Reorder Python 2 Dockerfile to install dependencies together.
[mediagoblin.git] / mediagoblin / init / config.py
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e2c6436e 1# GNU MediaGoblin -- federated, autonomous media hosting
cf29e8a8 2# Copyright (C) 2011, 2012 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
2b1e0af0 17import copy
7fadc33b 18import logging
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19import os
20import pkg_resources
21
4fd487f7 22from configobj import ConfigObj, flatten_errors
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23from validate import Validator
24
25
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26_log = logging.getLogger(__name__)
27
28
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29CONFIG_SPEC_PATH = pkg_resources.resource_filename(
30 'mediagoblin', 'config_spec.ini')
31
32
2b1e0af0 33def _setup_defaults(config, config_path, extra_defaults=None):
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34 """
35 Setup DEFAULTS in a config object from an (absolute) config_path.
36 """
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37 extra_defaults = extra_defaults or {}
38
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39 config.setdefault('DEFAULT', {})
40 config['DEFAULT']['here'] = os.path.dirname(config_path)
41 config['DEFAULT']['__file__'] = config_path
11f0e2f8 42
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43 for key, value in extra_defaults.items():
44 config['DEFAULT'].setdefault(key, value)
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45
46
11f0e2f8 47def read_mediagoblin_config(config_path, config_spec_path=CONFIG_SPEC_PATH):
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48 """
49 Read a config object from config_path.
50
51 Does automatic value transformation based on the config_spec.
52 Also provides %(__file__)s and %(here)s values of this file and
53 its directory respectively similar to paste deploy.
54
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55 Also reads for [plugins] section, appends all config_spec.ini
56 files from said plugins into the general config_spec specification.
57
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58 This function doesn't itself raise any exceptions if validation
59 fails, you'll have to do something
60
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61 Args:
62 - config_path: path to the config file
11f0e2f8 63 - config_spec_path: config file that provides defaults and value types
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64 for validation / conversion. Defaults to mediagoblin/config_spec.ini
65
66 Returns:
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67 A tuple like: (config, validation_result)
68 ... where 'conf' is the parsed config object and 'validation_result'
69 is the information from the validation process.
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70 """
71 config_path = os.path.abspath(config_path)
72
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73 # PRE-READ of config file. This allows us to fetch the plugins so
74 # we can add their plugin specs to the general config_spec.
75 config = ConfigObj(
76 config_path,
11f0e2f8 77 interpolation="ConfigParser")
7fadc33b 78
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79 # temporary bootstrap, just setup here and __file__... we'll do this again
80 _setup_defaults(config, config_path)
7fadc33b 81
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82 # Now load the main config spec
83 config_spec = ConfigObj(
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84 config_spec_path,
85 encoding="UTF8", list_values=False, _inspec=True)
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86
87 # Set up extra defaults that will be pushed into the rest of the
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88 # configs. This is a combined extrapolation of defaults based on
89 mainconfig_defaults = copy.copy(config_spec.get("DEFAULT", {}))
90 mainconfig_defaults.update(config["DEFAULT"])
91
92 plugins = config.get("plugins", {}).keys()
93 plugin_configs = {}
2b1e0af0 94
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95 for plugin in plugins:
96 try:
97 plugin_config_spec_path = pkg_resources.resource_filename(
98 plugin, "config_spec.ini")
99 if not os.path.exists(plugin_config_spec_path):
100 continue
11f0e2f8 101
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102 plugin_config_spec = ConfigObj(
103 plugin_config_spec_path,
11f0e2f8 104 encoding="UTF8", list_values=False, _inspec=True)
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105 _setup_defaults(
106 plugin_config_spec, config_path, mainconfig_defaults)
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107
108 if not "plugin_spec" in plugin_config_spec:
109 continue
110
111 plugin_configs[plugin] = plugin_config_spec["plugin_spec"]
112
113 except ImportError:
114 _log.warning(
115 "When setting up config section, could not import '%s'" %
116 plugin)
11f0e2f8 117
7fadc33b 118 # append the plugin specific sections of the config spec
11f0e2f8 119 config_spec["plugins"] = plugin_configs
7fadc33b 120
2b1e0af0 121 _setup_defaults(config_spec, config_path, mainconfig_defaults)
e2c6436e 122
4fd487f7 123 config = ConfigObj(
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124 config_path,
125 configspec=config_spec,
3eadd670 126 encoding="UTF8",
11f0e2f8 127 interpolation="ConfigParser")
e2c6436e 128
2b1e0af0 129 _setup_defaults(config, config_path, mainconfig_defaults)
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130
131 # For now the validator just works with the default functions,
132 # but in the future if we want to add additional validation/configuration
133 # functions we'd add them to validator.functions here.
243c3843 134 #
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135 # See also:
136 # http://www.voidspace.org.uk/python/validate.html#adding-functions
137 validator = Validator()
138 validation_result = config.validate(validator, preserve_errors=True)
139
140 return config, validation_result
141
142
9dba44de 143REPORT_HEADER = u"""\
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144There were validation problems loading this config file:
145--------------------------------------------------------
146"""
147
148
149def generate_validation_report(config, validation_result):
150 """
151 Generate a report if necessary of problems while validating.
152
153 Returns:
154 Either a string describing for a user the problems validating
155 this config or None if there are no problems.
156 """
157 report = []
158
159 # Organize the report
160 for entry in flatten_errors(config, validation_result):
161 # each entry is a tuple
162 section_list, key, error = entry
163
164 if key is not None:
165 section_list.append(key)
166 else:
167 section_list.append(u'[missing section]')
168
169 section_string = u':'.join(section_list)
e2c6436e 170
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171 if error == False:
172 # We don't care about missing values for now.
173 continue
e2c6436e 174
4fd487f7 175 report.append(u"%s = %s" % (section_string, error))
e2c6436e 176
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177 if report:
178 return REPORT_HEADER + u"\n".join(report)
179 else:
180 return None