cmdline: Support NILMDB_URL environment variable for default URL

nilmdb/cmdline/cmdline.py

@@ -6,6 +6,7 @@ from nilmdb.utils import datetime_tz
 import nilmdb.utils.time
 
 import sys
+import os
 import argparse
 from argparse import ArgumentDefaultsHelpFormatter as def_form
 
@@ -29,6 +30,7 @@ class Cmdline(object):
     def __init__(self, argv = None):
         self.argv = argv or sys.argv[1:]
         self.client = None
+        self.def_url = os.environ.get("NILMDB_URL", "http://localhost:12380")
 
     def arg_time(self, toparse):
         """Parse a time string argument"""
@@ -50,7 +52,7 @@ class Cmdline(object):
 
         group = self.parser.add_argument_group("Server")
         group.add_argument("-u", "--url", action="store",
-                           default="http://localhost:12380/",
+                           default=self.def_url,
                            help="NilmDB server URL (default: %(default)s)")
 
         sub = self.parser.add_subparsers(title="Commands",