Synnefo » ./kamaki

# Copyright 2011 GRNET S.A. All rights reserved.

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import json

import logging

import os

from os.path import exists, expanduser

# Path to the file that stores the configuration

CONFIG_PATH = expanduser('~/.kamakirc')

# Name of a shell variable to bypass the CONFIG_PATH value

CONFIG_ENV = 'KAMAKI_CONFIG'

# The defaults also determine the allowed keys

CONFIG_DEFAULTS = {

    'apis': 'compute image storage cyclades pithos',

    'token': '',

    'url': '',

    'compute_token': '',

    'compute_url': 'https://okeanos.grnet.gr/api/v1',

    'image_token': '',

    'image_url': 'https://okeanos.grnet.gr/plankton',

    'storage_account': '',

    'storage_container': '',

    'storage_token': '',

    'storage_url': 'https://plus.pithos.grnet.gr/v1'

}

log = logging.getLogger('kamaki.config')

class ConfigError(Exception):

    pass

class Config(object):

    def __init__(self):

        self.path = os.environ.get(CONFIG_ENV, CONFIG_PATH)

        self.defaults = CONFIG_DEFAULTS

        d = self.read()

        for key, val in d.items():

            if key not in self.defaults:

                log.warning('Ignoring unknown config key "%s".', key)

        self.d = d

        self.overrides = {}

    def read(self):

        if not exists(self.path):

            return {}

        with open(self.path) as f:

            data = f.read()

        try:

            d = json.loads(data)

            assert isinstance(d, dict)

            return d

        except (ValueError, AssertionError):

            msg = '"%s" does not look like a kamaki config file.' % self.path

            raise ConfigError(msg)

    def write(self):

        self.read()     # Make sure we don't overwrite anything wrong

        with open(self.path, 'w') as f:

            data = json.dumps(self.d, indent=True)

            f.write(data)

    def items(self):

        for key, val in self.defaults.items():

            yield key, self.get(key)

    def get(self, key):

        if key in self.overrides:

            return self.overrides[key]

        if key in self.d:

            return self.d[key]

        return self.defaults.get(key, '')

    def set(self, key, val):

        if key not in self.defaults:

            log.warning('Ignoring unknown config key "%s".', key)

            return

        self.d[key] = val

        self.write()

    def delete(self, key):

        if key not in self.defaults:

            log.warning('Ignoring unknown config key "%s".', key)

            return

        self.d.pop(key, None)

        self.write()

    def override(self, key, val):

        assert key in self.defaults

        if val is not None:

            self.overrides[key] = val