I never understood how to use Docker, what makes it so special? I would really like to use it on my Rapsberry Pi 3 Model B+ to ease the setup process of selfhosting different things.

I’m currently running these things without Docker:

  • Mumble server with a Discord bridge and a music bot
  • Maubot, a plugin-based Matrix bot
  • FTP server
  • Two Discord Music bots

All of these things are running as systemd services in the background. Should I change this? A lot of the things I’m hosting offer Docker images.

It would also be great if someone could give me a quick-start guide for Docker. Thanks in advance!

  • hperrin@lemmy.worldEnglish
    7·
    4 months ago

    One benefit that might be overlooked here is that as long as you don’t use any Docker Volumes (and instead bind mount a local directory) and you’re using Docker Compose, you can migrate a whole service, tech stack and everything, to a new machine super easily. I just did this with a Minecraft server that outgrew the machine it was on. Just tar the whole directory, copy it to the new host, untar, and docker compose up -d.

    • AlexPewMasterOPEnglish
      1·
      4 months ago

      This docker compose up -d thing is something I don’t understand at all. What exactly does it do? A lot of README.md files from git repos include this command for Docker deployment. And another question: How can you automatically start the Docker container? Do you need a systemd service to run docker compose up -d?

      • hperrin@lemmy.worldEnglish
        2·
        4 months ago

        Docker Compose is basically designed to bring up a tech stack on one machine. So rather than having an Apache machine, a MySQL machine, and a Redis machine, you set up a Docker Compose file with all of those services. It’s easier than using individual Docker commands too. It sets up a network so they can all talk to each other, then opens the ports you tell it to. It’s isolated from other Docker Compose networks, so things won’t interfere with each other. So you can basically isolate a bunch of services with their own tech stacks all on the same machine. I’ve got my Jellyfin server running on the same machine as my Mastodon instance, thanks to Docker Compose.

        As long as Docker is configured to run automatically at boot (which it usually is when you install it), it will bring containers back up that are set to be restarted. You can use the “always” or the “unless-stopped” values for the restart option, depending on your needs, then Docker will bring that container back up after a reboot.

        Docker Compose is also useful in this context, because you can define dependencies for services. So I can say that the Mastodon container depends on the Postgres container, and Docker Compose will always start the Postgres container first.

      • Fisch@discuss.tchncs.deEnglish
        1·
        3 months ago

        You just need the docker and docker-compose packages. You make a docker-compose.yml file and there you define all settings for the container (image, ports, volumes, …). Then you run docker-compose up -d in the directory where that file is located and it will automatically create the docker container and run it with the settings you defined. If you make changes to the file and run the command again, it will update the container to use the new settings. In this command docker-compose is just the software that allows you to do all this with the docker-compose.yml file, up means it’s bringing the container up (which means starting it) and -d is for detached, so it does that in the background (it will still tell you in the terminal what it’s doing while creating the container).