The redis2 module sends commands to a Redis server and answers with the
reply as it arrived, in Redis' own protocol: the body is what Redis sent,
and whatever asked for it parses that.  The module speaks the protocol
itself rather than through a library, keeps a connection for reuse, and
can send several commands in one request.

This port only installs the module sources.  The module itself is built by
the nginx ports when their REDIS2 option is enabled.