Unable to set the metrics_callback function from the config
mohamedalikhechine opened this issue · comments
According to the Cowboy documentation, a metrics_callback function can be passed to the options when starting a new Endpoint as follows:
https://ninenines.eu/docs/en/cowboy/2.4/manual/cowboy_http2/
config :my_app, MyApp.Endpoint,
http: [port: 4000,
metrics_callback: &metrics_callback/1,
stream_handlers: [:cowboy_metrics_h, :cowboy_stream_h]]
but I get this error when I try to start it:
** (Mix) Could not start application free_license_server: MyApp.Application.start(:normal, []) returned an error: shutdown: failed to start child: MyApp.Endpoint
** (EXIT) shutdown: failed to start child: {:ranch_listener_sup, MyApp.Endpoint.HTTP}
** (EXIT) shutdown: failed to start child: :ranch_acceptors_sup
** (EXIT) :badarg
One fix was to to add :metrics_callback
to the list of protocol_options
@protocol_options [:compress, :stream_handlers, :metrics_callback]
in the Plug.Cowboy module.
I hope that this issue makes sense.
You can pass it under the :protocol_options
here: https://hexdocs.pm/plug_cowboy/Plug.Cowboy.html