Add x-openstack-request-id header for nova v3

Add the x-openstack-request-id header to nova v3 responses

bp cross-service-request-id

Change-Id: Ib3e5230e56ab280a252578d075ec174d38cfdbca

specs/juno/cross-service-request-id.rst

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+..
+ This work is licensed under a Creative Commons Attribution 3.0 Unported
+ License.
+
+ http://creativecommons.org/licenses/by/3.0/legalcode
+
+==========================================
+API v3: Add x-openstack-request-id header
+==========================================
+
+https://blueprints.launchpad.net/nova/+spec/cross-service-request-id
+
+The various OpenStack services are standardizing on a common header name to
+use for the request ID: x-openstack-request-id. Nova currently uses the header
+x-compute-request-id.
+
+Problem description
+===================
+
+nova sends the request ID as x-compute-request-id. Other services (cinder,
+glance, neutron) send x-openstack-request-id.
+
+
+Proposed change
+===============
+
+Use x-openstack-request-id when handling v3 requests for nova. There is existing
+middleware in oslo to generate the ID and attach the header to the response.
+
+Alternatives
+------------
+
+The current approach -- keeping the existing header name -- is the alternative.
+This will perpetuate header name discontinuity among OpenStack services.
+
+Another alternative is to include the new header name for both v2 and v3. But
+the benefits of doing so is not great enough to justify altering the behavior of
+the existing API.
+
+Data model impact
+-----------------
+
+None.
+
+REST API impact
+---------------
+
+This change will add a new header to HTTP responses. The new header,
+x-openstack-request-id, will have the same value as x-compute-request-id.
+After this blueprint is implemented, v2 will continue to return
+x-compute-request-id. For v3, only x-openstack-request-id will be returned.
+
+Security impact
+---------------
+
+None.
+
+Notifications impact
+--------------------
+
+None.
+
+Other end user impact
+---------------------
+
+Users making requests using the v3 API will only receive the new header,
+x-openstack-request-id. python-novaclient uses x-compute-request-id (if present)
+when reporting an HTTPError; this will need to be updated to use the new header
+name when novaclient is using v3. Other clients moving from v2 to v3 will need
+to consider the header name change.
+
+Performance Impact
+------------------
+
+None.
+
+Other deployer impact
+---------------------
+
+This change has an UpgradeImpact, since it relies on adding middleware to the
+pipeline in api-paste.ini. Since the middleware is taking over the task of
+attaching the header to the response, not updating api-paste.ini will cause
+responses to be returned without the x-openstack-request-id header.
+Additionally, when using the v2 API, the x-compute-request-id header will also
+be missing. The impact of this will be missing request ID information in
+error output by novaclient, as alluded to in a previous section.
+
+Developer impact
+----------------
+
+None.
+
+
+Implementation
+==============
+
+Assignee(s)
+-----------
+
+chris-buccella
+
+Work Items
+----------
+
+1) Sync request_id middleware from oslo (complete)
+2) Use request_id middleware to add x-openstack-request-id to both the v3
+   pipeline in api-paste.ini
+3) Write middleware to attach x-compute-request-id. Add this to the v2 pipeline
+   only.
+4) Remove existing x-compute-request-id header manipulation code from
+   api/openstack/wsgi.py
+
+
+Dependencies
+============
+
+None.
+
+
+Testing
+=======
+
+Due to the header name change, api/compute/v3/servers/test_instance_actions
+will be affected, as it references the current header name. We already have
+a skip in place for this, and will update the test to use the new name after
+this blueprint is completed.
+
+
+Documentation Impact
+====================
+
+v3 responses of the API will only include x-openstack-request-id, not
+x-compute-request-id.
+
+
+References
+==========
+
+Discussion from the HK Summit:
+https://etherpad.openstack.org/p/icehouse-summit-nova-cross-project-request-ids
+
+Refinements from the ML:
+http://lists.openstack.org/pipermail/openstack-dev/2013-December/020774.html
+
+Existing change:
+https://review.openstack.org/#/c/66903/