fd

Package fd provides a simple API to pass file descriptors between different OS processes.

It can be useful if you want to inherit network connections from another process without closing them.

Example scenario:

• Running server receives a "let's upgrade" message
• Server opens a Unix domain socket for the "upgrade"
• Server starts a new copy of itself and passes Unix domain socket name
• New copy starts reading data from the socket
• Server sends its state over the socket, also sending the number of network connections to inherit, then it sends those connections using fd.Put()
• New server copy reads the state and inherits connections using fd.Get(), checks that everything is OK and writes an "OK" message to the socket
• Server receives "OK" message and kills itself

Documentation

fd on godoc.org