Update keys() to be able to iterate over a dict by updating the loop …

instrumentation/opentelemetry-instrumentation-asgi/src/opentelemetry/instrumentation/asgi/__init__.py

@@ -260,7 +260,60 @@ def get(
         return decoded
 
     def keys(self, carrier: dict) -> typing.List[str]:
-        return [_key.decode("utf8") for (_key, _value) in carrier]
+
+        """
+        In most examples of propogators, they attempt to get a header key with .get() but when that fails they seem to 
+        want to search all keys within carrier.  There is not a prescribed structure for carrier in the specs 
+        https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/context/api-propagators.md
+        So we need to evaluate the carrier and peer into any child lists or dicts within carrier and return all of the keys
+        """
+
+
+        #define the  default empty list
+        returnable = []
+
+        #internal function that appends keys
+        def append_keys(key):
+            if isinstance(key, bytes):
+                    returnable.append(key.decode("utf8"))
+            elif isinstance(key, str):
+                    returnable.append(key)            
+
+        #carrier is a dict, so iterate over .items()
+        for _key, _val in carrier.items():
+
+            #if we have another dict, lets make a recursive call
+            if isinstance(_val, Dict):
+                #append our current key
+                append_keys(_key)
+
+                #append all keys within the dict
+                for x in self.keys(_val):
+                    append_keys(x)
+
+            # if we have a list, lets iter over that. List can contain tuples(headers) dicts and string so lets approach them all as well
+            elif isinstance(_val, List):
+                for list_key in _val:
+
+                    #Check for the Tuple
+                    if isinstance(list_key, Tuple):
+                        append_keys(list_key[0])
+
+                    #check for the dict   
+                    elif isinstance(list_key, Dict):
+                        append_keys(_key)
+
+                        #append all keys within the dict
+                        for x in self.keys(_val):
+                            append_keys(x)
+                    else:
+                        append_keys(list_key)
+
+            #finally, if our key was just a string, append that
+            else:
+                append_keys(_key) 
+
+        return returnable
 
 
 asgi_getter = ASGIGetter()

instrumentation/opentelemetry-instrumentation-asgi/tests/test_getter.py

@@ -48,3 +48,28 @@ def test_keys(self):
         getter = ASGIGetter()
         keys = getter.keys({})
         self.assertEqual(keys, [])
+
+    def test_populated_keys(self):
+        getter = ASGIGetter()
+        header = {
+            "type": "http.response.start",
+            "status": 200,
+            "headers": [
+                (b"Content-Type", b"text/plain"),
+                (b"custom-test-header-1", b"test-header-value-1"),
+                (b"custom-test-header-2", b"test-header-value-2"),
+                (
+                    b"my-custom-regex-header-1",
+                    b"my-custom-regex-value-1,my-custom-regex-value-2",
+                ),
+                (
+                    b"My-Custom-Regex-Header-2",
+                    b"my-custom-regex-value-3,my-custom-regex-value-4",
+                ),
+                (b"my-secret-header", b"my-secret-value"),
+            ],
+            }
+
+        expected_val = ['type','status','Content-Type', 'custom-test-header-1', 'custom-test-header-2', 'my-custom-regex-header-1', 'My-Custom-Regex-Header-2', 'my-secret-header']
+        keys = getter.keys(header)
+        self.assertEqual(keys, expected_val)