======
Docker
======

Oh my! 💀 Docker, Images, Containers
====================================

Let's talk these.

When someone talks about *Docker*, they usually mean *containers* in general.
It is quite likely that they have not used anything else but the `docker` command or *Docker Desktop*.
That is absolutely OK.
Let's clarify some vocabulary:

- **Container** — that's the thing runs anything you like, a webserver, a database server, an email server, …
- **Container Image** — this is what you need to create a container.
  You can't think of it like a cookiecutter.
  You can as many cookie as you like, it will always be the same as long as you use the same image
- **`Dockerfile`** — this is what you use to create an image.
  You do **not** have to use a *`Dockerfile`*, there are a few options.
  Another option is a general *containerfile*.
  Systems like podman use a containerfile, it is — usually — compatible with a `Dockerfile`.

How does this look?

.. todo::FIXME: enable mermaid

.. code-block:: text

  %%{ init: { 'flowchart': { 'curve': 'monotoneX' } } }%%
  graph LR

  dockerfile[/Dockerfile/]
  containerfile[/Containerfile/]

  podman_build[podman]
  docker_build[docker]

  image(Image)
  container[/Container/]


  subgraph build
    direction LR
    docker_build
    podman_build
  end

  containerfile-->podman_build
  dockerfile-->podman_build
  dockerfile-->docker_build

  subgraph runtime
  container
  end

  podman_build & docker_build-->image-->container

Prepare your environment
========================

.. todo:: Add a section about installing other tools

    - Rancher Desktop

Docker
------

- **Running a container from an existing image**

- `docker run`
- `docker run --volume ...`
- `docker run --volume ... --port ...`
- `docker run --volume ... --port ... --entrypoint`

- **Building a container from an existing image**

- `docker build ...`
- `docker buildx ...`