Support for docker secrets

Author: 3vilWind

decouple.py

@@ -146,6 +146,28 @@ def __getitem__(self, key):
         return self.data[key]
 
 
+class RepositorySecret(RepositoryEmpty):
+    """
+    Retrieves option keys from files,
+    where title of file is a key, content of file is a value
+    e.g. Docker swarm secrets
+    """
+
+    def __init__(self, source='/run/secrets/'):
+        self.data = {}
+
+        ls = os.listdir(source)
+        for file in ls:
+            with open(os.path.join(source, file), 'r') as f:
+                self.data[file] = f.read()
+
+    def __contains__(self, key):
+        return key in os.environ or key in self.data
+
+    def __getitem__(self, key):
+        return self.data[key]
+
+
 class AutoConfig(object):
     """
     Autodetects the config file and type.

tests/secrets/db_password

@@ -0,0 +1 @@
+world

tests/secrets/db_user

@@ -0,0 +1 @@
+hello

tests/test_secrets.py

@@ -0,0 +1,21 @@
+# coding: utf-8
+import os
+
+from decouple import Config, RepositorySecret
+
+
+def test_secrets():
+    path = os.path.join(os.path.dirname(__file__), 'secrets')
+    config = Config(RepositorySecret(path))
+
+    assert 'hello' == config('db_user')
+    assert 'world' == config('db_password')
+
+
+def test_env_undefined_but_present_in_os_environ():
+    path = os.path.join(os.path.dirname(__file__), 'secrets')
+    config = Config(RepositorySecret(path))
+
+    os.environ['KeyOnlyEnviron'] = ''
+    assert '' == config('KeyOnlyEnviron')
+    del os.environ['KeyOnlyEnviron']