get-vpn-config.nix

# A function that accepts a path to a grid.nix-style file and returns a set
# with two attributes:
#
#  * serverIP - a string giving the VPN IP address of the grid's VPN server.
#
#  * clientIPs - a list of strings giving the VPN IP addresses of all of the
#                grid's VPN clients.
#
{ pathToGrid }:
let
  grid = import pathToGrid;
  vpnConfig = node: node.services.private-storage.monitoring.vpn or null;
  vpnClientIP = node: (vpnConfig node).client.ip or null;
  vpnServerIP = node: (vpnConfig node).server.ip or null;
in
{
 "serverIP" = vpnServerIP grid.monitoring;
 "clientIPs" = builtins.filter (x: x != null) (map vpnClientIP (builtins.attrValues grid));
}