To build and start the screenly/balena-prometheus-exporter project, follow the steps outlined below:

Step 1: Clone the Repository

First, clone the repository to your local machine using the following command:

git clone https://github.com/screenly/balena-prometheus-exporter.git
cd balena-prometheus-exporter

Step 2: Build the Docker Image

Use Docker to build the image for the project. The command below tags the image as balena-exporter.

docker build -t balena-exporter .

Step 3: Run the Docker Container

Once the image is built, run the container. Make sure to set the BALENA_TOKEN environment variable to authenticate with the Balena API. The command below will run the container in detached mode, mapping port 8000 on your host to port 8000 in the container.

docker run -d \
--name balena-exporter \
-p 8000:8000 \
-e BALENA_TOKEN=your_balena_token_here \
balena-exporter

Optional - Set CRAWL_INTERVAL

If you wish to set a custom crawl interval, passed as an environment variable when running the container. If not specified, it defaults to 60 seconds.

-e CRAWL_INTERVAL=your_desired_interval_here

Step 4: Verify the Setup

You should now be able to verify that the exporter is running correctly by sending a request to port 8000 using curl:

curl http://localhost:8000/metrics

This command should return metrics in Prometheus format, confirming that the exporter is functioning properly.

Environment Variables

• BALENA_TOKEN: This token is required for accessing the Balena API. Make sure to set it with a valid token from your Balena account.

• CRAWL_INTERVAL (optional): Interval for crawling metrics, in seconds. The default value is set to 60 seconds.

Dependencies

The application requires the following libraries, which you can find in the requirements.txt file:

certifi==2024.7.4
charset-normalizer==3.1.0
idna==3.4
prometheus-client==0.16.0
requests==2.31.0
urllib3==1.26.18

You can review the full project structure to understand how components interact, but the primary functionality leverages requests to communicate with the Balena API and prometheus-client to expose metrics.

For more information about the project, refer to the README file located in the repository.

Source: README.md, requirements.txt