get_env(Name :: ranch:ref(), Key :: atom()) -> any() get_env(Name :: ranch:ref(), Key :: atom(), Default :: any()) -> any()
cowboy:get_env - Retrieve a listener's environment value
get_env(Name :: ranch:ref(), Key :: atom()) -> any() get_env(Name :: ranch:ref(), Key :: atom(), Default :: any()) -> any()
Retrieve an environment value for a previously started listener.
This function may crash when the key is missing from the environment and a default value is not provided.
The name of the listener to access.
The name of the listener is the first argument given to the cowboy:start_clear(3), cowboy:start_tls(3) or ranch:start_listener(3) function.
The key in the environment map. Common keys include dispatch
and middlewares
.
The default value if the key is missing.
The environment value is returned on success.
If a default was provided and the key is missing, then the default value is returned.
An exit:badarg
exception is thrown when the listener does not exist.
An exit:{badkey, Key}
exception is thrown when the key requested is missing and no default was provided.
Dispatch = cowboy:get_env(example, dispatch).
cowboy(3), cowboy:start_clear(3), cowboy:start_tls(3), cowboy:set_env(3), ranch:get_protocol_options(3)
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