/usr/share/pyshared/swift/common/middleware/ is in python-swift 1.4.8-0ubuntu2.5.
This file is owned by root:root, with mode 0o755.
..
/usr/share/pyshared/swift/common/middleware/__init__.py
/usr/share/pyshared/swift/common/middleware/acl.py
/usr/share/pyshared/swift/common/middleware/catch_errors.py
/usr/share/pyshared/swift/common/middleware/cname_lookup.py
/usr/share/pyshared/swift/common/middleware/domain_remap.py
/usr/share/pyshared/swift/common/middleware/formpost.py
/usr/share/pyshared/swift/common/middleware/healthcheck.py
/usr/share/pyshared/swift/common/middleware/memcache.py
/usr/share/pyshared/swift/common/middleware/name_check.py
/usr/share/pyshared/swift/common/middleware/ratelimit.py
/usr/share/pyshared/swift/common/middleware/recon.py
/usr/share/pyshared/swift/common/middleware/staticweb.py
/usr/share/pyshared/swift/common/middleware/swift3.py
/usr/share/pyshared/swift/common/middleware/tempauth.py
/usr/share/pyshared/swift/common/middleware/tempurl.py