cool-app

This is a simple demo app that returns one of several "cool expressions" at random.

This README contains instructions for building the image and testing the app locally.

Build the image

Choose one of the following methods to build an image from the source code:

Dockerfile
Jib
Spring Boot Maven Plugin
Pack

Dockerfile

Review the Dockerfile:

cat Dockerfile

Build the image & publish to the local Docker daemon:

./mvnw package
docker build -t cool-app:1.0.0-dockerfile ./
docker images | grep cool

Optionally, publish to DockerHub (user your org name instead of the example below):

docker login # enter your username and password at the prompts
docker tag cool-app:1.0.0-dockerfile ciberkleid/cool-app:1.0.0-dockerfile
docker push ciberkleid/cool-app:1.0.0-dockerfile

Jib

Review the profiles section of the pom file to see the build configuration using jib-maven-plugin:

cat pom.xml

Build the image & publish to the local Docker daemon:

./mvnw compile jib:dockerBuild -Pjib -Dimage=cool-app:1.0.0-jib
docker images | grep cool

Alternatively, build the image & publish to DockerHub (user your org name instead of the example below):

docker login # enter your username and password at the prompts
./mvnw compile jib:build -Pjib -Dimage=ciberkleid/cool-app:1.0.0-jib

Read more about Jib and configuring the plugin in your pom file here.

Spring Boot Maven Plugin

Review the pom file to validate that Spring Boot version is 2.3.0.M1 or greater and that the default build plugin is spring-boot-maven-plugin:

cat pom.xml

Build the image & publish to the local Docker daemon:

./mvnw spring-boot:build-image
docker images | grep cool

Optionally, publish to DockerHub (user your org name instead of the example below):

docker login # enter your username and password at the prompts
docker tag cool-app:1.0.0-boot ciberkleid/cool-app:1.0.0-boot
docker push ciberkleid/cool-app:1.0.0-boot

Pack

Install the pack CLI.

Build the image & publish to the local Docker daemon:

pack build cool-app:1.0.0-pack --builder cloudfoundry/cnb:bionic
docker images | grep cool

Alternatively, build the image & publish to DockerHub (user your org name instead of the example below):

docker login # enter your username and password at the prompts
pack build ciberkleid/cool-app:1.0.0-pack --builder cloudfoundry/cnb:bionic --publish

Test the app locally

See the image(s) generated by the above approach(es) in your local Docker daemon:

docker images | grep cool

In one terminal window, start the app. Replace TAG_SUFFIX with the appropriate value as shown in the list of images returned by the previous command:

container_id=`docker run -d -p 8080:8080 cool-app:1.0.0-TAG_SUFFIX`

The docker run command returns the id of the running container, which we are storing in a variable. You can also run docker ps to see the running containers.

Send a request to the app. You should see a "cool" quote is returned.

curl http://localhost:8080; echo

Stop the app container using the container_id we captured when starting the app:

docker stop $container_id