A custom Docker image for NATS to support automatic clustering on Fly.io.
When we detect that the image is running on Fly.io, we automatically configure clustering to use Fly's internal DNS. Each server advertises using it's allocation ID to ensure that the cluster is stable across restarts. Routes are determined by looking up the top 3 closest servers, exlcuding the current server.
NATS JetStream can be enabled by setting the NATS_JETSTREAM environment variable to any value other than 0.