Add Docker secrets support in config (#6250)

* Add Docker secrets support in config

* ruff format

* Remove gracefully fallback exception handling

* Add support for loading secret fallbacks from environment file

src/pretix/helpers/config.py

@@ -29,36 +29,61 @@ class EnvOrParserConfig:
         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}'
+        section = re.sub("[^a-zA-Z0-9]", "_", section.upper())
+        option = re.sub("[^a-zA-Z0-9]", "_", option.upper())
+        return f"PRETIX_{section}_{option}"
+
+    def _file_envkey(self, section, option):
+        section = re.sub("[^a-zA-Z0-9]", "_", section.upper())
+        option = re.sub("[^a-zA-Z0-9]", "_", option.upper())
+        return f"FILE__PRETIX_{section}_{option}"
 
     def get(self, section, option, *, raw=False, vars=None, fallback=_UNSET):
+        if self._file_envkey(section, option) in os.environ:
+            with open(os.environ[self._file_envkey(section, option)], "r") as f:
+                return f.read().strip()
         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._file_envkey(section, option) in os.environ:
+            with open(os.environ[self._file_envkey(section, option)], "r") as f:
+                return int(f.read().strip())
         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._file_envkey(section, option) in os.environ:
+            with open(os.environ[self._file_envkey(section, option)], "r") as f:
+                return float(f.read().strip())
         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._file_envkey(section, option) in os.environ:
+            with open(os.environ[self._file_envkey(section, option)], "r") as f:
+                return self.cp._convert_to_boolean(f.read().strip())
         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)
+            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):
+        if any(k.startswith(self._file_envkey(section, "")) for k in os.environ):
+            return True
+        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._file_envkey(section, option) in os.environ:
+            return True
         if self._envkey(section, option) in os.environ:
             return True
         return self.cp.has_option(section, option)

src/pretix/settings.py

@@ -100,6 +100,11 @@ SECRET_KEY_FALLBACKS = []
 for i in range(10):
     if config.has_option('django', f'secret_fallback{i}'):
         SECRET_KEY_FALLBACKS.append(config.get('django', f'secret_fallback{i}'))
+fallback_secret_file_key = config._file_envkey('django', 'secret_fallbacks')  # FILE__PRETIX_DJANGO_SECRET_FALLBACKS
+if fallback_secret_file_key in os.environ and os.path.exists(os.environ[fallback_secret_file_key]):
+    with open(os.environ[fallback_secret_file_key], 'r') as f:
+        for line in f:
+            SECRET_KEY_FALLBACKS.append(line.strip())
 
 
 # Adjustable settings