Updated command line utility script and examples

Required by changes to implement #32
Closes #32

bin/netjsonconfig

@@ -40,16 +40,15 @@ parser.add_argument('--templates', '-t',
 parser.add_argument('--backend', '-b',
                     choices=['openwrt', 'openwisp'],
                     action='store',
-                    default='openwrt',
                     type=str,
                     help='Configuration backend: openwrt or openwisp')
 
 parser.add_argument('--method', '-m',
                     choices=['generate', 'render'],
                     action='store',
-                    default='generate',
-                    help='Backend method to use. ("generate" creates a tar.gz, "render"'
-                         'returns the entire config as a string)')
+                    help='Backend method to use. '\
+                         '"generate" returns a tar.gz archive as output; '
+                         '"render" returns the configuration in text format')
 
 parser.add_argument('--verbose',
                     action='store_true',

docs/source/general/commandline_utility.rst

@@ -8,12 +8,36 @@ languages (via system calls).
 
 Check out the available options yourself with::
 
-   netjsonconfig --help
+    $ netjsonconfig --help
+    usage: netjsonconfig [-h] [--templates [TEMPLATES [TEMPLATES ...]]]
+                         [--backend {openwrt,openwisp}]
+                         [--method {generate,render}] [--verbose] [--version]
+                         config
+
+    Converts a NetJSON DeviceConfiguration objectto working router configurations.
+
+    positional arguments:
+      config                config file or string, must be valid NetJSON
+                            DeviceConfiguration
+
+    optional arguments:
+      -h, --help            show this help message and exit
+      --templates [TEMPLATES [TEMPLATES ...]], -t [TEMPLATES [TEMPLATES ...]]
+                            list of template config files or strings separated by
+                            space
+      --backend {openwrt,openwisp}, -b {openwrt,openwisp}
+                            Configuration backend: openwrt or openwisp
+      --method {generate,render}, -m {generate,render}
+                            Backend method to use. "generate" returns a tar.gz
+                            archive as output; "render" returns the configuration
+                            in text format
+      --verbose             verbose output
+      --version, -v         show program's version number and exit
 
 Here's the common use cases explained::
 
-   # generate tar.gz from a NetJSON DeviceConfiguration object
-   netjsonconfig --backend openwrt config.json
+   # generate tar.gz from a NetJSON DeviceConfiguration object and save it to a file
+   netjsonconfig --backend openwrt --method generate config.json > config.tar.gz
 
    # see output of OpenWrt render method
    netjsonconfig --backend openwrt --method render config.json

tests/test_bin.py

@@ -11,20 +11,20 @@ class TestBin(unittest.TestCase, _TabsMixin):
     """
     def test_file_not_found(self):
         with self.assertRaises(subprocess.CalledProcessError):
-            output = subprocess.check_output("netjsonconfig WRONG", shell=True)
+            output = subprocess.check_output("netjsonconfig WRONG -b openwrt -m generate", shell=True)
 
     def test_invalid_netjson(self):
-        command = '''netjsonconfig '{ "interfaces":["w"] }' -m render'''
+        command = '''netjsonconfig '{ "interfaces":["w"] }' -b openwrt -m render'''
         with self.assertRaises(subprocess.CalledProcessError):
             output = subprocess.check_output(command, shell=True)
 
     def test_invalid_netjson_verbose(self):
-        command = '''netjsonconfig '{ "interfaces":["w"] }' -m render --verbose'''
+        command = '''netjsonconfig '{ "interfaces":["w"] }' -b openwrt -m render --verbose'''
         with self.assertRaises(subprocess.CalledProcessError):
             output = subprocess.check_output(command, shell=True)
 
     def test_empty_netjson(self):
-        output = subprocess.check_output("netjsonconfig '{}' -m render", shell=True)
+        output = subprocess.check_output("netjsonconfig '{}' -b openwrt -m render", shell=True)
         self.assertEqual(output.decode(), '')
 
     def test_templates(self):
@@ -59,15 +59,15 @@ def test_templates(self):
                 }
             ]
         })
-        command = """netjsonconfig '{0}' -m render --templates '{1}' '{2}'"""
+        command = """netjsonconfig '{0}' -b openwrt -m render --templates '{1}' '{2}'"""
         command = command.format(config, template1, template2)
         output = subprocess.check_output(command, shell=True).decode()
         self.assertIn("hostname 'template_test'", output)
         self.assertIn("interface 'eth0'", output)
         self.assertIn("interface 'wlan0'", output)
 
     def test_invalid_template(self):
-        command = "netjsonconfig '{}' -t WRONG -m render"
+        command = "netjsonconfig '{}' -b openwrt -t WRONG -m render"
         try:
             output = subprocess.check_output(command, shell=True)
         except subprocess.CalledProcessError as e: