entrypoint.sh

#!/bin/bash

# Install velocity server if it doesn't exist
if [ ! -f $WORKDIR/$PROJECT*.jar ]; then
    # Downloads API docs
    # https://api.papermc.io/docs/swagger-ui/index.html?configUrl=/openapi/swagger-config#/download-controller/download
    BASE_URL="https://api.papermc.io/v2/projects/$PROJECT"
    # If the version is not set or the version is an empty string, we will use the latest version
    if [ -z "$VERSION" ]; then
        echo "No version specified, using latest version..."
        VERSION=$(curl -s $BASE_URL | jq -r '.versions[-1]')
        BUILD=$(curl -s $BASE_URL/versions/$VERSION | jq -r '.builds[-1]')
    fi

    # If the build is not set, we will use the latest build
    if [ -z "$BUILD" ]; then
        echo "No build specified, using latest build..."
        BUILD=$(curl -s $BASE_URL/versions/$VERSION | jq -r '.builds[-1]')
    fi

    VERSION_URL="$BASE_URL/versions/$VERSION/builds/$BUILD/downloads/$PROJECT-$VERSION-$BUILD.jar"

    echo "Downloading Velocity server..."
    wget $VERSION_URL -O $WORKDIR/$PROJECT-$VERSION-$BUILD.jar
fi

# We are going to create an empty log file if it doesn't exist
# so we can avoid the error message when we try to tail the log file
if [ ! -f $WORKDIR/logs/latest.log ]; then
    touch $WORKDIR/logs/latest.log
fi

# Start the server script without waiting for it to finish
# The & at the end of the line tells bash to run the command in the background
# so that it doesn't block the rest of the script from running and we can
# tail the log file while the server is starting rather than waiting for it
# to finish starting
bash $WORKDIR/scripts/start.sh &

# Wait for the log file to be created before tailing it
while [ ! -f $WORKDIR/logs/latest.log ]; do
    echo $VERSION
    sleep 1
done

# If there are no arguments, we want to keep the container running,
# so the tmux session doesn't exit
# Otherwise, we want to execute the command passed through docker
if [ $# = 0 ]; then
    tail -f $WORKDIR/logs/latest.log
else
    # execute the command passed through docker
    exec "$@"
fi