What is docker? And how is it works?

What is Docker? And How Does It Work?

Docker has become a cornerstone of modern software development, revolutionizing how applications are built, shipped, and deployed. But what exactly is Docker, and how does it work? This blog will demystify Docker and explain its role in simplifying development workflows.

What is Docker?

Docker is an open-source platform that enables developers to automate the deployment of applications inside lightweight, portable containers. These containers bundle everything an application needs to run, including code, libraries, dependencies, and runtime, ensuring consistency across different environments.

Key Features of Docker:

• Portability: Run the same container on your laptop, testing server, or production environment.
• Isolation: Containers run in isolated environments, preventing conflicts between applications.
• Efficiency: Containers share the host system's kernel, making them lightweight and faster than virtual machines.
• Scalability: Easily scale your application by spinning up multiple containers.

Install Docker using the apt repository

Before you install Docker Engine for the first time on a new host machine, you need to set up the Docker apt repository. Afterward, you can install and update Docker from the repository.

• Set up Docker's apt repository.

sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

- Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] 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

• Install the Docker packages.

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

Install Portainer CE with Docker on Linux

• Deployment

docker volume create portainer_data

• Then, download and install the Portainer Server container:

docker run -d -p 8000:8000 -p 9443:9443 --name portainer --restart=always -v /var/run/docker.sock:/var/run/docker.sock -v portainer_data:/data portainer/portainer-ce:2.21.4

Portainer Server has now been installed. You can check to see whether the Portainer Server container has started by running docker ps:

root@server:~# docker ps
CONTAINER ID   IMAGE                          COMMAND                  CREATED       STATUS      PORTS                                                                                  NAMES             
de5b28eb2fa9   portainer/portainer-ce:2.21.4  "/portainer"             2 weeks ago   Up 9 days   0.0.0.0:8000->8000/tcp, :::8000->8000/tcp, 0.0.0.0:9443->9443/tcp, :::9443->9443/tcp   portainer

Now that the installation is complete, you can log into your Portainer Server instance by opening a web browser and going to:

https://localhost:9443