exit: add DHCP relay for new server

Really quite shoddy as it is right now. Should get better once the old
server is retired.

roles/exit/tasks/dhcp.yml

@@ -1,16 +1,17 @@
+# TODO rewrite task and templates into something sane once the old DHCP server is retired
+- set_fact:
+    dhcp_servers: '{{ prefixes | selectattr("custom_fields.dhcp_server") | groupby(attribute="custom_fields.dhcp_server.address") }}'
+
 - name: Install keepalived
   import_tasks: keepalived.yml
 
-- name: Create keepalive notify script for systemd services
-  copy:
-    dest: /usr/local/bin/
-    src: keepalive-service
-    mode: 0755
-
-- name: Configure DHCP relays
+- name: Configure relay for old DHCP server
   template:
-    dest: "/etc/default/isc-dhcp-relay"
+    dest: '/etc/default/isc-dhcp-relay-{{ prefixes | selectattr("prefix", "==", item.0 | ipaddr("network/prefix")) | map(attribute="vrf.name") | first }}'
     src: isc-dhcp-relay.j2
+  loop: '{{ dhcp_servers }}'
+  loop_control:
+    label: "{{ item.0 }}"
   notify: restart keepalived
 
 - name: Set up keepalived