Allow to set any default configuration value from environment

issue7620
review74301002

CHANGELOG

@@ -1,3 +1,4 @@
+* Allow to set any default configuration value from environment
 * Clear existing session when password is changed
 * Manage session with max_age and timeout
 * Use passlib to hash and update password

doc/topics/configuration.rst

@@ -20,6 +20,9 @@ For more information see ConfigParser_.
 
 .. _ConfigParser: http://docs.python.org/2/library/configparser.html
 
+The default value of any option can be changed using environment variables
+with names using this syntax: `TRYTOND_<SECTION>__<NAME>`.
+
 Sections
 ========
 

trytond/config.py

@@ -77,8 +77,21 @@ class TrytonConfigParser(configparser.RawConfigParser):
         self.set('password', 'length', 8)
         self.set('password', 'entropy', 0.75)
         self.set('password', 'reset_timeout', 24 * 60 * 60)
+        self.update_environ()
         self.update_etc()
 
+    def update_environ(self):
+        for key, value in os.environ.items():
+            if not key.startswith('TRYTOND_'):
+                continue
+            try:
+                section, option = key[len('TRYTOND_'):].lower().split('__', 1)
+            except ValueError:
+                continue
+            if not self.has_section(section):
+                self.add_section(section)
+            self.set(section, option, value)
+
     def update_etc(self, configfile=os.environ.get('TRYTOND_CONFIG')):
         if isinstance(configfile, str):
             configfile = [configfile]