pkgs: add unbound-zones-adblock

Unbound wants a configuration file that is not actually formatted like
StevenBlack's hosts files. This derivation fixes that.

pkgs/default.nix

@@ -1,5 +1,5 @@
 { pkgs }:
-{
+rec {
   havm = pkgs.callPackage ./havm { };
 
   lohr = pkgs.callPackage ./lohr { };
@@ -8,5 +8,9 @@
 
   podgrab = pkgs.callPackage ./podgrab { };
 
+  unbound-zones-adblock = pkgs.callPackage ./unbound-zones-adblock {
+    inherit unified-hosts-lists;
+  };
+
   unified-hosts-lists = pkgs.callPackage ./unified-hosts-lists { };
 }

pkgs/unbound-zones-adblock/default.nix

@@ -0,0 +1,37 @@
+{ fetchFromGitHub, gawk, lib, stdenvNoCC, unified-hosts-lists }:
+stdenvNoCC.mkDerivation rec {
+  name = "unbound-zones-adblock";
+  version = unified-hosts-lists.version;
+
+  src = unified-hosts-lists;
+
+  phases = [ "installPhase" ];
+
+  installPhase =
+    let
+      gawkCmd = lib.concatStringsSep " " [
+        ''${gawk}/bin/awk''
+        '''{sub(/\r$/,"")}''
+        ''{sub(/^127\.0\.0\.1/,"0.0.0.0")}''
+        ''BEGIN { OFS = "" }''
+        ''NF == 2 && $1 == "0.0.0.0" { print "local-zone: \"", $2, "\" static"}' ''
+      ];
+    in
+    ''
+      mkdir -p $out
+      for file in $src/*; do
+          ${gawkCmd} $file | tr '[:upper:]' '[:lower:]' | sort -u > $out/$(basename $file)
+      done
+    '';
+
+  meta = with lib; {
+    description = "Unified host lists, ready to be used by unbound";
+    longDescription = ''
+      This is a simple derivation based on StevenBlack's unified hosts list.
+      The files have been modified for easy use wih unbound.
+    '';
+    homepage = "https://github.com/StevenBlack/hosts";
+    license = licenses.mit;
+    platforms = platforms.all;
+  };
+}