Post install from MacPorts:

Before starting lighttpd it must be configured. Lighttpd 
is configured by editing 
/opt/local/etc/lighttpd/lighttpd.conf. There’s a sample 
config file at 
/opt/local/etc/lighttpd/lighttpd.conf.default. Please 
note that the launchd daemon relies on the PID being at 
/opt/local/var/run/lighttpd.pid.