How to Install Docker on Debian 9 Stretch / Debian 8
Docker is a free and open-source containerization software that helps to deploy, run applications in a container. The containers are similar to a virtual machine but consume fewer resource, easy to manage and can run anywhere regardless of operating environment it is running in.
Docker uses cgroups and namespace to allow the independent containers to run within a single Linux instance.
Note: Docker needs a 64-bit version of Debian OS and Kernel version should be at least 3.10.
Docker is now available in two editions, namely.
- Community Edition (CE)
- Enterprise Edition (EE)
Here, we will install Docker Comunity Edition (CE) from Docker repository.
Uninstall older versions of Docker called “docker” or “docker-engine“ along with associated dependencies. If your system does not have a Docker package, skip the below step.
sudo apt-get -y remove docker docker-engine docker.io
Contents such as volumes, images, and networks under /var/lib/docker/ directory are preserved.
Setup Docker Repository
Install the below packages to have “apt” get the support of https method.
sudo apt-get update sudo apt-get install -y apt-transport-https ca-certificates wget software-properties-common
Add the GPG key for Docker repository on your system.
wget https://download.docker.com/linux/debian/gpg sudo apt-key add gpg
Add the official Docker repository to the system by running below command in the terminal.
echo "deb [arch=amd64] https://download.docker.com/linux/debian $(lsb_release -cs) stable" | sudo tee -a /etc/apt/sources.list.d/docker.list
Update the apt database.
sudo apt-get update
Make sure you are installing Docker from the official repository, not from the default Debian repository.
sudo apt-cache policy docker-ce
You should see the output like below with the Docker repository details.
docker-ce: Installed: (none) Candidate: 17.06.0~ce-0~debian Version table: 17.06.0~ce-0~debian 500 500 https://download.docker.com/linux/debian stretch/stable amd64 Packages 17.03.2~ce-0~debian-stretch 500 500 https://download.docker.com/linux/debian stretch/stable amd64 Packages 17.03.1~ce-0~debian-stretch 500 500 https://download.docker.com/linux/debian stretch/stable amd64 Packages 17.03.0~ce-0~debian-stretch 500 500 https://download.docker.com/linux/debian stretch/stable amd64 Packages
Install Docker using the “apt-get” command.
sudo apt-get -y install docker-ce
Control Docker service
To start Docker, run:
sudo systemctl start docker
To stop Docker service, run:
sudo systemctl stop docker
To restart Docker service, run:
sudo systemctl restart docker
To check the status of Docker service, run:
sudo systemctl status docker
To enable Docker service to autostart on system boot, run:
sudo systemctl enable docker
Verify Docker Installation
To test the Docker installation, we will run “hello-world” container.
sudo docker run hello-world
Below output confirms that we have correctly installed Docker on Debian OS.
Unable to find image 'hello-world:latest' locally latest: Pulling from library/hello-world b04784fba78d: Pull complete Digest: sha256:f3b3b28a45160805bb16542c9531888519430e9e6d6ffc09d72261b0d26ff74f Status: Downloaded newer image for hello-world:latest Hello from Docker! This message shows that your installation appears to be working correctly.
Allow Non-root user to run Docker
By default, to run Docker commands, the user should have root privileges or equivalent privileges via sudo. Sometimes we may need to allow non-root users to run Docker containers, so follow the below steps to allow them to run containers.
Create a group “docker“, if it does not exist.
sudo groupadd docker
Add your user to docker group, replace “raj” with your username.
sudo useradd raj
Add a user to docker group.
sudo usermod -aG docker raj
Log out and log back in. You should now be able to run Docker commands without prefixing sudo.
docker run hello-world
Docker Advanced Topics: