cidr2glob: init

Based on https://gist.github.com/speshak/b62fa28b49377cda8047cb227837244c

krebs/5pkgs/simple/cidr2glob.nix

@@ -0,0 +1,30 @@
+{ python, writeScriptBin, ... }:
+
+let
+  pythonEnv = python.withPackages (ps: [ ps.netaddr ]);
+in
+  writeScriptBin "cidr2glob" ''
+    #! ${pythonEnv}/bin/python
+
+    import netaddr
+    import re
+    import sys
+
+    def cidr2glob(cidr):
+        net = netaddr.IPNetwork(cidr)
+
+        if net.prefixlen <= 8:
+            return map(lambda subnet: re.sub(r'\.0\.0\.0$', '.*', str(subnet.ip)), net.subnet(8))
+        elif net.prefixlen <= 16:
+            return map(lambda subnet: re.sub(r'\.0\.0$', '.*', str(subnet.ip)), net.subnet(16))
+        elif net.prefixlen <= 24:
+            return map(lambda subnet: re.sub(r'\.0$', '.*', str(subnet.ip)), net.subnet(24))
+        else:
+            return map(lambda ip: str(ip), list(net))
+
+    if __name__ == "__main__":
+        for cidr in sys.stdin:
+            for glob in cidr2glob(cidr):
+                print glob
+
+  ''