Added variables to command line utility #39

bin/netjsonconfig

@@ -1,5 +1,6 @@
#!/usr/bin/env python

import os
import sys
import six
import argparse
@@ -143,6 +144,7 @@ def print_output(output):
args = parser.parse_args()
config = _load(args.config)
templates = [_load(template) for template in args.templates]
context = dict(os.environ)
method = args.method
method_arguments = parse_method_arguments(args.args)

@@ -153,7 +155,7 @@ backends = {

backend_class = backends[args.backend]
try:
    instance = backend_class(config, templates=templates)
    instance = backend_class(config, templates=templates, context=context)
except TypeError as e:
    print('netjsonconfig: invalid JSON passed in config or templates')
    sys.exit(2)

docs/source/general/basics.rst

@@ -271,6 +271,8 @@ it's possible to pass multiple templates that will be added one on top of the
other to build the resulting *configuration dictionary*, allowing to reduce or
even eliminate repetitions.

.. _configuration_variables:

Context: configuration variables
--------------------------------

docs/source/general/commandline_utility.rst

@@ -67,3 +67,17 @@ Here's the common use cases explained::
Using templates::

    netjsonconfig -c config.json -t template1.json template2.json -b openwrt -m render

Environment variables
---------------------

*Environment variables* are automatically passed to the ``context`` argument (if you don't
know what this argument does please read ":ref:`configuration_variables`"), therefore
you can reference environment variables inside *configurations* and *templates*::

    export HOSTNAME=freedom
    netjsonconfig -c '{"general": { "hostname": "${HOSTNAME}" }}' -b openwrt -m render

You can also avoid using ``export`` and write everything in a one line command::

    PORT=2009; netjsonconfig -c config.json -t template1.json -b openwrt -m render

tests/test_bin.py

@@ -121,3 +121,10 @@ def test_generate_redirection(self):
        tar = tarfile.open('test.tar.gz', 'r')
        self.assertEqual(len(tar.getmembers()), 1)
        tar.close()

    def test_context(self):
        config = json.dumps({'general': {'description': '${DESC}'}})
        command = "export DESC=testdesc; netjsonconfig --config '{0}' -b openwrt -m render".format(config)
        output = subprocess.check_output(command, shell=True).decode()
        self.assertNotIn('${DESC}', output)
        self.assertIn('testdesc', output)