zones: add zonefile packages for i, r, and w

krebs/3modules/zones.nix

@@ -30,6 +30,73 @@ with import <stockholm/lib>;
               all-zones;
         };
       })
+
+      # Implicit zones generated from config.krebs.hosts.*.nets.*.ip{4,6}.addr
+      (self: super: let
+        # record : { name : str, type : enum [ "A" "AAAA" ], data : str }
+
+        # toRecord : record.name -> record.type -> record.data -> record
+        toRecord = name: type: data:
+          { inherit name type data; };
+
+        # toRecords : str -> host -> [record]
+        toRecords = netname: host:
+          let
+            net = host.nets.${netname};
+          in
+          optionals
+            (hasAttr netname host.nets)
+            (filter
+              (x: x.data != null)
+              (concatLists [
+                (map
+                  (name: toRecord name "A" (net.ip4.addr or null))
+                  (concatMap
+                    (name: [ "${name}." "4.${name}." ])
+                    (net.aliases or [])))
+                (map
+                  (name: toRecord name "AAAA" (net.ip6.addr or null))
+                  (concatMap
+                    (name: [ "${name}." "6.${name}." ])
+                    (net.aliases or [])))
+              ]));
+
+        # formatRecord : record -> str
+        formatRecord = { name, type, data }: "${name} IN ${type} ${data}";
+
+        # writeZone : attrs -> package
+        writeZone =
+          { name ? "${domain}.zone"
+          , domain ? substring 0 1 netname
+          , nameservers ? [ "ni" ]
+          , netname
+          , hosts ? config.krebs.hosts
+          }:
+          self.writeText name /* bindzone */ ''
+            $TTL 60
+            @ IN SOA ns admin 1 3600 600 86400 60
+            @ IN NS ns
+            ${concatMapStringsSep "\n"
+              (name: /* bindzone */ "ns IN CNAME ${name}")
+              nameservers
+            }
+            ${concatMapStringsSep
+                "\n"
+                formatRecord
+                (concatMap
+                  (toRecords netname)
+                  (attrValues hosts))
+            }
+          '';
+      in {
+        krebs = super.krebs or {} // {
+          zones = super.krebs.zones or {} // {
+            i = writeZone { netname = "internet"; };
+            r = writeZone { netname = "retiolum"; };
+            w = writeZone { netname = "wiregrill"; };
+          };
+        };
+      })
     ];
   };