Anatomy of Docker
Docker comprises several components:
- Command-line utility – Docker
- Host
- Objects
- Registries
The Docker CLI tool – docker – is the main means of managing containers and images. It is used to build images, pull them from the registry, upload them to the registry, run containers, interact with them, set runtime options, and, finally, destroy them. It is a command-line tool that communicates with Docker hosts using an API. By default, it is assumed that the docker command is being invoked on the host, but it is not strictly necessary. One docker CLI tool can manage more than one host.
The host is more interesting. The host runs dockerd – a daemon responsible for actually performing the actions ordered via the docker tool. It is here that container images are stored. The host also provides resources such as networking, storage, and the containers themselves.
The dockerd daemon is the beating heart of the containers...
