docker-minecraft-server/DEVELOPMENT.md

Adding a server type

Adding a new server TYPE can vary due to the complexity of obtaining and configuring each type; however, the addition of any server type includes at least the following steps:

1. Copy an existing "start-deploy*" script, such as start-deployMohist and rename it accordingly making sure to retain the "start-deploy" prefix
2. Modify the type-specific behavior between the "start-utils" preamble and the hand-off to start-setupWorld at the end of the script
3. Develop and test the changes using the iterative process described below
4. Add a case-entry to the case "${TYPE^^}" in start-configuration
5. Add a section to the README. It is recommended to copy-modify an existing section to retain a similar wording and level of detail
6. Submit a pull request

Iterative script development

Individual scripts can be iteratively developed, debugged, and tested using the following procedure.

First, build a baseline of the image to include the packages needed by existing or new scripts:

PowerShell: (Example of building and testing ForgeAPI)

$env:MODS_FORGEAPI_KEY='$2a$...'
$env:FOLDER_TO_TEST="forgeapimods_projectids"
$env:IMAGE_TO_TEST="mc-dev"
docker build -t $env:IMAGE_TO_TEST .
pushd "tests/setuponlytests/$env:FOLDER_TO_TEST/"
docker-compose run mc
docker-compose down -v --remove-orphans
popd

PowerShell: Building different images of Java for testing

$env:BASE_IMAGE='eclipse-temurin:8u312-b07-jre'
$env:IMAGE_TO_TEST="mc-dev"
docker build --build-arg BASE_IMAGE=$env:BASE_IMAGE -t $env:IMAGE_TO_TEST .

Bash: (Example of building and testing ForgeAPI)

export MODS_FORGEAPI_KEY='$2a$...'
export FOLDER_TO_TEST="forgeapimods_file"
export IMAGE_TO_TEST="mc-dev"
docker build -t $IMAGE_TO_TEST .
pushd tests/setuponlytests/$FOLDER_TO_TEST/
docker-compose run mc
docker-compose down -v --remove-orphans
popd

Using the baseline image, an interactive container can be started to iteratively run the scripts to be developed. By attaching the current workspace directory, you can use the local editor of your choice to iteratively modify scripts while using the container to run them.

docker run -it --rm -v ${PWD}:/scripts -e SCRIPTS=/scripts/ --entrypoint bash mc-dev

From within the container you can run individual scripts via the attached /scripts/ path; however, be sure to set any environment variables expected by the scripts by either exporting them manually:

export VANILLA_VERSION=1.12.2
/scripts/start-magma

...or pre-pending script execution:

VANILLA_VERSION=1.12.2 /scripts/start-magma

NOTE: You may want to temporarily add an exit statement near the end of your script to isolate execution to just the script you're developing.

Using development copy of mc-image-helper

In the cloned copy of mc-image-helper, create an up-to-date snapshot build of the tgz distribution using:

./gradlew distTar

Assuming http-server is installed globally, start a static web server using:

http-server ./build/distributions -p 8080

Note the port that was selected by http-server and pass the build arguments, such as:

--build-arg MC_HELPER_VERSION=1.8.1-SNAPSHOT \
--build-arg MC_HELPER_BASE_URL=http://host.docker.internal:8080

Now the image can be built like normal, and it will install mc-image-helper from the locally built copy.

Generating release notes

The following git command can be used to provide the bulk of release notes content:

git log --invert-grep --grep "^ci:" --grep "^misc:" --grep "^docs:" --pretty="* %s" 1.1.0..1.2.0