Docker

Definition

Platform for building, running, and shipping cross-platform applications using container technology.

Image

• Container snapshot/template containing all necessary files & dependencies to run an application.

• The Docker Hub is a public registry of Docker images.

• Create a Docker image with a Dockerfile.

Image commands

Command	Description
docker images	List all images.
docker image build <dockerfile>	Build an image from a Dockerfile.
docker image rm <image>	Remove an image.
docker image tag <image> <tag>	Create an alias for an image.
docker pull <image>	Pull an image from the Docker Hub.

Container

• Running instance of an image.

Create/Run a container

docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

Option	Description
-d	Run container in background.
-it	Make container interactive through a terminal.
-p	Publish a container's port(s) to the host: hostPort:containerPort.
--rm	Automatically remove the container when it exits.
-v	Mount a volume: hostPath:containerPath.
-w	Working directory inside the container.

Volumes

• Persistent data storage for containers.

• Independent from the container's lifecycle.

• Can be shared between containers.

Data volumes

• Default Docker storage type;

• Works on both Linux and Windows;

• Easy to move/save;

• Can be used with volumes drivers for remote storage (NFS, SAMBA, cloud, ...).

Bind volumes

• Map a host directory to a container directory;

TMPFS volumes

• Stored in the host's memory;

• Faster than data volumes;

• Linux only;

• Same lifecycle as the container;

• Can't be shared between containers.