Check for presence of nebula-cert and jq before starting.

[JonTheNiceGuy]

This script has two hard dependencies - nebula-cert (duh) and, less obviously, jq. jq is a way of querying JSON objects, and is used, in this context, to work out things from the Nebula CA certificate. It's also used to provide limited IP useage checks, provided all the available issued certificates are retained.

So, there should probably be some sort of command, near the top, which says (psudocode) test "$(which nebula-cert)" || error "nebula-cert is not installed"