Set global_request_id if passed in as X-OpenStack-Request-ID.

If an inbound header that validates against the regex ``req-$uuid`` is
passed in, we'll set it where oslo.context could later read it. This
creates a mechanism for parents to pass their request-id to children.

Change-Id: I5c5268e8680392395fbe04efe0124575ad8db468

3 files changed, 65 insertions, 0 deletions

diff --git a/oslo_middleware/request_id.py b/oslo_middleware/request_id.py
index 5716c82..9003fa5 100644
--- a/oslo_middleware/request_id.py
+++ b/oslo_middleware/request_id.py
@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import re
+
 from oslo_context import context
 import webob.dec
 
@@ -20,7 +22,11 @@ from oslo_middleware import base
 
 
 ENV_REQUEST_ID = 'openstack.request_id'
+GLOBAL_REQ_ID = 'openstack.global_request_id'
 HTTP_RESP_HEADER_REQUEST_ID = 'x-openstack-request-id'
+INBOUND_HEADER = 'X-Openstack-Request-Id'
+ID_FORMAT = (r'^req-[a-f0-9]{8}-[a-f0-9]{4}-'
+             r'[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$')
 
 
 class RequestId(base.ConfigurableMiddleware):
@@ -35,8 +41,18 @@ class RequestId(base.ConfigurableMiddleware):
     # oslo.middleware without impacting existing users.
     compat_headers = []
 
+    def set_global_req_id(self, req):
+        gr_id = req.headers.get(INBOUND_HEADER, "")
+        if re.match(ID_FORMAT, gr_id):
+            req.environ[GLOBAL_REQ_ID] = gr_id
+        # TODO(sdague): it would be nice to warn if we dropped a bogus
+        # request_id, but the infrastructure for doing that isn't yet
+        # setup at this stage.
+
     @webob.dec.wsgify
     def __call__(self, req):
+        self.set_global_req_id(req)
+
         req_id = context.generate_request_id()
         req.environ[ENV_REQUEST_ID] = req_id
         response = req.get_response(self.application)
diff --git a/oslo_middleware/tests/test_request_id.py b/oslo_middleware/tests/test_request_id.py
index 5c79c21..5374fa2 100644
--- a/oslo_middleware/tests/test_request_id.py
+++ b/oslo_middleware/tests/test_request_id.py
@@ -13,6 +13,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import uuid
 
 from oslotest import base as test_base
 from testtools import matchers
@@ -63,3 +64,43 @@ class RequestIdTest(test_base.BaseTestCase):
 
         self.assertEqual(res.headers.get("x-compute-req-id"), res_req_id)
         self.assertEqual(res.headers.get("x-silly-id"), res_req_id)
+
+    def test_global_request_id_set(self):
+        """Test that global request_id is set."""
+        @webob.dec.wsgify
+        def application(req):
+            return req.environ[request_id.GLOBAL_REQ_ID]
+
+        global_req = "req-%s" % uuid.uuid4()
+        app = request_id.RequestId(application)
+        req = webob.Request.blank(
+            '/test',
+            headers={"X-OpenStack-Request-ID": global_req})
+        res = req.get_response(app)
+        res_req_id = res.headers.get(request_id.HTTP_RESP_HEADER_REQUEST_ID)
+        if isinstance(res_req_id, bytes):
+            res_req_id = res_req_id.decode('utf-8')
+        # global-request-id in request environ is returned as response body
+        self.assertEqual(res.body.decode('utf-8'), global_req)
+        self.assertNotEqual(res.body.decode('utf-8'), res_req_id)
+
+    def test_global_request_id_drop(self):
+        """Test that bad format ids are dropped.
+
+        This ensures that badly formatted ids are dropped entirely.
+        """
+        @webob.dec.wsgify
+        def application(req):
+            return req.environ.get(request_id.GLOBAL_REQ_ID)
+
+        global_req = "req-%s-bad" % uuid.uuid4()
+        app = request_id.RequestId(application)
+        req = webob.Request.blank(
+            '/test',
+            headers={"X-OpenStack-Request-ID": global_req})
+        res = req.get_response(app)
+        res_req_id = res.headers.get(request_id.HTTP_RESP_HEADER_REQUEST_ID)
+        if isinstance(res_req_id, bytes):
+            res_req_id = res_req_id.decode('utf-8')
+        # global-request-id in request environ is returned as response body
+        self.assertEqual(res.body.decode('utf-8'), '')
diff --git a/releasenotes/notes/global_request_id-a8ec7260fbd76444.yaml b/releasenotes/notes/global_request_id-a8ec7260fbd76444.yaml
new file mode 100644
index 0000000..335a76d
--- /dev/null
+++ b/releasenotes/notes/global_request_id-a8ec7260fbd76444.yaml
@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    This adds support for ``global_request_id`` to the ``RequestId``
+    middleware. An inbound header of ``X-OpenStack-Request-ID`` is
+    accepted as long as it is of the format ``req-$uuid``, and made
+    available to oslo.context. This will allow for cross project
+    request id tracking.