Containers

• Docker is an application-level virtualization using many individual images to build up the necessary services to support the target application.
• Docker image components:
  • Application code​
  • Runtime libraries​
  • System tools​ Docker is that an application can be packaged up with all of its dependent code and services and deployed as a single unit with the minimum of overhead.
• docker compose: allows you to specify runtime as well as build time configuration details for Docker containers using a YAML docker-compose.yml file.

How to build and run a container?

1. Create a Docker file with the following name .Dockerfile with the content:

   FROM [initializes a new build stage and sets the base image for subsequent instructions]
   RUN [execute any commands to create a new layer on top of the current image]
   CMD [sets the command to be executed when running a container from an image]
   

2. Build the container:

   docker build  -f <name>.Dockerfile -t <tag-list>
   

3. Run the container:

   docker run --rm httpie