Proxy server additions

[reynn]

PR 171 has additions to support proxy servers for sending slack notifications however this did not allow us to use it if we had a non-standard proxy server port (in my case 3128 instead of 8080), these additions allow any proxy server port as well as use of the slackSend workflow step.

[facastagnini]

LGTM!

[facastagnini]

What is the process to get PRs merged in this project? I can see a long backlog of PRs

[kmadel]

@facastagnini #247 is considered a severe security issue per Jira - so until we can get one more thumbs up on that PR and get it merged and release, there will no other merges.

[kmadel]

Actually see #171 - Jenkins has a proxy config that should be used, along with support for the 'no proxy host' list.

[developerinlondon]

any chance this can be resolved as we really need this feature?

[kmadel]

@developerinlondon Conflicts must be resolved
There is also not full test coverage
And the README should be updated as that will be the primary source of documentation moving forward.

[serg3k]

@reynn @developerinlondon what is your use case for this?
Slack Plugin uses Jenkins system proxy.
There was proxy issue in 1.8 that was kindly resolved by @jiamengyu in #299

I would agree with #171 (comment) there is no need to have plugin-specific proxy configuration.

[caleyg]

@nevermindr so you're saying I have to setup jenkins proxy configurations to get this plugin to honor proxy settings?

That would be an anti pattern dont you think? This is a java plugin. It should use default java settings.

[serg3k]

@caleyg this PR introduces additional configuration parameter proxyServerURL to plugin that allows to set plugin-specific HTTP proxy, which I think is an overkill because Jenkins already gives you ability to configure custom proxyPort.
You could file new issue/PR for discussion, if you think that this plugin should preferably use JVM proxy settings.