mulberry

Mulberry

A bare-bones TCP proxy for dynamic connection routing

What does it do?

Mulberry listens on zero or more sockets, and any incoming connections are forwarded to the endpoint specified for that listen socket.

Mulberry responds to SIGHUP by re-reading its configuration and applying it, without disrupting any existing connections whose parameters have not changed.

What is it good for?

Mulberry is useful for building High-Availability (HA) systems*. (*Some assembly required.)

The basic idea is:

• Run mulberry
• Run a daemon which monitors the health of your backends
• When the healthiest backend changes, have that daemon write an updated Mulberry config to disk and send SIGHUP to the running instance of mulberry

For advanced users:

• Generate a GPG keypair with gpg --homedir /path/to/keyring --gen-key
• Run mulberry -config /some/writable/path/config.yaml -keyring /path/to/keyring/pubring.gpg
• Monitor your backends
• When the healthiest backend changes, run mulberrypush -config /path/to/new/config.yaml -url http://hostname:8643/upload -keyring secring.gpg -keyid fingerprint; repeat for each host with a running mulberry instance