Authenticate validates a JWT from the `Authorization` header.

Authorize validates that an authenticated user has at least one role from a specified list.

Cors sets the response headers needed for Cross-Origin Resource Sharing.

Errors handles errors coming out of the call chain.

Logger writes some information about the request to the logs in the format: TraceID : (200) GET /foo -> IP ADDR (latency).

Metrics updates program counters.

Panics recovers from panics and converts the panic to an error so it is reported in Metrics and handled in Errors.