5 files changed, 43 insertions, 145 deletions
diff --git a/zones/default.nix b/zones/default.nix
index de03a0d..dc3eb9f 100644
--- a/zones/default.nix
+++ b/zones/default.nix
@@ -1,6 +1,40 @@
-{lib, ...}: {
-  "vhack.eu" = import ./vhack.eu/zone.nix {inherit lib;};
-  "j-schoeffel.de" = import ./j-schoeffel.de/zone.nix {inherit lib;};
-  "jaki-schoeffel.de" = import ./jaki-schoeffel.de/zone.nix {inherit lib;};
-  "jaki.li" = import ./jaki.li/zone.nix {inherit lib;};
+{lib, ...}: let
+  /*
+  Computes a reasonable value for the DNS serial number from the date of last change
+  and the iteration of that day.
+
+  # Type
+
+  mkSerial :: Number -> Number -> Number -> Number -> Number
+
+  # Arguments
+
+  year
+  : The year of the last change in the format YYYY.
+
+  month
+  : The month of the last change in the format MM.
+
+  day
+  : The day of the last change in the format DD.
+
+  iteration
+  : The number of change on that day. The format should be CC (assuming there are less
+    than 100 changes happening on a day) .
+
+  # Examples
+
+  mkSerial 2025 04 01 01
+  => 2025040101
+  */
+  mkSerial = year: month: day: iteration: let
+    n2 = lib.strings.fixedWidthNumber 2;
+    n4 = lib.strings.fixedWidthNumber 4;
+  in
+    lib.strings.toIntBase10 "${n4 year}${n2 month}${n2 day}${n2 iteration}";
+in {
+  "vhack.eu" = import ./vhack.eu/zone.nix {inherit mkSerial;};
+  "j-schoeffel.de" = import ./j-schoeffel.de/zone.nix {inherit mkSerial;};
+  "jaki-schoeffel.de" = import ./jaki-schoeffel.de/zone.nix {inherit mkSerial;};
+  "jaki.li" = import ./jaki.li/zone.nix {inherit mkSerial;};
 }
diff --git a/zones/j-schoeffel.de/zone.nix b/zones/j-schoeffel.de/zone.nix
index a162a92..655f937 100644
--- a/zones/j-schoeffel.de/zone.nix
+++ b/zones/j-schoeffel.de/zone.nix
@@ -1,38 +1,4 @@
-{lib, ...}: let
-  /*
-  Computes a reasonable value for the DNS serial number from the date of last change
-  and the iteration of that day.
-
-  # Type
-
-  mkSerial :: Number -> Number -> Number -> Number -> Number
-
-  # Arguments
-
-  year
-  : The year of the last change in the format YYYY.
-
-  month
-  : The month of the last change in the format MM.
-
-  day
-  : The day of the last change in the format DD.
-
-  iteration
-  : The number of change on that day. The format should be CC (assuming there are less
-    than 100 changes happening on a day) .
-
-  # Examples
-
-  mkSerial 2025 04 01 01
-  => 2025040101
-  */
-  mkSerial = year: month: day: iteration: let
-    n2 = lib.strings.fixedWidthNumber 2;
-    n4 = lib.strings.fixedWidthNumber 4;
-  in
-    lib.strings.toIntBase10 "${n4 year}${n2 month}${n2 day}${n2 iteration}";
-in {
+{mkSerial, ...}: {
   SOA = {
     nameServer = "name-server1.j-schoeffel.de.";
     adminEmail = "dns-admin@foss-syndicate.org";
diff --git a/zones/jaki-schoeffel.de/zone.nix b/zones/jaki-schoeffel.de/zone.nix
index d79f2f1..94830e0 100644
--- a/zones/jaki-schoeffel.de/zone.nix
+++ b/zones/jaki-schoeffel.de/zone.nix
@@ -1,38 +1,4 @@
-{lib, ...}: let
-  /*
-  Computes a reasonable value for the DNS serial number from the date of last change
-  and the iteration of that day.
-
-  # Type
-
-  mkSerial :: Number -> Number -> Number -> Number -> Number
-
-  # Arguments
-
-  year
-  : The year of the last change in the format YYYY.
-
-  month
-  : The month of the last change in the format MM.
-
-  day
-  : The day of the last change in the format DD.
-
-  iteration
-  : The number of change on that day. The format should be CC (assuming there are less
-    than 100 changes happening on a day) .
-
-  # Examples
-
-  mkSerial 2025 04 01 01
-  => 2025040101
-  */
-  mkSerial = year: month: day: iteration: let
-    n2 = lib.strings.fixedWidthNumber 2;
-    n4 = lib.strings.fixedWidthNumber 4;
-  in
-    lib.strings.toIntBase10 "${n4 year}${n2 month}${n2 day}${n2 iteration}";
-in {
+{mkSerial, ...}: {
   SOA = {
     nameServer = "name-server1.jaki-schoeffel.de.";
     adminEmail = "dns-admin@foss-syndicate.org";
diff --git a/zones/jaki.li/zone.nix b/zones/jaki.li/zone.nix
index 792fce2..3e55907 100644
--- a/zones/jaki.li/zone.nix
+++ b/zones/jaki.li/zone.nix
@@ -1,38 +1,4 @@
-{lib, ...}: let
-  /*
-  Computes a reasonable value for the DNS serial number from the date of last change
-  and the iteration of that day.
-
-  # Type
-
-  mkSerial :: Number -> Number -> Number -> Number -> Number
-
-  # Arguments
-
-  year
-  : The year of the last change in the format YYYY.
-
-  month
-  : The month of the last change in the format MM.
-
-  day
-  : The day of the last change in the format DD.
-
-  iteration
-  : The number of change on that day. The format should be CC (assuming there are less
-    than 100 changes happening on a day) .
-
-  # Examples
-
-  mkSerial 2025 04 01 01
-  => 2025040101
-  */
-  mkSerial = year: month: day: iteration: let
-    n2 = lib.strings.fixedWidthNumber 2;
-    n4 = lib.strings.fixedWidthNumber 4;
-  in
-    lib.strings.toIntBase10 "${n4 year}${n2 month}${n2 day}${n2 iteration}";
-in {
+{mkSerial, ...}: {
   SOA = {
     nameServer = "name-server1.jaki.li.";
     adminEmail = "dns-admin@foss-syndicate.org";
diff --git a/zones/vhack.eu/zone.nix b/zones/vhack.eu/zone.nix
index 91b5232..891d95a 100644
--- a/zones/vhack.eu/zone.nix
+++ b/zones/vhack.eu/zone.nix
@@ -1,38 +1,4 @@
-{lib, ...}: let
-  /*
-  Computes a reasonable value for the DNS serial number from the date of last change
-  and the iteration of that day.
-
-  # Type
-
-  mkSerial :: Number -> Number -> Number -> Number -> Number
-
-  # Arguments
-
-  year
-  : The year of the last change in the format YYYY.
-
-  month
-  : The month of the last change in the format MM.
-
-  day
-  : The day of the last change in the format DD.
-
-  iteration
-  : The number of change on that day. The format should be CC (assuming there are less
-    than 100 changes happening on a day) .
-
-  # Examples
-
-  mkSerial 2025 04 01 01
-  => 2025040101
-  */
-  mkSerial = year: month: day: iteration: let
-    n2 = lib.strings.fixedWidthNumber 2;
-    n4 = lib.strings.fixedWidthNumber 4;
-  in
-    lib.strings.toIntBase10 "${n4 year}${n2 month}${n2 day}${n2 iteration}";
-in {
+{mkSerial, ...}: {
   SOA = {
     nameServer = "name-server1.vhack.eu.";
     adminEmail = "dns-admin@foss-syndicate.org";