Fix #1356 -- Allow to override config file settings with env vars

src/pretix/helpers/config.py

@@ -0,0 +1,43 @@
+import os
+import re
+from configparser import _UNSET
+
+
+class EnvOrParserConfig:
+    def __init__(self, configparser):
+        self.cp = configparser
+
+    def _envkey(self, section, option):
+        section = re.sub('[^a-zA-Z0-9]', '_', section.upper())
+        option = re.sub('[^a-zA-Z0-9]', '_', option.upper())
+        return f'PRETIX_{section}_{option}'
+
+    def get(self, section, option, *, raw=False, vars=None, fallback=_UNSET):
+        if self._envkey(section, option) in os.environ:
+            return os.environ[self._envkey(section, option)]
+        return self.cp.get(section, option, raw=raw, vars=vars, fallback=fallback)
+
+    def getint(self, section, option, *, raw=False, vars=None, fallback=_UNSET):
+        if self._envkey(section, option) in os.environ:
+            return int(os.environ[self._envkey(section, option)])
+        return self.cp.getint(section, option, raw=raw, vars=vars, fallback=fallback)
+
+    def getfloat(self, section, option, *, raw=False, vars=None, fallback=_UNSET):
+        if self._envkey(section, option) in os.environ:
+            return float(os.environ[self._envkey(section, option)])
+        return self.cp.getfloat(section, option, raw=raw, vars=vars, fallback=fallback)
+
+    def getboolean(self, section, option, *, raw=False, vars=None, fallback=_UNSET):
+        if self._envkey(section, option) in os.environ:
+            return self.cp._convert_to_boolean(os.environ[self._envkey(section, option)])
+        return self.cp.getboolean(section, option, raw=raw, vars=vars, fallback=fallback)
+
+    def has_section(self, section):
+        if any(k.startswith(self._envkey(section, '')) for k in os.environ):
+            return True
+        return self.cp.has_section(section)
+
+    def has_option(self, section, option):
+        if self._envkey(section, option) in os.environ:
+            return True
+        return self.cp.has_option(section, option)