Hello everyone 
A short tutorial for Gladys developers explaining how to build a test Docker image.
Prerequisites:
You need a Docker Hub account.
Step 1: Create these environment variables in GitHub Actions
Go to your Gladys fork, under the “Settings” of your repository:
Create these secrets:
DOCKERHUB_PASSWORD (This can be an API key password)
DOCKERHUB_REPO (The Docker image to push, example: `pierregilles/gladys-test`)
DOCKERHUB_USER (your DockerHub username)
Step 2: Go to the “Actions” tab => “Build Gladys dev images”
Step 3: Start a build
Click on “Run Workflow” and select the branch to build, the architecture to build, and the Docker tag that will be used!
The build takes about 4 hour if you select all platforms.
If you want to save some time and don’t need this build, remove the arm/v7 build (it’s the one taking 4 hours).
Step 4: 
That’s it! You can now share the built Docker image, which is available at:
your_username/gladys:your_tag