Docker Cheatsheet

Notes from the things I'm working on at the moment.

Docker Cheatsheet

Simple Dockerfile

Here is a simple Dockerfile that I used to have a test app up and running:

FROM python:3.11.0a3-alpine3.15
LABEL author "David Daniel <>"

EXPOSE 8888/tcp

RUN mkdir -p /mnt/s3data
RUN mkdir -p /data
RUN ln -s /mnt/s3data /data/input
WORKDIR /data/input
CMD python -m http.server 8888

Build a Docker Container

Assuming the name of the container is davydany/my-docker-container, and your current directory has a Dockerfile, set it up like so:

docker build -t davydany/my-docker-container .

This builds the docker image and stores the built image in your local file system.

Push a Docker Container to Remote Repository

Now that your docker container has been built locally, we want to deploy the image to a remote docker image repository. Let’s assume the hostname is and the organization/username is davydany, and the image is my-docker-container, then run this command:

docker push

Run a Built Image

Now that you have a built image locally, let’s run it by running the following command:

docker run <image-name>

If you want this image to run in the background (daemonized), run:

docker run -d <image-name>

Attach to a Running Container

To attach to a running container, run docker ps to get the container ID of the container you want to attach to, and then run:

docker exec -it <CONTAINER_ID> /bin/sh

This will open up a shell instance for you

Deploying to Gitlab

First Time

The first time you’re using Gitlab’s Docker Container Registry, you need to have your local docker cli login to it.

Since this is your first time, you will need to tell docker CLI tool to sign into Gitlab’s Container Registry.

First, let’s get your Personal Access Token:

  1. Visit:
  2. For Name:, give your personal access token a name, like docker-cli
  3. For Expires at:, leave it empty
  4. Under scopes, click on all the values: api, read_registry, write_registry.
  5. Click on Create Personal Access Token.
  6. Copy the token value and Save this value.

Now, we need to find your Gitlab Username:

  1. Visit:
  2. On the top right, click on your Avatar.
  3. Now, click on your name
  4. You will be redirected to a new page. Here, look for your username, which starts with a @, and typically has LastName.FirstName.RandomDigits. For me, it is @aeroxis

Now, let’s setup your docker cli to point to Gitlab’s Docker Container Registry.

  1. Open your terminal, and type in docker login
  2. For Username, Enter your username without the @ prefix. For me, this would be aeroxis.
  3. Press [ENTER] key.
  4. For Password, Enter the Personal Access Token that Gitlab generated for you.
  5. Press [ENTER] key.