Build docker containers interactively with Google Cloud Shell

As of this writing, Docker Desktop is not approved for use on NCI laptops. If you want to build and push docker containers using the docker CLI, you can use the Google Cloud Shell: https://console.cloud.google.com/

You can create an account with your @nih.gov email. Certain aspects of Google Cloud cost money, but the free tier offers more than enough usage for building containers with the Google Cloud Shell.

After logging into Google Cloud Console, click the “Active Cloud Shell” button near the top right corner.

Cloud Shell has a Terminal to run commands.

Cloud Shell has an editor that’s a lot like VS Code.

Create a Dockerfile

For this tutorial, we’ll create a minimal Dockerfile with these contents:

FROM python:3.11

RUN mkdir -p /data2/
RUN echo 'hello world' > /data2/file.txt

Upload

If you already have a Dockerfile written, you can upload it to Cloud Shell.

In the file explorer tab, right-click and select “Upload”.

Write

Create a new text file:

Click File > New Text File and write the contents of your Dockerfile.

Save it with the name “Dockerfile”.

Build the container

docker build -t minimal:v1 -f ./Dockerfile .

• -t, --tag - Name and optional tag (format: “name:tag”)
• -f, --file - Name of the Dockerfile (default: “PATH/Dockerfile”)

Run docker build --help for more options.

The build completed successfully.

Test the container image

Run the container interactively with the bash shell:

docker run -it minimal:v1 bash

Run any commands you wish inside the container to test that everything you need was installed correctly.

cat /data2/file.txt
which python
python --version

This container should have python installed and should have the “hello world” file.

Close the container with the keyboard shortcut Control-DControl-D or type exit and press enter.

If the container doesn’t have the software you expected, something went wrong during the build process. Try editing the Dockerfile and re-building the container.

Push the container to dockerhub

If your container was built successfully, you can push it to a container registry such as dockerhub so you can pull it for use on other platforms.

Log in to dockerhub

docker login

Open your web browser and type in the confirmation code. This step goes very smoothly if you’re already logged in to dockerhub in your web browser.

If it worked, you’ll see “Login Succeeded” in the Terminal.

Tag & push the container image

Add a tag to the image with your username or the namespace on dockerhub (e.g. nciccbr) that you want to push the container to.

Change NAMESPACE in the following command to your username or namespace.

docker image tag minimal:v1 NAMESPACE/minimal:v1

Push the container image to dockerhub:

docker push NAMESPACE/minimal:v1

In these examples, the namespace is kellysovacool (my username)

If the push succeeded, you’ll see it in your list of repositories on dockerhub

On the repository page, you can see the list of tags that have been pushed and optionally add a description, category, overview, etc.

Pull any public container

You can pull any public container from dockerhub (including the one you just pushed).

Here is the base image that we use for building most other CCBR containers. You can see details about it on dockerhub:

<https://hub.docker.com/repository/docker/nciccbr/ccbr_ubuntu_22.04/general>

CCBR base image overview with list of installed tools

Here’s an example of pulling this container from the CCBR dockerhub account:

docker pull nciccbr/ccbr_ubuntu_22.04:v4

The namespace is nciccbr, the container name is ccbr_ubuntu_22.04, and the version tag is v4.

Run the container interactively:

docker run -it nciccbr/ccbr_ubuntu_22.04:v4 bash

Docker Docs

View the Docker getting started tutorial for more detailed information: https://docs.docker.com/get-started/introduction/build-and-push-first-image/