This is a trivial opaque proxy that forwards all connections to a specific host. It's designed to handle high connection volume and high traffic, and supports atomically changing the destination host and disconnecting all connections. This is potentially useful for close-to-zero-downtime failovers for certain services.
- Make sure libevent is installed.
- Build and install phosg.
- Run
make.
Run it like ./failoverproxy <listen-port> <shell-port> <dest-host> [dest-port]. If dest-port is not given, it's assumed to be the same as listen-port. The proxy will listen for new connections on listen-port, and for each one, make a connection to dest-host on dest-port and forward all data between the two endpoints bidirectionally. You can see the number of open connections and perform the atomic destination switchover by connecting to the shell port with something like nc localhost <shell-port>; in this shell, you can run help to see what the commands are.