In order to support cross project request_id tracking, we need to be
on oslo.middleware for request_id. This makes that change now that
oslo middleware can support compat headers.

api-ref is not updated yet because x-compute-request-id was apparently
never documented there, and the timing on landing this is narrow
because the moment a requirements update happens we'll have this new
behavior.

Part of bp:oslo-middleware-request-id

Change-Id: I4d9f91b01de12cd0a676fc649953f98473b6b416

This patch cleans up 'v3' in the comments, by replacing 'v3' with 'v2.1'.

Co-Authored-By: Ed Leafe <ed@leafe.com>
Partial-Bug: #1462901
Change-Id: Ia665115e4c8c94b8d7557060201469ea10673558

openstack.common.context is currently moved out of the incubator
to a standalone project, hence replace it with oslo_context in nova.

Change-Id: I6cbf5d719f33072a5a871c250760512a439a7daf
Closes-Bug: #1210261

The oslo team is recommending everyone to switch to the
non-namespaced versions of libraries. Updating the hacking
rule to include a check to prevent oslo.* import from
creeping back in.

This commit includes:
- using oslo_utils instead of oslo.utils
- using oslo_serialization instead of oslo.serialization
- using oslo_db instead of oslo.db
- using oslo_i18n instead of oslo.i18n
- using oslo_middleware instead of oslo.middleware
- using oslo_config instead of oslo.config
- using oslo_messaging instead of "from oslo import messaging"
- using oslo_vmware instead of oslo.vmware

Change-Id: I3e2eb147b321ce3e928817b62abcb7d023c5f13f

Remove outdated code and replace its usages by usages of oslo.middleware
library

Sync latest request_id middleware from oslo-incubator(only to allow
grenade jobs pass)

4ffc4c8 Add middleware.request_id shim for Kilo
4504e4f Remove middleware

Co-Authored-By: Abhishek Chanda <abhishek@cloudscaling.com>
Co-Authored-By: Davanum Srinivas <dims@linux.vnet.ibm.com>

Change-Id: I89ef3df1b8d3b2c6e391d04e89e35f2ee974a3cc

This is breaking the Juno -> master grenade path. As we are using the old
api-paste.ini file which requires the oslo-incubator copy of request_id

This breakage didn't happen from Icehouse -> master since the icehouse
api-paste.ini didn't have request_id as a middleware. request_id is only
used as middleware in the V21/V3 API and not the V2 API.

Closes-Bug: #1383757
This reverts commit 641de5666f38532252e91735a1cd2611d96c489a.

Change-Id: I1ca6bddf9d9370529e999efcc7eae60622e19e6f

It has graduated to oslo-middleware

DocImpact

Change-Id: I6dbf77ee56b8008ed286e1b7c367a8a94f005498

x-openstack-request-id is the common header name for request ID going
forward. Nova, cinder, and neutron return this header. Using the
request_id middleware is a convenient way to ensure this header is in
the response. We will also be using the middleware to generate the
request ID.

The ID will be generated by the middleware and is inserted into the
request environment. The current code generates the request ID in the
constructor of RequestContext; with this change, the ID is generated
beforehand and passed in to the RequestContext constructor. Not much
different here: a request ID is generated and is available for use in
the handling of the request.

On the response end, the middleware is again used, this time to
attach the x-openstack-request-id header, using the value of the
generated request ID.

For v3, we will be using the request_id middleware provided in oslo.
For v2, nova-specific middleware (compute_request_id.py) is used.
Therefore, v3 responses will have the header x-openstack-request-id,
and v2 responses will have the header x-compute-request-id (no
change). It is necessary to move the existing code out into
middleware, so that the old header is not attached to v3 responses.

UpgradeImpact: api-paste.ini is modified

DocImpact: v3 responses of the API will only include x-openstack-request-id

Implements: blueprint cross-service-request-id
Change-Id: I5e370fd3de5ee2f8a8d13553015d88910ff5ea87