Docker is basically a virtual machine image you write your software in. Then when you run the software you don’t need to worry about compatibility or having the right dependencies installed, it’s all included in the docker image.
Think of Docker as being Nintendo cartridges that you can take to any friends house, plug them in, and play. Servers can run more than one Docker container.
The approach greatly simplifies writing code and having it work on your server, reduces errors, and adds a layer of security.
I’ve read and reread, listened and relistened to info on docker/containers and I still feel like I’m missing something tbh.
Let’s say you have a docker container for something and it’s for a Linux distro, that won’t run on another OS, will it? Maybe not even a different Linux distro from the one it was made for (e.g. Ubuntu or Arch or Fedora or whatever).
To go off your example, Docker’s not like an expansion module to make your Switch games work on a PlayStation or Xbox…Right? There seems to be some kind of mixed messaging on this, the way they’re so readily recommended (which seems to be related to a presumption of familiarity that often isn’t there toward those inquiring).
I guess I’ve also been confused because like…Shouldn’t old installers handle bundling or pulling relevant dependencies as they’re run? I’d imagine that’s where containers’ security benefits come into play though, alongside being virtualized processes if I’m not mistaken.
For simplicity its easiest to imagine it as a simulator or emulator. Its not trying to be your machine (called the host machine) pretend it doesn’t actually use your os, or software.
Imagine each container is a fresh new machine on your desk with a blank hard drive. The image is basically the result of a set of instructions (a Dockerfile) that docker follows to install all the stuff you need to get the machine running.
Normally it starts by installing an os like alpine Linux (alpine publish this docker image and you simply build on top of that)
Then you install any extra utilities and software you might need to run the programming, maybe python or Java (again there are images themselves based on alpine managed and updated by official sources)
Finally you install what you want and tell the computer that’s what to run when it boots up (often the software you want to run gives an official docker image which has done all this for you)
So when you run a docker image its actually done all this setup for you already and just stored the resultsin a way that it can apply it straight to your shiny new container in an instant and be ready.
Docker compose is instructions on how to set up a bunch of computers with a network.
What’s the difference between a docker and just installing an app on rented server space?
Functionally? Not much. But people who selfhost typically want everything on computers they own. Whether it’s for learning purposes, or to not have their stuff on “someone else’s computer” selfhosting usually means you’re running software on computers you own, almost always within your own house.
Does each dock (?) have its own server? (Apache or nginx or whatever?)
Each docker image usually has a web server built in. The philosophy of docker is that it contains everything needed to run the app. Even a small linux OS (LibELEC or Alpine are favorites for docker images). So while you’re not managing the web server in a docker image each docker image will have its own web server if web access is needed
Does each dock host a whole site, or do you have a dock for your database and a dock for your web app?
Docker the program is what runs all the docker images on a computer. Each docker image is built as per the software’s developer. Some docker images will have a web app and a database combined into a single image, while others will expect a separate database server running independent of the image (It won’t care if the database server is a docker image or not; just that it has access)
Okay. I keep reading about docker. What’s the difference between a docker and just installing an app on rented server space?
Does each dock (?) have its own server? (Apache or nginx or whatever?)
Does each dock host a whole site, or do you have a dock for your database and a dock for your web app?
Docker is basically a virtual machine image you write your software in. Then when you run the software you don’t need to worry about compatibility or having the right dependencies installed, it’s all included in the docker image.
Think of Docker as being Nintendo cartridges that you can take to any friends house, plug them in, and play. Servers can run more than one Docker container.
The approach greatly simplifies writing code and having it work on your server, reduces errors, and adds a layer of security.
I’ve read and reread, listened and relistened to info on docker/containers and I still feel like I’m missing something tbh.
Let’s say you have a docker container for something and it’s for a Linux distro, that won’t run on another OS, will it? Maybe not even a different Linux distro from the one it was made for (e.g. Ubuntu or Arch or Fedora or whatever).
To go off your example, Docker’s not like an expansion module to make your Switch games work on a PlayStation or Xbox…Right? There seems to be some kind of mixed messaging on this, the way they’re so readily recommended (which seems to be related to a presumption of familiarity that often isn’t there toward those inquiring).
I guess I’ve also been confused because like…Shouldn’t old installers handle bundling or pulling relevant dependencies as they’re run? I’d imagine that’s where containers’ security benefits come into play though, alongside being virtualized processes if I’m not mistaken.
For simplicity its easiest to imagine it as a simulator or emulator. Its not trying to be your machine (called the host machine) pretend it doesn’t actually use your os, or software.
Imagine each container is a fresh new machine on your desk with a blank hard drive. The image is basically the result of a set of instructions (a Dockerfile) that docker follows to install all the stuff you need to get the machine running.
Normally it starts by installing an os like alpine Linux (alpine publish this docker image and you simply build on top of that)
Then you install any extra utilities and software you might need to run the programming, maybe python or Java (again there are images themselves based on alpine managed and updated by official sources)
Finally you install what you want and tell the computer that’s what to run when it boots up (often the software you want to run gives an official docker image which has done all this for you)
So when you run a docker image its actually done all this setup for you already and just stored the resultsin a way that it can apply it straight to your shiny new container in an instant and be ready.
Docker compose is instructions on how to set up a bunch of computers with a network.
Functionally? Not much. But people who selfhost typically want everything on computers they own. Whether it’s for learning purposes, or to not have their stuff on “someone else’s computer” selfhosting usually means you’re running software on computers you own, almost always within your own house.
Each docker image usually has a web server built in. The philosophy of docker is that it contains everything needed to run the app. Even a small linux OS (LibELEC or Alpine are favorites for docker images). So while you’re not managing the web server in a docker image each docker image will have its own web server if web access is needed
Docker the program is what runs all the docker images on a computer. Each docker image is built as per the software’s developer. Some docker images will have a web app and a database combined into a single image, while others will expect a separate database server running independent of the image (It won’t care if the database server is a docker image or not; just that it has access)
Thanks!