Docker - what use is it?

multicolorKnight , 3 months ago

Two things, one you care about and one you might not. The one you care about: you can set up a service in isolation. You can then test it, make sure it works, and switch over to it once you are sure, with almost no downtime. This is important for things you actually need to use. Once you do something like breaking your primary email server, you will understand. Also, less important, you can set up a service on, say, a VM at home, and move it to a VPS, without having to transfer the entire image, and it will work the same.
The one you don't care about. That last bit about moving servers around is important for cloud providers who turn these things on and off all the time.

StrawberryPigtails , 3 months ago

For me the advantage of Docker is that a random update to my system is unlikely to crash my self hosted services. It simplifies setting up the services as well but the biggest advantage is that it is generally more stable.

umbrella , 3 months ago (edited 3 months ago)

its a container system that saves you from dealing with interactions between server software, config files scattered everywhere and is even more secure and more portable.

it helps you use 1 server for many services without issues, being able to redeploy a given service without issues whenever needed.

its a bit counter intuitive to learn, but makes it plain easier and almost maintenance free to run a server if you set up things right.

rentar42 , 3 months ago

https://lemmy.world/post/12995686 was a recent question and most of the answers will basically be duplicates of that.

One slight addition I want to add: "Docker" is just one implementation of "OCI containers". It's the one that broke through initially in the hype, but you can just as easily use any other (podman being a popular one) and basically all of the benefits that people ascribe to "docker" can be applied to.

So you might (as I do) have some dislike for docker (the product) and still enjoy running containers.

Gooey0210 , 3 months ago

1. When you're prohibited from using nixos
2. When there's no package for it in nixos, and you're lazy to package it yourself

xlash123 , 3 months ago

In simple terms, it's like a VM for an application. You set it up with the right dependencies and your application will "just work" on it, without having to deal with other applications existing alongside it.

What makes it better than a VM is that it is much faster. It interfaces with kernel features that help isolate the processes and files from the rest of the system. It is not virtualization, rather it is namespacing.

Docker also provides a bunch of tools that help with creating this environment automatically and allowing for some escaping into the host, such as binding ports and sharing data with the host's file system.

Once this environment is created, it can be shared with uses as a single downloadable bundle, called an image. This makes it really easy to download and run an application without having to prepare your system with the right dependencies and files.

Nothing is free though, and the cost here is more disk space and some performance overhead, although it is close to native speed.