.
run kubectl get service hw -o yaml

localhost:~ xunyang$ kubectl expose deployment hw --type=NodePort service "hw" exposed localhost:~ xunyang$ kubectl get services NAMETYPECLUSTER-IPEXTERNAL-IPPORT(S)AGE hwNodePort10.107.135.1480:30764/TCP0s kubernetesClusterIP10.96.0.1443/TCP19h localhost:~ xunyang$ kubectl get service hw -o yaml apiVersion: v1 kind: Service metadata: creationTimestamp: 2018-04-16T04:44:21Z labels: run: hw name: hw namespace: default resourceVersion: "11471" selfLink: /api/v1/namespaces/default/services/hw uid: d4c8b9c5-4130-11e8-a846-0800272fd392 spec: clusterIP: 10.107.135.14 externalTrafficPolicy: Cluster ports: - nodePort: 30764 port: 80 protocol: TCP targetPort: 80 selector: run: hw sessionAffinity: None type: NodePort status: loadBalancer: {}

2 Create our deployment using YAML 【learning|learning kubernetes by minikube, 3】create helloworld-all.yaml file, content as below

apiVersion: apps/v1beta1 kind: Deployment metadata: name: helloworld-all-deployment spec: selector: matchLabels: app: helloworld replicas: 1 # tells deployment to run 1 pods matching the template template: # create pods using pod definition in this template metadata: labels: app: helloworld spec: containers: - name: helloworld image: karthequian/helloworld:latest ports: - containerPort: 80 --- apiVersion: v1 kind: Service metadata: name: helloworld-all-service spec: # if your cluster supports it, uncomment the following to automatically create # an external load-balanced IP for the frontend service. type: LoadBalancer ports: - port: 80 protocol: TCP targetPort: 80 selector: app: helloworld

3 Execute our deployment using YAML

localhost:~ xunyang$ kubectl create -f helloworld-all.yaml deployment.apps "helloworld-all-deployment" created service "helloworld-all-service" created localhost:~ xunyang$ kubectlget all NAMEREADYSTATUSRESTARTSAGE helloworld-all-deployment-7c46b4c7dc-2x7561/1Running01sNAMETYPECLUSTER-IPEXTERNAL-IPPORT(S)AGE helloworld-all-serviceLoadBalancer10.98.124.8280:30100/TCP1s kubernetesClusterIP10.96.0.1443/TCP1mNAMEDESIREDCURRENTUP-TO-DATEAVAILABLEAGE helloworld-all-deployment11111sNAMEDESIREDCURRENTREADYAGE helloworld-all-deployment-7c46b4c7dc1111s localhost:~ xunyang$

4 Verify that the application is working as expected

localhost:~ xunyang$ kubectl create -f helloworld-all.yaml deployment.apps "helloworld-all-deployment" created service "helloworld-all-service" created localhost:~ xunyang$ kubectlget all NAMEREADYSTATUSRESTARTSAGE helloworld-all-deployment-7c46b4c7dc-2x7561/1Running01sNAMETYPECLUSTER-IPEXTERNAL-IPPORT(S)AGE helloworld-all-serviceLoadBalancer10.98.124.8280:30100/TCP1s kubernetesClusterIP10.96.0.1443/TCP1mNAMEDESIREDCURRENTUP-TO-DATEAVAILABLEAGE helloworld-all-deployment11111sNAMEDESIREDCURRENTREADYAGE helloworld-all-deployment-7c46b4c7dc1111s localhost:~ xunyang$ minikube service helloworld-all-service Opening kubernetes service default/helloworld-all-service in default browser...

5 Scale the helloworld application

localhost:~ xunyang$ kubectl get all NAMEREADYSTATUSRESTARTSAGE helloworld-all-deployment-7c46b4c7dc-sl9tx0/1ContainerCreating00sNAMETYPECLUSTER-IPEXTERNAL-IPPORT(S)AGE helloworld-all-serviceLoadBalancer10.110.116.8580:30265/TCP0s kubernetesClusterIP10.96.0.1443/TCP2mNAMEDESIREDCURRENTUP-TO-DATEAVAILABLEAGE helloworld-all-deployment11100sNAMEDESIREDCURRENTREADYAGE helloworld-all-deployment-7c46b4c7dc1100s localhost:~ xunyang$ kubectl scale --replicas=3 deploy/helloworld-all-deployment deployment.extensions "helloworld-all-deployment" scaled localhost:~ xunyang$ kubectl get all NAMEREADYSTATUSRESTARTSAGE helloworld-all-deployment-7c46b4c7dc-bzsgv0/1ContainerCreating00s helloworld-all-deployment-7c46b4c7dc-sl9tx1/1Running015s helloworld-all-deployment-7c46b4c7dc-vd4h70/1ContainerCreating00sNAMETYPECLUSTER-IPEXTERNAL-IPPORT(S)AGE helloworld-all-serviceLoadBalancer10.110.116.8580:30265/TCP15s kubernetesClusterIP10.96.0.1443/TCP2mNAMEDESIREDCURRENTUP-TO-DATEAVAILABLEAGE helloworld-all-deployment333115sNAMEDESIREDCURRENTREADYAGE helloworld-all-deployment-7c46b4c7dc33115s localhost:~ xunyang$ kubectl get all NAMEREADYSTATUSRESTARTSAGE helloworld-all-deployment-7c46b4c7dc-bzsgv0/1ContainerCreating03s helloworld-all-deployment-7c46b4c7dc-sl9tx1/1Running020s helloworld-all-deployment-7c46b4c7dc-vd4h71/1Running03sNAMETYPECLUSTER-IPEXTERNAL-IPPORT(S)AGE helloworld-all-serviceLoadBalancer10.110.116.8580:30265/TCP20s kubernetesClusterIP10.96.0.1443/TCP2mNAMEDESIREDCURRENTUP-TO-DATEAVAILABLEAGE helloworld-all-deployment333220sNAMEDESIREDCURRENTREADYAGE helloworld-all-deployment-7c46b4c7dc33220s localhost:~ xunyang$ kubectl get all NAMEREADYSTATUSRESTARTSAGE helloworld-all-deployment-7c46b4c7dc-bzsgv1/1Running08s helloworld-all-deployment-7c46b4c7dc-sl9tx1/1Running025s helloworld-all-deployment-7c46b4c7dc-vd4h71/1Running08sNAMETYPECLUSTER-IPEXTERNAL-IPPORT(S)AGE helloworld-all-serviceLoadBalancer10.110.116.8580:30265/TCP25s kubernetesClusterIP10.96.0.1443/TCP2mNAMEDESIREDCURRENTUP-TO-DATEAVAILABLEAGE helloworld-all-deployment333325sNAMEDESIREDCURRENTREADYAGE helloworld-all-deployment-7c46b4c7dc33325s

6 clear data

localhost:~ xunyang$ kubectl delete deployment --all deployment.extensions "helloworld-all-deployment" deleted localhost:~ xunyang$ kubectl delete services --all service "helloworld-all-service" deleted service "kubernetes" deleted localhost:~ xunyang$ kubectlget all NAMETYPECLUSTER-IPEXTERNAL-IPPORT(S)AGE kubernetesClusterIP10.96.0.1443/TCP0s