Migrating from Ranch 1.6 to 1.7

Ranch 1.7 adds built-in support for the PROXY protocol.

The PROXY protocol is a simple and efficient way for proxies to transmit information about the client.

While a third-party library already existed, it was not entirely compatible with the Ranch interface, in particular when socket active mode was involved. This new implementation fixes that and supports the full protocol with as little overhead as possible compared to normal operations: just one extra function call.

Ranch 1.7 is compatible with Erlang/OTP 19.0 onward. Support for Erlang/OTP 18 has been removed.

Features added

• Full support for the PROXY protocol was added.

New functions

• Add the function ranch:recv_proxy_header/2 to receive the PROXY protocol header and parse it. It must be called before ranch:handshake/1,2.
• Add the functions ranch_proxy_header:parse/1 and ranch_proxy_header:header/1,2 to parse and build a PROXY protocol header, respectively.

Bugs fixed

• Fix a race condition when the listener is restarted after ranch_listener_sup crashes. This resulted in the original options being used even if the options were updated at runtime.
• Make the acceptors exit instead of crash when the listening socket has been closed to prevent unnecessary logs.
• Fix an issue where listener information would not get cleaned up when an embedded listener was stopped. This was fixed in Ranch 1.6.2.