Merge lp:~michael.nelson/charms/trusty/squid-reverseproxy/1454485-set-visible-hostname into lp:charms/trusty/squid-reverseproxy

[Michael Nelson]

Add visible_hostname to avoid excessive DNS queries (bug 1454485)

See bug 1454485 for the details.

Tested locally with a (private) deployment upgrade at:
https://code.launchpad.net/~michael.nelson/canonical-mojo-specs/sca-upgrade-squid-visible-hostname/+merge/258956

Before upgrade:

dev-trusty# ~/charms/squid/trusty/squid-reverseproxy
$ juju run --service sca-cache "head /etc/squid3/squid.conf"
http_port 3128 accel vhost
acl PURGE method PURGE
acl CONNECT method CONNECT
...

After upgrade:
dev-trusty# ~/charms/squid/trusty/squid-reverseproxy
$ juju run --service sca-cache "head /etc/squid3/squid.conf"
visible_hostname michael-local-machine-3
http_port 3128 accel vhost
acl PURGE method PURGE
acl CONNECT method CONNECT
...

Locally I don't have any rDNS issues, but I've manually checked on our staging env to verify that adding the generated visible_hostname does stop the log messages (and from the squid code, the excessive DNS queries).

[Tim Van Steenburgh (tvansteenburgh)]

+1, LGTM, thanks Michael!

review: Approve

=== modified file 'hooks/hooks.py'
--- hooks/hooks.py	2015-03-25 17:31:27 +0000
+++ hooks/hooks.py	2015-05-13 04:49:21 +0000
@@ -257,6 +257,7 @@
         'refresh_patterns': refresh_patterns,
         'default_refresh_pattern': default_refresh_pattern,
         'need_localacl_defs': need_localacl_defs,
+        'visible_hostname': get_hostname(),
     }
     template = render_template('main_config.template', templ_vars)
     write_squid3_config('\n'.join(

=== modified file 'templates/main_config.template'
--- templates/main_config.template	2015-01-20 15:54:55 +0000
+++ templates/main_config.template	2015-05-13 04:49:21 +0000
@@ -1,3 +1,4 @@
+visible_hostname {{ visible_hostname }}
 http_port {{ config.port }} {{ config.port_options }}
 {% if config.enable_https -%}
 https_port {{ config.https_port }} {{ config.https_options }} cert={{ config.ssl_certfile }} key={{ config.ssl_keyfile }}