bundles/dhcpd: rework metadata

bundles/dhcpd/files/dhcpd.conf

@@ -1,19 +1,21 @@
-#dhcpd.conf
-
 <%
     import re
+    from ipaddress import ip_network
 %>
 ddns-update-style none;
 
 authoritative;
 
-% for identifier, subnet in dhcp_config.get('subnets', {}).items():
-# subnet '${identifier}'
-subnet ${subnet['subnet']} netmask ${subnet['netmask']} {
+% for interface, subnet in sorted(dhcp_config.get('subnets', {}).items()):
+<%
+    network = ip_network(subnet['subnet'])
+%>
+# interface ${interface} provides ${subnet['subnet']}
+subnet ${network.network_address} netmask ${network.netmask} {
 %   if subnet.get('range_lower', None) and subnet.get('range_higher', None):
     range ${subnet['range_lower']} ${subnet['range_higher']};
 %   endif
-    interface "${subnet['interface']}";
+    interface "${interface}";
     default-lease-time ${subnet.get('default-lease-time', 600)};
     max-lease-time ${subnet.get('max-lease-time', 3600)};
 %   for option, value in sorted(subnet.get('options', {}).items()):

bundles/dhcpd/files/isc-dhcp-server

@@ -14,5 +14,5 @@
 
 # On what interfaces should the DHCP server (dhcpd) serve DHCP requests?
 #	Separate multiple interfaces with spaces, e.g. "eth0 eth1".
-INTERFACESv4="${listen_interfaces}"
+INTERFACESv4="${' '.join(sorted(node.metadata.get('dhcpd/subnets', {})))}"
 INTERFACESv6=""

bundles/dhcpd/items.py

@@ -13,10 +13,6 @@ files = {
     },
     '/etc/default/isc-dhcp-server': {
         'content_type': 'mako',
-        'context': {
-            # Set by our own metadata reactor. Guaranteed to exist.
-            'listen_interfaces': node.metadata['dhcpd']['listen_interfaces'],
-        },
         'needs': {
             'pkg_apt:isc-dhcp-server'
         },

bundles/dhcpd/metadata.py

@@ -36,33 +36,18 @@ def get_static_allocations(metadata):
     }
 
 
-@metadata_reactor.provides(
-    'dhcpd/listen_interfaces',
-)
-def get_listen_interfaces(metadata):
-    listen_interfaces = []
-    for _, subnet in node.metadata.get('dhcpd/subnets', {}).items():
-        listen_interfaces.append(subnet['interface'])
-
-    return {
-        'dhcpd': {
-            'listen_interfaces': ' '.join(sorted(listen_interfaces)),
-        }
-    }
-
-
 @metadata_reactor.provides(
     'iptables/bundle_rules/dhcpd',
 )
 def iptables(metadata):
     rules = set()
-    for subnet in node.metadata.get('dhcpd/subnets', {}).values():
-        rules.add('iptables -A INPUT -i {} -p udp --dport 67:68 -j ACCEPT'.format(subnet['interface']))
+    for subnet in node.metadata.get('dhcpd/subnets', {}):
+        rules.add('iptables -A INPUT -i {} -p udp --dport 67:68 -j ACCEPT'.format(subnet))
 
     return {
         'iptables': {
             'bundle_rules': {
-                # can't use port_rules here. We're generating interface based rules here.
+                # can't use port_rules here, because we're generating interface based rules.
                 'dhcpd': sorted(list(rules)),
             },
         }

nodes/home/router.py

@@ -43,12 +43,10 @@ nodes['home.router'] = {
         },
         'dhcpd': {
             'subnets': {
-                'dmz': {
-                    'interface': 'enp1s0.23',
-                    'netmask': '255.255.255.0',
+                'enp1s0.23': {
                     'range_lower':  '172.19.139.200',
                     'range_higher': '172.19.139.250',
-                    'subnet': '172.19.139.0',
+                    'subnet': '172.19.139.0/24',
                     'options': {
                         'broadcast-address': '172.19.139.255',
                         'domain-name-servers': '172.19.139.1',
@@ -56,12 +54,10 @@ nodes['home.router'] = {
                         'subnet-mask': '255.255.255.0',
                     },
                 },
-                'home': {
-                    'interface': 'enp1s0.42',
-                    'netmask': '255.255.255.0',
+                'enp1s0.42': {
                     'range_lower':  '172.19.138.100',
                     'range_higher': '172.19.138.250',
-                    'subnet': '172.19.138.0',
+                    'subnet': '172.19.138.0/24',
                     'options': {
                         'broadcast-address': '172.19.138.255',
                         'domain-name': 'franzi-home.kunbox.net',