example

gone daemon ctrl example

Package gone/daemon/crtl creates general UNIX domain socket server which can execute commands inside the daemon process by implementing a simple Command interface.

Commands can be long-running (as outputting accesslog) and client connections to the socket will survive daemon reload and re-spawning.

This has all kinds of potential usage. Inspecting and/or manipulating state, tweaking log levels and in general instrument the daemon in ways not possible with simple OS signaling.

The program in this example shows how to use if for simple control of an HTTP server by changing Handler state and outputting access log.

Start the server like:

./example -s cmd.sock

It'll listen with HTTP on localhost:4321

You can connect to the socket with simple command line tools:

rlwrap nc -U cmd.sock

or feed it commands directly:

cat <(echo accesslog main) - | nc -U cmd.sock

The ctrl package is still somewhat experimental in terms of concept and API.