Create container images and push them to Azure Container Registry

As a next step you will need to containerize your different microservice applications. You can do so by using the below starter for containerizing a spring boot application.

You can use the below Dockerfile as a basis for your own Dockerfile.

FROM mcr.microsoft.com/openjdk/jdk:17-mariner

ARG ARTIFACT_NAME
ARG APP_PORT

EXPOSE ${APP_PORT} 8778 9779

# The application's jar file
ARG JAR_FILE=${ARTIFACT_NAME}

# Add the application's jar to the container
ADD ${JAR_FILE} app.jar

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

Step by step guidance

In the parent pom.xml file in the java-microservices-aks-lab/src directory double check the version number on line 9.

    <parent>        
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.2</version>    
    </parent>

From the Git Bash window, set a VERSION environment variable to this version number 3.0.2.
```
VERSION=3.0.2
```
You will start by building all the microservice of the spring petclinic application. To accomplish this, run mvn clean package in the root directory of the application.
```
cd ~/workspaces/java-microservices-aks-lab/src
mvn clean package -DskipTests
```

Verify that the build succeeds by reviewing the output of the mvn clean package -DskipTests command, which should have the following format:

[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary for spring-petclinic-microservices 3.0.2:
[INFO] 
[INFO] spring-petclinic-microservices ..................... SUCCESS [  0.249 s]
[INFO] spring-petclinic-admin-server ...................... SUCCESS [ 16.123 s]
[INFO] spring-petclinic-customers-service ................. SUCCESS [  6.749 s]
[INFO] spring-petclinic-vets-service ...................... SUCCESS [  4.845 s]
[INFO] spring-petclinic-visits-service .................... SUCCESS [  5.063 s]
[INFO] spring-petclinic-config-server ..................... SUCCESS [  1.777 s]
[INFO] spring-petclinic-discovery-server .................. SUCCESS [  2.563 s]
[INFO] spring-petclinic-api-gateway ....................... SUCCESS [ 15.582 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  55.901 s
[INFO] Finished at: 2023-06-02T14:07:49Z
[INFO] ------------------------------------------------------------------------

As a next step you will need to log in to your Azure Container Registry.
```
az acr login --name $MYACR
```
When your executing this lab on a local environment, make sure the docker daemon is running. If not the above statement will fail.
Create a temporary directory for creating the docker images of each microservice and navigate into this directory.
```
mkdir -p staging-acr
cd staging-acr
```

Create a Dockerfile in this new directory and add the below content.

FROM mcr.microsoft.com/openjdk/jdk:17-mariner
   
ARG ARTIFACT_NAME
ARG APP_PORT
   
EXPOSE ${APP_PORT} 8778 9779
   
# The application's jar file
ARG JAR_FILE=${ARTIFACT_NAME}
   
# Add the application's jar to the container
ADD ${JAR_FILE} app.jar
   
# Run the jar file
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]

You will reuse this Dockerfile for each microservice, each time using specific arguments.

Copy all the compiled jar files to this directory.

cp ../spring-petclinic-api-gateway/target/spring-petclinic-api-gateway-$VERSION.jar spring-petclinic-api-gateway-$VERSION.jar
cp ../spring-petclinic-admin-server/target/spring-petclinic-admin-server-$VERSION.jar spring-petclinic-admin-server-$VERSION.jar
cp ../spring-petclinic-customers-service/target/spring-petclinic-customers-service-$VERSION.jar spring-petclinic-customers-service-$VERSION.jar
cp ../spring-petclinic-visits-service/target/spring-petclinic-visits-service-$VERSION.jar spring-petclinic-visits-service-$VERSION.jar
cp ../spring-petclinic-vets-service/target/spring-petclinic-vets-service-$VERSION.jar spring-petclinic-vets-service-$VERSION.jar
cp ../spring-petclinic-config-server/target/spring-petclinic-config-server-$VERSION.jar spring-petclinic-config-server-$VERSION.jar
cp ../spring-petclinic-discovery-server/target/spring-petclinic-discovery-server-$VERSION.jar spring-petclinic-discovery-server-$VERSION.jar

Run an docker build and docker push command to build the container image for the api-gateway and push it to your Azure Container Registry.
```
docker build -t $MYACR.azurecr.io/spring-petclinic-api-gateway:$VERSION \
    --build-arg ARTIFACT_NAME=spring-petclinic-api-gateway-$VERSION.jar \
    --build-arg APP_PORT=8080 \
    .

docker image list
   
docker push $MYACR.azurecr.io/spring-petclinic-api-gateway:$VERSION
```
You are indicating here that the image should be tagged as <your-registry-name>.azurecr.io/spring-petclinic-api-gateway:3.0.2. The ARTIFACT_NAME is the jar file you want to copy into the container image which is needed to run the application. Each microservice also needs a port it will be exposed on. For the api-gateway this is port 8080.
Once this command has executed, you can check whether your image is present in your container registry.
```
az acr repository list \
   -n $MYACR
```

Now execute the same steps for the admin-server, customers-service, visits-service and vets-service.

docker build -t $MYACR.azurecr.io/spring-petclinic-admin-server:$VERSION \
    --build-arg ARTIFACT_NAME=spring-petclinic-admin-server-$VERSION.jar \
    --build-arg APP_PORT=8080 \
    .
   
docker push $MYACR.azurecr.io/spring-petclinic-admin-server:$VERSION

docker build -t $MYACR.azurecr.io/spring-petclinic-customers-service:$VERSION \
    --build-arg ARTIFACT_NAME=spring-petclinic-customers-service-$VERSION.jar \
    --build-arg APP_PORT=8080 \
    .
   
docker push $MYACR.azurecr.io/spring-petclinic-customers-service:$VERSION

docker build -t $MYACR.azurecr.io/spring-petclinic-visits-service:$VERSION \
    --build-arg ARTIFACT_NAME=spring-petclinic-visits-service-$VERSION.jar \
    --build-arg APP_PORT=8080 \
    .
   
docker push $MYACR.azurecr.io/spring-petclinic-visits-service:$VERSION

docker build -t $MYACR.azurecr.io/spring-petclinic-vets-service:$VERSION \
    --build-arg ARTIFACT_NAME=spring-petclinic-vets-service-$VERSION.jar \
    --build-arg APP_PORT=8080 \
    .
docker push $MYACR.azurecr.io/spring-petclinic-vets-service:$VERSION

Execute the same steps for the config-server, but use 8888 for the APP_PORT.

docker build -t $MYACR.azurecr.io/spring-petclinic-config-server:$VERSION \
    --build-arg ARTIFACT_NAME=spring-petclinic-config-server-$VERSION.jar \
    --build-arg APP_PORT=8888 \
    .
   
docker push $MYACR.azurecr.io/spring-petclinic-config-server:$VERSION

Execute the same steps for the discovery-server, but use 8761 for the APP_PORT.

docker build -t $MYACR.azurecr.io/spring-petclinic-discovery-server:$VERSION \
    --build-arg ARTIFACT_NAME=spring-petclinic-discovery-server-$VERSION.jar \
    --build-arg APP_PORT=8761 \
    .
   
docker push $MYACR.azurecr.io/spring-petclinic-discovery-server:$VERSION

You can now list the contents of your repository again, you should see all your container images there.

az acr repository list \
   -n $MYACR

This will output the full list of repositories you created:

 [
   "spring-petclinic-admin-server",
   "spring-petclinic-api-gateway",
   "spring-petclinic-config-server",
   "spring-petclinic-customers-service",
   "spring-petclinic-discovery-server",
   "spring-petclinic-vets-service",
   "spring-petclinic-visits-service"
 ]

You can also show all the tags in one of these repositories.

az acr repository show-tags \
    -n $MYACR \
    --repository spring-petclinic-customers-service

This will show you the version you created:

[
  "3.0.2"
]