JCT - JSON Configuration Tool

A JSON based Python configuration tool

Installation

pip install jct==0.0.2

Usage

Examples:

/etc/jct/default.json - First file loaded

{
    "test": {
       "more": {
            "final": {
                "value": 123
            }
       },
       "another": "another value"
    },
    "foo": "bar"
}

~/.jct/default.json - These values overwrite the above

{
    "test": {
       "more": {
            "final": {
                "value": 456
            }
       }
    },
    "boo": "far"
}

/etc/jct/test.json - These values overwrite the above

{
    "test": {
       "test_only": "test only param"
    },
    "foo": "foobar"
}

Run

JCT_ENV=test JCT__FOO="another foo" python
>>> from jct.jct import *
>>>
>>> c = create_config()
>>> print c
{u'test': {u'test_only': u'test only param', u'another': u'another value', u'more': {u'final': {u'value': 456}}}, u'foo': u'another foo', u'boo': u'far'}
>>> c.get('test.more.final.value')
123
>>> c.get('test.more.final.value.foo', 'unkown')
'unknown'

./development.json - These values overwrite the above

{
    "test": {
       "test_only": "test only param"
    },
    "foo": "foobar"
}

Run

python
>>> from jct import Jct
>>>
>>> c = Jct(env='test', default_file='development.json', config_paths=['./'], **{'a': 'b'})
>>> c
{ "a": "b", "test": { "test_only": "test only param"}, "foo": "foobar"}
>>>
>>> c == dict(c)
True
>>>
>>> c == Config(**c)
True

Run

python
>>> from jct import Config
>>>
>>> c = Config()
>>> c
{}
>>> c['x'] = {'y': 'z'}
>>> c
{'x': {'y': 'z'}}
>>> c.get('x.y')
'z'
>>> c.get('x.y.z', 'oops')
'oops'
>>> type(c)
<class 'jct.Config'>
>>> c == dict(c)
True

Configuration

By default Jct looks for JSON formatted configuration files in the following:

• /etc/jct
• ~/.jct

These can be overridden by a comma separated string in the JCT_CONFIG_PATHS environment variable

export JCT_CONFIG_PATHS=/etc/my_app/configs,/etc/my/configs

Jct will load configuration files based on the JCT_ENV environment variable. For example:

export JCT_ENV=production

By default files called default.json located in the JCT_CONFIG_PATHS are loaded. If JCT_ENV exists, it will attempt to overlay values in {JCT_ENV}.json files over the default.json values. These files MUST be valid JSON.

The default file loaded can by changed with the JCT_DEFAULT_FILE environment variable.

Configuration settings can be passed in via environment variables in the following way:

JCT__SOME__KEY_ID="some value" -> {"some": {"key_id": "some value"}}

Notice how two underscores are used to separate nested objects.

The order in which values are set for the configuration are as follows:

• Load all default.json files (from all JCT_CONFIG_PATHS in order received)
• Load all {JCT_ENV}.json files (from all JCT_CONFIG_PATHS in order received)
• Load environment variable overrides
• Override values from any passed into Class as kwargs