Add context as iopipe instance attribute (#328)

Closes #327

README.md

@@ -35,6 +35,8 @@ This package provides analytics and distributed tracing for event-driven applica
   - [Chalice](https://github.com/iopipe/iopipe-python#chalice)
   - [Serverless](https://github.com/iopipe/iopipe-python#serverless)
   - [Zappa](https://github.com/iopipe/iopipe-python#zappa)
+  - [Accessing Context](https://github.com/iopipe/iopipe-python#accessing-context)
+
 - [Contributing](https://github.com/iopipe/iopipe-python#contributing)
 - [Running Tests](https://github.com/iopipe/iopipe-python#running-tests)
 - [License](https://github.com/iopipe/iopipe-python#license)
@@ -675,6 +677,20 @@ Then in your `zappa_settings.json` file include the following:
 
 Where `module-path.to.lambda_handler` is the Python module path to the `lambda_handler` you created above. For example, if you put it in `myproject/__init__.py` the path would be `myproject.lambda_handler`.
 
+### Accessing Context
+
+If the framework you're using makes it non-trivial to access the Lamba context, you can use `iopipe.context`. The `iopipe.context` is `None` if outside of an invocation.
+
+```python
+from iopipe import IOpipe
+
+iopipe = IOpipe()
+
+# Be sure to check, can be None
+if iopipe.context:
+    # do something with context
+```
+
 ## Contributing
 
 Contributions are welcome. We use the [black](https://github.com/ambv/black) code formatter.

iopipe/agent.py

@@ -48,6 +48,7 @@ def __init__(self, token=None, url=None, debug=None, plugins=None, **options):
 
         self.config = set_config(**options)
         self.config["plugins"] = self.load_plugins(self.config["plugins"])
+        self.context = None
         self.futures = []
         self.pool = futures.ThreadPoolExecutor()
         self.report = None
@@ -88,7 +89,7 @@ def __call__(self, func):
         def wrapped(event, context):
             logger.debug("%s wrapped with IOpipe decorator" % repr(func))
 
-            context = ContextWrapper(context, self)
+            self.context = context = ContextWrapper(context, self)
 
             # if env var IOPIPE_ENABLED is set to False skip reporting
             if self.config["enabled"] is False:

tests/test_agent.py

@@ -152,3 +152,16 @@ def test_disabled_reporting_with_error(
         handler(None, mock_context)
 
     assert iopipe.report.sent is False
+
+
+@mock.patch("iopipe.report.send_report", autospec=True)
+def test_context_attribute(mock_send_report, handler, mock_context):
+    """Assert that the current context is available as an iopipe attribute"""
+    iopipe, handler = handler
+
+    assert hasattr(iopipe, "context")
+    assert iopipe.context is None
+
+    handler(None, mock_context)
+
+    assert iopipe.context is not None