Jenkins server needs to honor https?_proxy vars set by Juju

[johnsca]

If Juju is configured to use a proxy, it will set the env vars for the charm context, but these won't be automatically carried over to the Jenkins server running as the jenkins user.

[kwmonroe]

Seems fixable by rendering a /var/lib/jenkins/proxy.xml template. This is what gets created when you add proxy info via the Jenkins UI Manage Jenkins -> Manage Plugins -> Advanced:

$ cat /var/lib/jenkins/proxy.xml
<?xml version='1.0' encoding='UTF-8'?>
<proxy>
  <name>my.proxy.url</name>
  <port>3128</port>
  <noProxyHost>10.55.60.207
127.0.0.1
::1</noProxyHost>
  <secretPassword>{AQAAABAAAAAQ0egWJilzTsMFBMlDf1myuboc8NDxwQRMuzPesmq5u2g=}</secretPassword>
</proxy>

These values came from a proxied jenkins deployment with [http|https|no]_proxy data from the ~/.juju-proxy file on the unit. I didn't set a password for the proxy, so I'm assuming the secretPassword value is some sort of salted/hashed representation of an empty string. I don't have an env with a proxy that requires creds, so I'm not sure how the charm should encode that value if present.

Alternatively, this could also be handled by setting the following in /etc/default/jenkins:

JAVA_ARGS="-Dhttp.proxyHost=my.proxy.url -Dhttp.proxyPort=3128

I don't like this as much because users won't see this info if they go poking around Manage Plugins -> Advanced in the Jenkins UI, nor do I know what the -D should be for no-proxy bits...

Just my $0.02 on possible fixes.