Updating deployment guide so that it can handle the current virtualenv site-packages...
[mediagoblin.git] / mediagoblin / init / config.py
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e2c6436e 1# GNU MediaGoblin -- federated, autonomous media hosting
12a100e4 2# Copyright (C) 2011 MediaGoblin contributors. See AUTHORS.
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3#
4# This program is free software: you can redistribute it and/or modify
5# it under the terms of the GNU Affero General Public License as published by
6# the Free Software Foundation, either version 3 of the License, or
7# (at your option) any later version.
8#
9# This program is distributed in the hope that it will be useful,
10# but WITHOUT ANY WARRANTY; without even the implied warranty of
11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12# GNU Affero General Public License for more details.
13#
14# You should have received a copy of the GNU Affero General Public License
15# along with this program. If not, see <http://www.gnu.org/licenses/>.
16
17import os
18import pkg_resources
19
4fd487f7 20from configobj import ConfigObj, flatten_errors
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21from validate import Validator
22
23
24CONFIG_SPEC_PATH = pkg_resources.resource_filename(
25 'mediagoblin', 'config_spec.ini')
26
27
28def _setup_defaults(config, config_path):
29 """
30 Setup DEFAULTS in a config object from an (absolute) config_path.
31 """
32 config.setdefault('DEFAULT', {})
33 config['DEFAULT']['here'] = os.path.dirname(config_path)
34 config['DEFAULT']['__file__'] = config_path
35
36
37def read_mediagoblin_config(config_path, config_spec=CONFIG_SPEC_PATH):
38 """
39 Read a config object from config_path.
40
41 Does automatic value transformation based on the config_spec.
42 Also provides %(__file__)s and %(here)s values of this file and
43 its directory respectively similar to paste deploy.
44
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45 This function doesn't itself raise any exceptions if validation
46 fails, you'll have to do something
47
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48 Args:
49 - config_path: path to the config file
50 - config_spec: config file that provides defaults and value types
51 for validation / conversion. Defaults to mediagoblin/config_spec.ini
52
53 Returns:
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54 A tuple like: (config, validation_result)
55 ... where 'conf' is the parsed config object and 'validation_result'
56 is the information from the validation process.
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57 """
58 config_path = os.path.abspath(config_path)
59
60 config_spec = ConfigObj(
e5aa1ec6 61 config_spec,
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62 encoding='UTF8', list_values=False, _inspec=True)
63
64 _setup_defaults(config_spec, config_path)
65
4fd487f7 66 config = ConfigObj(
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67 config_path,
68 configspec=config_spec,
69 interpolation='ConfigParser')
70
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71 _setup_defaults(config, config_path)
72
73 # For now the validator just works with the default functions,
74 # but in the future if we want to add additional validation/configuration
75 # functions we'd add them to validator.functions here.
243c3843 76 #
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77 # See also:
78 # http://www.voidspace.org.uk/python/validate.html#adding-functions
79 validator = Validator()
80 validation_result = config.validate(validator, preserve_errors=True)
81
82 return config, validation_result
83
84
9dba44de 85REPORT_HEADER = u"""\
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86There were validation problems loading this config file:
87--------------------------------------------------------
88"""
89
90
91def generate_validation_report(config, validation_result):
92 """
93 Generate a report if necessary of problems while validating.
94
95 Returns:
96 Either a string describing for a user the problems validating
97 this config or None if there are no problems.
98 """
99 report = []
100
101 # Organize the report
102 for entry in flatten_errors(config, validation_result):
103 # each entry is a tuple
104 section_list, key, error = entry
105
106 if key is not None:
107 section_list.append(key)
108 else:
109 section_list.append(u'[missing section]')
110
111 section_string = u':'.join(section_list)
e2c6436e 112
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113 if error == False:
114 # We don't care about missing values for now.
115 continue
e2c6436e 116
4fd487f7 117 report.append(u"%s = %s" % (section_string, error))
e2c6436e 118
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119 if report:
120 return REPORT_HEADER + u"\n".join(report)
121 else:
122 return None