Docker:
Docker is a technology that allows you to build, run, test, and deploy distributed applications. It uses operating-system-level virtualization to deliver software in packages called containers.
The way Docker does this is by packaging an application and its dependencies in a virtual container that can run on any computer. This containerization allows for much better portability and efficiency when compared to virtual machines.
These containers are isolated from each other and bundle their own tools, libraries, and configuration files. They can communicate with each other through well-defined channels. All containers are run by a single operating system kernel, and therefore use few resources.
Docker CLI tools Installation:
- update and install the following libraries
sudo apt update && \
sudo apt-get install \
ca-certificates \
curl \
gnupg \
lsb-release
- add official GPG key for docker
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
- Install Docker
sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli [containerd.io](http://containerd.io/)
For Some systems, you can install docker by
sudo apt install docker.io
- Fixes during images pull down using docker
Error:
$ sudo docker pull hello-world
Using default tag: latest
Error response from daemon: Get "https://registry-1.docker.io/v2/": proxyconnect tcp: dial tcp 192.168.0.112:3128: connect: connection refused
Fix: sudo vim /etc/systemd/system/docker.service.d/http-proxy.conf
[Service]
ENV HTTP_PROXY="http://192.168.1.112:3128"
#add the device ip
Use Docker without sudo
solution:
sudo usermod -aG docker $USER
Add user to docker group
sudo groupadd docker
sudo gpasswd -a \$USER docker
docker run hello-world