docker in linux ubuntu server

I’ve used Docker multiple times in the past and I wasn’t very clear on how it worked.

The program’s image (drawing) is:

I have macOS and I’m connected to a Linux Ubuntu server via SSH

I wanted to install a video game server on a Linux Ubuntu server

The installation was done directly on the OS

The installation was giving me a long error log

I didn’t know if the errors were software (OS) or hardware (architecture, PC, the physical part)

It was due to compatibility issues

Docker allows you to download and run images (an image is the installation) (public and private) of the program, OS, and hardware (there are 3 layers) (each layer is a different image). You can get public images in various places, including Docker itself (the repository)

Installing a program on a specific OS and architecture using Docker eliminates compatibility issues, as the entire environment is identical to the one used by the developers and works seamlessly.

With Docker you can emulate program + DE + hardware; it’s all together and called an environment

the environment is isolated

With Docker you can create containers, environments go inside, and you can have several containers with completely different environments

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I want to reinstall the video game server on Linux Ubuntu Server, but this time I’ll do it using Docker

In Docker I need to install 3 images: the program (game server), the Linux Ubuntu Server OS version, and the hardware or architecture that is compatible with Ubuntu Server

The program must be compatible with the OS version and the hardware

Has anyone already tested that the program works with these two images

Since someone has already tested it, there won’t be any compatibility issues

So, Docker is for doing Web 2.0 installations

Once you understand how Docker works, you’ll want to do all your installations with Docker

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Docker is very useful in a work team

Let’s assume there are 5 people in a work team

Each of the 5 people has different hardware (PC, notebook, mac)

If out of the 4 people, 2 have the same OS (macOS, Windows, Linux), they have different versions (xp, 7, vista) or distributions (ubuntu, opensuse, debian) (in the case of Linux)

Together they work with Git and upload the source code (not the executable) to a repository like GitHub or GitLab

The code will run on a Linux Ubuntu server, and the hardware will run on a server

(meaning the executable will not run on any of the 5 computers but on the server)

So each computer has to use the server to run tests? NO

Each computer uses Docker to emulate the server exactly as it is (OS and hardware)

Perhaps each computer cannot even run an executable of the source code it is programming

Not directly on your computer, but indirectly and with Docker

Each computer will need 3 images: the application, OS, and the hardware

You can get the OS and hardware images from the official Docker repository

The application image must be created by each programmer

You need to create a container in Docker and put the 3 images in it

It’s like having a jar (container) and putting 3 ingredients in it (3 images, app, OS and hardware)

This will create the same environment on 5 different computers

The application works the same on all 5 computers and will fail at the same points (you can find the same error in the same way on all 5 computers)

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install docker on ubuntu server

sudo apt-get update

sudo apt-get install ca-certificates curl gnupg

sudo install -m 0755 -d /etc/apt/keyrings

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg

sudo chmod a+r /etc/apt/keyrings/docker.gpg

echo   "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \

 $(. /etc/os-release && echo "$VERSION_CODENAME") stable" |   sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

sudo apt-get update

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

sudo usermod -aG docker $USER

docker compose version

docker run hello-world

newgrp docker

The command above is a temporary “patch” to apply group permissions in the current session without logging out. It’s fine to use it for a quick “hello-world” test, but for the change to take effect across all your processes and the server, you’ll need to log out and log back in (exit and log back in)