Direwolf20 FTB docker

Direwolf20_dockerfile

FROM openjdk:8-jre

# Install stuff and prep the container
RUN apt-get update && apt install apt-utils --yes
RUN apt-get upgrade --yes --allow-remove-essential
RUN apt-get clean
RUN rm -rf /var/lib/apt/lists/* 

# The server will be installed here
RUN mkdir -p /usrc/src/server/world
WORKDIR /usr/src/server

# Add user
RUN useradd -m -U minecraft

# Get the server installer and run it
RUN wget https://api.modpacks.ch/public/modpack/79/220/server/linux -O serverinstall_79_220
RUN chmod 755 serverinstall_*
RUN echo "y" | ./serverinstall_*

# Fix the EULA
RUN echo "#By changing the setting below to TRUE you are indicating your agreement to our EULA (https://account.mojang.com/documents/minecraft_eula)." > eula.txt
RUN echo "$(date)" >> eula.text
RUN echo "eula=TRUE" >> eula.txt 
RUN chown -R minecraft:minecraft /usr/src/server

# Remove the glitched eula.txt 
RUN sed -i '2,6d' /usr/src/server/start.sh

# Change user to Minecraft
USER minecraft 

# Expose minecraft port
EXPOSE 25565

# op myself
RUN echo [{"uuid": "a5093dbf-3d33-496f-8949-c841e3ddde0b", "name": "Box0fnoobs", "level": 4 }] > /usr/src/server/ops.json

# Start the server, avoid messing with the world mount because it breaks things
RUN chmod 777 -R $(ls -I world)
CMD ["/bin/bash", "/usr/src/server/start.sh"]

Run this on the host if required to resolve java.lang.RuntimeException: Unable to create the autoreloaded config which is caused by IOException: User limit of inotify watches reached.

RUN echo 16384 | tee /proc/sys/fs/inotify/max_user_watches

Here is a good starting place for your docker-compose.yaml

version: "3.3"
services:
  server:
    container_name: server
    image: server
    volumes:
      - "/home/roland/serverTest/world:/usr/src/server/world"
    ports:
      - "25565:25565"

Another common problem is an error where world/session.lock cannot be read. To solve this i copied the world file from /usr/src/server/world to my mount location and then restarted again. To do this you can use docker cp server:/usr/src/server/world world. syntax is docker cp container_name:/source/localtion dest/location