- Edit nomad_login and set the username and password.

- Copy nomad_login to /usr/local/bin:

$ sudo install -m 0700 nomad_login /usr/local/bin

- Add this to /System/Library/SystemConfiguration/Kicker.bundle/Contents/Resources/Kicker.xml 

        <dict>
                <key>execCommand</key>
                <string>/usr/local/bin/nomad_login</string>
                <key>execUID</key>
                <integer>0</integer>
                <key>keys</key>
                <array>
                        <string>State:/Network/Global/IPv4</string>
                </array>
                <key>name</key>
                <string>nomad_login</string>
        </dict>

- Restart configd:

$ sudo killall configd; sudo configd