Docker

Docker is a set of platform as a service (PaaS) products that use OS-level virtualization to deliver software in packages called containers.

Setup

Install docker edge release on your Linux machine.

curl -sSL https://get.docker.com/ | sh

store.docker.com has instruction for each distro if you want to install docker on a production environment.

Add your user to docker group

sudo usermod -aG docker <user-username>

Install docker-machine and docker-compose

• Follow the official documentation to install docker machine

• Follow the official documentation to install docker compose

Image vs. Container

• An image is the application we want to run - the binaries, libraries and the source code that all make up your application - packaged

• A container is a running instance of that image

• We can have many containers running off the same image

• registries are the image repositories. Docker's default image registry is at Docker Hub

Example usage to run nginx container

docker container run --publish 80:80 nginx

The above command did the following things

• Downloaded the image 'nginx' from Docker hub (as the image was not available locally)

• Started a new container from that image

• Opened port 80 on the host IP and started routing all host port 80 traffic to the container IP, port 80

The following command will do all the above things, but it will do it in the background.

docker container run --publish 80:80 --detatch nginx

Use the following command to list the containers

docker container ls

the above command only lists the currently running containers. use ls -a to get a list of all the containers

Use the following command to stop a container (which is running in the background)

docker container stop <container id>

And the following command will show the logs from a container

docker container logs <container name>