{ pkgs, lib, ... }:
{
  name = "keepalived";
  meta.maintainers = [ lib.maintainers.raitobezarius ];

  nodes = {
    node1 =
      { pkgs, ... }:
      {
        services.keepalived.enable = true;
        services.keepalived.openFirewall = true;
        services.keepalived.vrrpInstances.test = {
          interface = "eth1";
          state = "MASTER";
          priority = 50;
          virtualIps = [ { addr = "192.168.1.200"; } ];
          virtualRouterId = 1;
        };
        environment.systemPackages = [ pkgs.tcpdump ];
      };
    node2 =
      { pkgs, ... }:
      {
        services.keepalived.enable = true;
        services.keepalived.openFirewall = true;
        services.keepalived.vrrpInstances.test = {
          interface = "eth1";
          state = "MASTER";
          priority = 100;
          virtualIps = [ { addr = "192.168.1.200"; } ];
          virtualRouterId = 1;
        };
        environment.systemPackages = [ pkgs.tcpdump ];
      };
  };

  testScript = ''
    # wait for boot time delay to pass
    for node in [node1, node2]:
        node.wait_until_succeeds(
            "systemctl show -p LastTriggerUSecMonotonic keepalived-boot-delay.timer | grep -vq 'LastTriggerUSecMonotonic=0'"
        )
        node.wait_for_unit("keepalived")
    node2.wait_until_succeeds("ip addr show dev eth1 | grep -q 192.168.1.200")
    node1.fail("ip addr show dev eth1 | grep -q 192.168.1.200")
    node1.succeed("ping -c1 192.168.1.200")
  '';
}
