MEDIUM: log: add the client's SNI to the default HTTPS log format

During a troublehooting it came obvious that the SNI always ought to
be logged on httpslog, as it explains errors caused by selection of
the default certificate (or failure to do so in case of strict-sni).

This expectation was also confirmed on the mailing list.

Since the field may be empty it appeared important not to leave an
empty string in the current format, so it was decided to place the
field before a '/' preceding the SSL version and ciphers, so that
in the worst case a missing field leads to a field looking like
"/TLSv1.2/AES...", though usually a missing element still results
in a "-" in logs.

This will change the log format for users who already deployed the
2.5-dev versions (hence the medium level) but no released version
was using this format yet so there's no harm for stable deployments.
The reg-test was updated to check for "-" there since we don't send
SNI in reg-tests.

Link: https://www.mail-archive.com/haproxy@formilux.org/msg41410.html
Cc: William Lallemand <wlallemand@haproxy.org>
3 files changed