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.

ExecuteInTransation starts a transaction around all the storage calls within the scope of the handler function.

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.

Set of error variables for handling user group errors.