prepare for backends module splitting

bin/netjsonconfig

@@ -6,6 +6,7 @@ import six
 import argparse
 import netjsonconfig
 
+
 description = """
 Converts a NetJSON DeviceConfiguration object to native router configurations.
 
@@ -56,7 +57,7 @@ output = parser.add_argument_group('output')
 
 output.add_argument('--backend', '-b',
                     required=True,
-                    choices=['openwrt', 'openwisp', 'openvpn'],
+                    choices=netjsonconfig.get_backends().keys(),
                     action='store',
                     type=str,
                     help='Configuration backend')
@@ -166,13 +167,8 @@ context = dict(os.environ)
 method = args.method
 method_arguments = parse_method_arguments(args.args)
 
-backends = {
-    'openwrt': netjsonconfig.OpenWrt,
-    'openwisp': netjsonconfig.OpenWisp,
-    'openvpn': netjsonconfig.OpenVpn
-}
 
-backend_class = backends[args.backend]
+backend_class = netjsonconfig.get_backends()[args.backend]
 try:
     options = dict(templates=templates, context=context)
     if args.config:

netjsonconfig/__init__.py

@@ -1,5 +1,19 @@
+from pkg_resources import iter_entry_points
+
 from .version import VERSION, __version__, get_version  # noqa
 
 from .backends.openwrt.openwrt import OpenWrt  # noqa
 from .backends.openwisp.openwisp import OpenWisp  # noqa
 from .backends.openvpn.openvpn import OpenVpn  # noqa
+
+
+def get_backends():
+    default = {
+        'openwrt': OpenWrt,
+        'openwisp': OpenWisp,
+        'openvpn': OpenVpn,
+    }
+
+    for entry_point in iter_entry_points('netjsonconfig.backends'):
+        default.update({entry_point.name.lower(): entry_point.load()})
+    return default