Services

Services are containers that are triggered by an HTTP endpoint. Examples of services include:

• Websites
• APIs
• Webhooks

For these endpoints, we use our scale-to-zero technology to shut down unused resources and initialize them only when a request comes in.

How it Works

When you create a service, we create a public endpoint and issue a valid TLS certificate for it. By default, this endpoint hosts an empty HTTP server that you can use to test your setup.

When you provide us with a container image, we replace our static placeholder with your website or API.

Container Image Requirements

Each container image is initialized on demand, so any system deployed to DownToZero (DTZ) needs to be designed with this in mind.

By default, DTZ sets a PORT environment variable for the container and expects the instance to be launched on that port. If your application needs to run on a specific port, you can override this variable.

To check the availability of your deployed application on startup, the runtime calls the port with a HEAD / request. If the response is not an error, the load balancer marks the backend as running.

Environment Variables

The runtime provides the following environment variables to your service: