Set up redundant DHCP

Wow that was actually really easy. Love broadcast protocols

playbooks/pis.yml

@@ -51,4 +51,36 @@
     - role: netplan-static-ip
       tags: [ pis, mp, dhcp, static-ip ]
     - role: dhcp
+      vars:
+        dhcp_global_failover_peer: failover-group
+        dhcp_global_failover:
+          role: primary
+          address: 192.168.103.100
+          port: 647
+          peer_address: 192.168.103.101
+          peer_port: 647
+          max_response_delay: 15
+          max_unacked_updates: 10
+          load_balance_max_seconds: 5
+          split: 255
+          mclt: 3600
+      tags: [ pis, mp, dhcp ]
+- hosts: pi-mp-2.desu.ltd
+  vars_files:
+    - vars/desulocal-dhcp.yml
+  roles:
+    - role: netplan-static-ip
+      tags: [ pis, mp, dhcp, static-ip ]
+    - role: dhcp
+      vars:
+        dhcp_global_failover_peer: failover-group
+        dhcp_global_failover:
+          role: secondary
+          address: 192.168.103.101
+          port: 647
+          peer_address: 192.168.103.100
+          peer_port: 647
+          max_response_delay: 15
+          max_unacked_updates: 10
+          load_balance_max_seconds: 5
       tags: [ pis, mp, dhcp ]

playbooks/vars/desulocal-dhcp.yml

@@ -15,6 +15,7 @@ dhcp_subnets:
       - range_begin: 192.168.1.2
         range_end: 192.168.1.254
         routers: 192.168.1.1
+        failover_peer: failover-group
 dhcp_hosts:
   # 1       Catch-all guest subnet
   - { name: router-nighthawk-1,   mac: '10:0C:6B:5A:D9:40', ip: 192.168.1.1     }