Introduction

This is to help developers to get fast a running development environment for debugging.

This Docker environment is to test/develop a Turbine app using a docker test database.

The build should take place outside the docker container.

It is based on one docker-compose.yml file and two Dockerfiles.

Docker compose uses two services: app (maven:3-jdk-8) and db (mysql:latest).

Note

  • Mysql should easily be replacable by Mariadb.
  • Instead of using maven as the app service a Jetty container might be the better choice as currently console reloading might not work.

Prepare

To run the build with maven do this outside of the container using following mvn command:

mvn clean install -Pdocker

N.B.: This builds the integrationtest project in target/test-classes/projects/first/project/integrationtest with docker enabled configuration. Running the build inside the container is not required and may be problematic, unless you use only public available dependencies.

Installation (running the app)

  • Change into the projects docker resource folder
cd docker-resources

Check Docker Compose file (optional)

  • Check services in docker-compose.yml (volumes). You might map your local maven repostory like this:
  volumes:
    - ../:/myapp
    - '<localpath>:/m2repo'
 ```yml

- Check format:

docker-compose config

- Check database service call in **src/main/webapp/WEB-INF/jetty-env.xml**. It should reference the service name (db), not localhost - as it is also set in maven docker profile.

```xml
<Set name="url">jdbc:mysql://db:3306/turbine</Set>

Cleanup or restart (optional)

  • Optionally Check system or cleanup, e.g. with docker-compose down, docker-compose down -v or docker sytem prune (removes any container on system).

Start

  • If services are already installed, activate/start by
    docker-compose up
  • Starting the app service will build the app and start jetty with Maven on port 8081. This command is set as a command in the app service in docker compose.

If not yet done, build on the host with

mvn clean install -f ../pom.xml -Pdocker

Start and Stopp the service

Start both services in one step

docker-compose up

.. or doing it in background, requires second start command

docker-compose -d up
docker-compose start

This will start first the db service, then the app service. Jetty is run exposing the webapp to http://localhost:8081/app.

Login should work with user admin/password or user/password.

By default remote debugging is activated (port 9000), which could be removed/commented in docker-compose.yml.

You could follow the logs (in folder docker-resources) with

docker-compose logs -f app

or

 docker-compose logs -f db.

Stop by Ctrl-C or

docker-compose down

Lifecycle (developers only)

  • If you generate the archetype itself, you might have to stop the services before cleaning up (docker-compose stop).

Debugging Services: Db, App

Db Service

docker-compose run --rm db /bin/sh --build-arg DB_CONTEXT=./docker-resources/db

Extract data in db service

 mysql -u root -h db -P 3306 -p

.. or

docker-compose exec db mysql -u root --password=... -e "show databases;" --build-arg DB_CONTEXT=./docker-resources/db
docker-compose exec db sh -c 'exec mysqldump --all-databases -uroot -p...' --build-arg DB_CONTEXT=./docker-resources/db > dump.sql

App Service

This will start app and db (as it depends on app):

docker-compose run --rm app /bin/sh

In the container, check:

ls -la /myapp // should list pom.xml ...

Build Services

The app service uses later a volume, which maps to the local maven repository, which you may need/not need. The db service uses mysql (currently 8.0.x), you may replace it with a fixed release tag, e.g. 5.6.

In any case, you need then to rebuild the image.

  • Build the image
    docker-compose build --no-cache

.. optionally build it separately docker-compose build --no-cache --build-arg DB_CONTEXT=./docker-resources/db db

.. building app service first/only requires removing the dependency in docker-compose.yml(comment depends_on: db) docker-compose build --no-cache app

DB_CONTEXT is set to allow starting the db container standalone (in folder db, e.g. with docker build --tag my-db .) to test it. CAVEAT: The db service is build and populated until now with hard coded data. It is a dependency for the service app (see app/Dockerfile).

System Specific Informations

Windows

Powershell

  • Use Powershell

  • Replace in volume mapping for host repo path (maven localRepository) backslashes with slashes “/” in docker-compose.yml.

  • check COMPOSE_CONVERT_WINDOWS_PATHS, https://docs.docker.com/compose/reference/envvars/#compose_convert_windows_paths

  • If a image download fails, try Docker->Network->Update DNS to 8.8.8.8

  • ERROR, when starting docker-compose up/start: “for db Cannot start service db: driver failed programming external connectivity on endpoint docker-resources_db_1 or ERROR: for docker-resources_db_1 Cannot start service db: driver failed programming external connectivity on endpoint docker-resources_db_1 ... Error starting userland proxy: mkdir /port/tcp:0.0.0.0:13306:tcp:...:3306: input/output error”

    • Check if containers not already running.
    • Remove containers (if any): docker rm $(docker ps -a -q)
    • If error still there, restart Docker Desktop on your machine.

Windows Subsystem for Linux (WSL)

More Internals, Helpful Docker commands

Resetting / Preparation (optional)

docker-compose rm -v

Delete all images

docker rmi $(docker images -q)

Still more docker commands ...

docker ps

// delete intermediate images, volumes docker rmi $(docker images --filter “dangling=true” -q) docker volume rm $(docker volume ls -qf dangling=true)

or delete while building

docker build --rm

cleans all containers

docker system prune

stops all running containers

docker stop $(docker ps -a -q)