Docker

Docker is kinda like Git. A really solid core concept with just enough surface inconsistencies to be annoying but not enough for a better solution to take the crown.

David Ellis

Docker is a system for running virtual machines called containers.

Advantages of Docker

• provides consistent, contained environment on your local machine
• containers are lightweight, portable, and boot fast
• useful for hardware agnostic software development
• can be used for non-interactive application execution

Comparison to Traditional VMs

• docker containers are stateless, container storage is erased when the container stops (mapping drives can resolve this)
• uses OS-level virtualisation, so containers share the host OS without needing a Hypervisor
• smaller and faster than VM
• docker platform can run many containers simultaneously and they can communicate with each other
• docker registries allows straightforward deployment of docker images

Architecture

• Client - CLI interface
• Daemon - background service that listend for API requests and manages docker objects
• Docker desktop - manager for other components
• Docker registry - a package repo, docker hub is the default
• Docker objects
• image is a read only template for container
• container is a runnable instance of an image

Running

docker run \
--mount type=bind,source=HOST_PATH,target=CONTAINER_PATH \
-it IMAGE:TAG

• mount sets an folder on host to folder in container
• use absolute folders
• it allows interaction
• TAG is the version of the image