Configuration Hot-Reload

The Docker Awakening Gateway supports updating its routing configuration at runtime without process restarts or dropping active connections.

How to trigger a reload

The gateway listens for the SIGHUP signal. You can trigger it via Docker:

docker kill -s HUP docker-gateway

When a SIGHUP is received:

  1. The config.yaml file is re-read from disk.
  2. A new auto-discovery pass is immediately triggered for Docker labels.
  3. The internal routing index (Host mapping) is updated safely.

What IS reloaded

The following settings are updated dynamically:

  • Static Container Mappings: Adding/removing containers under containers: in config.yaml.
  • Group Definitions: Changes to groups: and load-balancing memberships.
  • Auto-Discovery Results: Any changes to Docker labels on your containers.
  • Trusted Proxies: Changes to the trusted_proxies CIDR list for rate-limiting.

What is NOT reloaded

Certain global gateway settings are bound at startup and require a container restart to change:

Setting Reason
gateway.port The TCP socket is opened at startup. Moving it requires a process restart.
gateway.admin_auth Authentication middleware is applied to routes during initialization.
Environmental Overrides Standard process behavior; environment variables are read once at startup.

[!NOTE] If a hot-reload fails (e.g., due to a syntax error in the new config.yaml), the gateway will log an error and continue running with its previously valid configuration.

Docker Awakening Gateway — MIT License