Swift broken when headers exceed 8k

This is related to deployments that using PKI/PKIZ for tokens and have more than 1 region.

Due to token becomes large (> 8k) swift can't process such requests and breaks with:

EBUG:iso8601.iso8601:Got u'55' for 'second' with default None
INFO:urllib3.connectionpool:Starting new HTTP connection (1): 10.109.64.3
DEBUG:urllib3.connectionpool:Setting read timeout to <object object at 0x7f7b2e0af090>
DEBUG:urllib3.connectionpool:"HEAD /v1/AUTH_e46f34918675465e888114f30753b180 HTTP/1.1" 400 0
INFO:swiftclient:REQ: curl -i http://10.109.64.3:8080/v1/AUTH_e46f34918675465e888114f30753b180 -I -H "X-Auth-Token: PKIZXXX"
INFO:swiftclient:RESP STATUS: 400 Header Line Too Long
INFO:swiftclient:RESP HEADERS: [('date', 'Wed, 01 Jul 2015 22:53:31 GMT'), ('content-length', '0'), ('content-type', 'text/html; charset=UTF-8'), ('x-trans-id', 'tx596786fa2e8145839e447-0055946f6b')]
ERROR:swiftclient:Account HEAD failed: http://10.109.64.3:8080/v1/AUTH_e46f34918675465e888114f30753b180 400 Header Line Too Long
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/swiftclient/client.py", line 1243, in _retry
    rv = func(self.url, self.token, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/swiftclient/client.py", line 528, in head_account
    http_response_content=body)
ClientException: Account HEAD failed: http://10.109.64.3:8080/v1/AUTH_e46f34918675465e888114f30753b180 400 Header Line Too Long
Traceback (most recent call last):
  File "/usr/bin/swift", line 10, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/dist-packages/swiftclient/shell.py", line 1287, in main
    globals()['st_%s' % args[0]](parser, argv[1:], output)
  File "/usr/lib/python2.7/dist-packages/swiftclient/shell.py", line 492, in st_stat
    stat_result = swift.stat()
  File "/usr/lib/python2.7/dist-packages/swiftclient/service.py", line 443, in stat
    raise SwiftError('Account not found', exc=err)
swiftclient.service.SwiftError: 'Account not found'

This can be fixed by adding to swift.conf:

[swift-constraints]
max_header_size=<number>

And restarting services.