The scripts are:

  split-varnish-logs

    Perl script to process the varnishlog output file using varnishncsa, and
    write each line into a different logfile depending on the hostname.

    The sites to create logs for must be configured in the start of this
    script. There's also a bit which skips 10.x addresses which you might want
    to remove or modify.

    Invocation:

      split-varnish-logs <filename> <suffix>

    where "filename" is the name of the 'varnishlog' output file, and "suffix"
    is a string to append to the end of the output names (configured in the
    script itself). Typically this is '.log'.

  rotate-varnish-logs

    Bash script to rotate the varnishlog output file, signal it to create a
    new one, and then invoke 'split-varnish-logs' to create the site-specific
    logfiles.

    There's a few things to configure at the start. The script takes no
    parameters and I run it using cron every hour.

    It also changes the ownership of files to "awstats" so you'll probably
    want to remove or change that to suit your setup.