Comment 5 for bug 1734144

It looks like there is a small window of time where the size reported by the HEAD request for the 'content-length' is incorrect.
Duplicity says in the log it expects 262197953 bytes but the response says 262197945 bytes.
Manually verifiying the file later confirms it is 262197953 bytes.

Note that there also appears to be a varnish server before the objectstore, potentially influencing the header.

# Latest error reported by duplicity:
ERROR 44 'redacted.server.duplicity-full.20180103T071647Z.vol590.difftar.gpg' 262197953 262197945
. File redacted.server.duplicity-full.20180103T071647Z.vol590.difftar.gpg was corrupted during upload.

# Manually getting stats:
$ swift stat cloudvps-boss-backup redacted.server.duplicity-full.20180103T071647Z.vol590.difftar.gpg
       Account: *redacted*.objectstore.eu
     Container: cloudvps-boss-backup
        Object: redacted.server.duplicity-full.20180103T071647Z.vol590.difftar.gpg
  Content Type: application/octet-stream
Content Length: 262197953
 Last Modified: Thu, 04 Jan 2018 05:28:42 GMT
          ETag: ccde4ec46420555b92231f79c3bf04da
     X-Varnish: 1371704766
           Via: 1.1 varnish
 Accept-Ranges: bytes, bytes
   X-Timestamp: 1515043721.11970
    X-Trans-Id: txcc1d645658b4b1609cbd4-dfea3105a4
           Age: 0

# Manually downloading the file:
$ swift download cloudvps-boss-backup redacted.server.duplicity-full.20180103T071647Z.vol590.difftar.gpg
redacted.server.duplicity-full.20180103T071647Z.vol590.difftar.gpg [auth 2.054s, headers 4.720s, total 16.679s, 17.928 MB/s]

# Checking the size:
$ wc -c < redacted.server.duplicity-full.20180103T071647Z.vol590.difftar.gpg
262197953