Previously, S3ApiMiddleware.check_pipeline would always exit early
because the __file__ attribute of the Config instance passed to
check_pipeline was never set. The __file__ key is typically passed to
the S3ApiMiddleware constructor in the wsgi config dict, so this dict
is now passed to check_pipeline() for it to test for the existence of
__file__.
Also, the use of a Config object is replaced with a dict where it
mimics the wsgi conf object in the unit tests setup.
UpgradeImpact
=============
The bug prevented the pipeline order checks described in
proxy-server.conf-sample being made on the proxy-server pipeline when
s3api middleware was included. With this change, these checks will now
be made and an invalid pipeline configuration will result in a
ValueError being raised during proxy-server startup.
A valid pipeline has another middleware (presumed to be an auth
middleware) between s3api and the proxy-server app. If keystoneauth is
found, then a further check is made that s3token is configured after
s3api and before keystoneauth.
The pipeline order checks can be disabled by setting the s3api
auth_pipeline_check option to False in proxy-server.conf. This
mitigation is recommended if previously operating with what will now
be considered an invalid pipeline.
The bug also prevented a check for slo middleware being in the
pipeline between s3api and the proxy-server app. If the slo middleware
is not found then multipart uploads will now not be supported,
regardless of the value of the allow_multipart_uploads option
described in proxy-server.conf-sample. In this case a warning will be
logged during startup but no exception is raised.
Closes-Bug: #1912391
Change-Id: I357537492733b97e5afab4a7b8e6a5c527c650e4
6896f1f54b