Deployment on Google kubernetes clusters with Maven

There are two ways to do the deployment

By Installing gcloud sdk and kubectl at your local system.
By using Google cloud shell

Here I am describing the steps for method 2 (By using Google cloud shell) because you don’t need any setup for your local system.

Step 1: Crete a file with name Dockerfile in your git repository root directory with the following content

FROM maven:3.6-jdk-11 as build
#copy pom
COPY pom.xml .
#resolve maven dependencies
RUN mvn clean install -Dmaven.test.skip -Dmaven.main.skip -Dspring-boot.repackage.skip && rm -r target/
#copy source
COPY src ./src
# build the app (no dependency download here)
RUN mvn clean install -Dmaven.test.skip
#RUN mvn -f app/pom.xml  clean install package

# latest oracle openjdk is the basis
FROM openjdk:11
# copy jar file into container image under app directory
#COPY app/target/kickstart-0.0.1-SNAPSHOT.jar app/app.jar
COPY --from=build ./target/kickstart-0.0.1-SNAPSHOT.jar app/app.jar
# expose server port accept connections
EXPOSE 8080
# start application
#CMD ["java","-Dspring.profiles.active=local", "-jar", "app/app.jar"]
ENTRYPOINT ["java", "-Djava.security.egd=file:/dev/./urandom", "-jar","app/app.jar"]

FROM maven:3.6-jdk-11 as build

#copy pom

COPY pom.xml .

#resolve maven dependencies

RUN mvn clean install -Dmaven.test.skip -Dmaven.main.skip -Dspring-boot.repackage.skip && rm -r target/

#copy source

COPY src ./src

# build the app (no dependency download here)

RUN mvn clean install -Dmaven.test.skip

#RUN mvn -f app/pom.xml clean install package

# latest oracle openjdk is the basis

FROM openjdk:11

# copy jar file into container image under app directory

#COPY app/target/kickstart-0.0.1-SNAPSHOT.jar app/app.jar

COPY --from=build ./target/kickstart-0.0.1-SNAPSHOT.jar app/app.jar

# expose server port accept connections

EXPOSE 8080

# start application

#CMD ["java","-Dspring.profiles.active=local", "-jar", "app/app.jar"]

ENTRYPOINT ["java", "-Djava.security.egd=file:/dev/./urandom", "-jar","app/app.jar"]

Step 2: Open https://console.cloud.google.com and Open Cloud Shell by clicking the button in the navigation bar in the upper-right corner of the console.

At the bottom below screen will be opened

Step 3: Run the cammand with your cluster name

gcloud container clusters get-credentials <Cluster-name>

1 2	gcloud container clusters get-credentials <Cluster-name>

Step 4: Crete the docker image with git repository

sudo docker build -t <docker-image-name> <url-to-clone-repo>#<branch_name>

1 2	sudo docker build -t <docker-image-name> <url-to-clone-repo>#<branch_name>

A prompt for git password

Step 5: Push the docker image

docker push <docker-image-name>

1 2	docker push <docker-image-name>

Step 6 : create a deployment.yaml file and place the following code or copy from previous deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: guardian
spec:
  replicas: 1
  selector:
    matchLabels:
      app: guardian
  template:
    metadata:
      labels:
        app: guardian
    spec:
      containers:
        - name: app
          image: <docker-image-name>
          ports:
            - containerPort: 8080
          imagePullPolicy: Always
          readinessProbe:
            httpGet:
              path: /api/global/health  # for checking readiness
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 30
          livenessProbe:
            httpGet:
              path: /api/global/health # for checking liveness
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 30

apiVersion: apps/v1

kind: Deployment

metadata:

name: guardian

spec:

replicas: 1

selector:

matchLabels:

app: guardian

template:

metadata:

labels:

app: guardian

spec:

containers:

- name: app

image: <docker-image-name>

ports:

- containerPort: 8080

imagePullPolicy: Always

readinessProbe:

httpGet:

path: /api/global/health # for checking readiness

port: 8080

initialDelaySeconds: 5

periodSeconds: 30

livenessProbe:

httpGet:

path: /api/global/health # for checking liveness

port: 8080

initialDelaySeconds: 5

periodSeconds: 30

and apply the deployment

kubectl apply -f <path to deployment.yaml file>

1 2	kubectl apply -f <path to deployment.yaml file>

You can check deployment & pods status – scale by following cammands

kubectl get deployments
kubectl get pods
kubectl get service

kubectl get deployments

kubectl get pods

kubectl get service

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