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!
The most popular way of configuring containers are by using environment variables that live outside the container. But for apps that use files to store configuration, you can designate directories on your host that will be available inside the container (called “volumes” in Docker land). It’s also possible to link multiple containers together, so you can have a database container running alongside the app.
If you have all of that set up then, what benefit is there to blowing away your container and spinning up a ‘fresh’ one? I’ve never been able to wrap my head around docker, and I think this is a big part of it.
There’s a lot more to an application than its configuration. It may require certain specific system libraries, need a certain way of starting up, or a whole host of other special things. With a container, the app dev can precreate a perfect environment for their program and save you LOADS of hassle trying to set it up.
The benefit of all this is that you can know exactly where application state is stored, know that you’re running the app in it’s right environment, and it becomes turbo easy to install updates, or roll back if needed.
Totally spin up a VM, install docker on it, and deploy 2-3 web apps. You’ll notice that you use the same way of configuring them, starting and stopping them, and you might not want to look back ;)
I’ve played with it a bit. I think I was using something called DockStarter and Portainer. Like I said though, I could never quite grasp what was going on. Now for my home webapps I use Yunohost, and for my media server I use Swizzin CE. I’ve found these to be a lot easier, but I will try Docker again sometime.