pgpool: Add derivation

pkgs/servers/sql/pgpool/default.nix

···
+{ stdenv, fetchurl, postgresql }:
+
+stdenv.mkDerivation rec {
+  name = "pgpool-II-3.4.0";
+
+  src = fetchurl {
+    url = "http://www.pgpool.net/download.php?f=${name}.tar.gz";
+    sha256 = "1aind5rbdld5ip92xlh4f6dgvdc4zxzgzi5n33xbvdrsrvagbc4j";
+  };
+
+  buildInputs = [ postgresql ];
+
+  meta = with stdenv.lib; {
+    homepage = http://pgpool.net/mediawiki/index.php;
+    description = "a middleware that works between postgresql servers and postgresql clients.";
+    license = licenses.free;
+    platforms = platforms.unix;
+    maintainers = with maintainers; [ wkennington ];
+  };
+}

pkgs/top-level/all-packages.nix

···
 
   OVMF = callPackage ../applications/virtualization/OVMF { };
 
+  pgpool92 = callPackage ../servers/sql/pgpool/default.nix {
+    postgresql = postgresql92;
+  };
+
+  pgpool93 = callPackage ../servers/sql/pgpool/default.nix {
+    postgresql = postgresql93;
+  };
+
+  pgpool = pgpool92;
+
   postgresql = postgresql92;
 
   postgresql84 = callPackage ../servers/sql/postgresql/8.4.x.nix { };