added jinja template formatting

mwaaas · mwaaas · commit 89de186df1ae · 2018-02-23T13:30:22.000+03:00
diff --git a/dotenv/main.py b/dotenv/main.py
@@ -8,6 +8,8 @@
 import re
 from collections import OrderedDict
 
+from jinja2 import Template
+
 __escape_decoder = codecs.getdecoder('unicode_escape')
 __posix_variable = re.compile('\$\{[^\}]*\}')
 
@@ -16,6 +18,13 @@ def decode_escaped(escaped):
     return __escape_decoder(escaped)[0]
 
 
+def jinja_templating(variable):
+    if "{{" in variable:
+        template = Template(variable)
+        return template.render(**os.environ)
+    return variable
+
+
 def load_dotenv(dotenv_path, verbose=False, override=False):
     """
     Read a .env file and load into os.environ.
@@ -25,6 +34,7 @@ def load_dotenv(dotenv_path, verbose=False, override=False):
             warnings.warn("Not loading %s - it doesn't exist." % dotenv_path)
         return None
     for k, v in dotenv_values(dotenv_path).items():
+        v = jinja_templating(v)
         if override:
             os.environ[k] = v
         else:
diff --git a/requirements.txt b/requirements.txt
@@ -6,3 +6,4 @@ wheel
 pytest-cov
 click
 ipython
+Jinja2==2.7
diff --git a/setup.py b/setup.py
@@ -21,6 +21,7 @@
     packages=['dotenv'],
     install_requires=[
         'click>=5.0',
+        'Jinja2==2.7',
     ],
     entry_points='''
         [console_scripts]
diff --git a/tests/test_core.py b/tests/test_core.py
@@ -87,6 +87,36 @@ def test_load_dotenv_override(cli):
         sh.rm(dotenv_path)
 
 
+def test_load_dotenv_variable_jinja_formatting(cli):
+    dotenv_path = '.test_load_dotenv_variable_formatting'
+
+    with cli.isolated_filesystem():
+        sh.touch(dotenv_path)
+        set_key(dotenv_path, 'a', 'foo')
+        set_key(dotenv_path, 'b', '{{a}}/bar')
+        set_key(dotenv_path, 'c', '{bar}')
+        success = load_dotenv(dotenv_path)
+        assert success
+        assert os.environ['a'] == 'foo'
+        assert os.environ['b'] == 'foo/bar'
+        assert os.environ['c'] == '{bar}'
+        sh.rm(dotenv_path)
+
+
+def test_load_dotenv_variable_filtering(cli):
+    dotenv_path = '.test_load_dotenv_variable_formatting'
+    with cli.isolated_filesystem():
+        sh.touch(dotenv_path)
+        set_key(dotenv_path, 'd', 'foo')
+        set_key(dotenv_path, 'e', '{{a|upper}}')
+        success = load_dotenv(dotenv_path)
+        assert success
+        assert os.environ['d'] == 'foo'
+        assert os.environ['e'] == os.environ['a'].upper()
+        sh.rm(dotenv_path)
+
+
+
 def test_ipython():
     tmpdir = os.path.realpath(tempfile.mkdtemp())
     os.chdir(tmpdir)
