Allow users to specify a proxy for git repositories

[carbonin]

This PR uses my changes to rugged (libgit2/rugged#808) to allow users to configure a git repository proxy url.

This also builds on ManageIQ/manageiq-schema#406 which moved the embedded ansible proxy options to a top level setting so it could apply to all git repositories. We did this because it made it much easier to get the proxy options to the worktree instance from the GitRepository model. Without the settings change we would have to make the proxy settings conditional on whether or not the git repository instance existed because it was part of an embedded ansible configuration script source.

Plus automate domains get proxy support for free 😄

https://bugzilla.redhat.com/show_bug.cgi?id=1735712

TODO:

• Add more worktree specs
• Add git repository specs
• Test this for real

[NickLaMuro]

Minor change requested (just for the PR description):

Possibly include a brief mention as to why we are using our own fork of rugged instead of waiting for upstream to merge, just so this is searchable in the future and there is place documented as to the origination of this decision being made. I understand why, but other possibly doing some "git spelunking" in the future might not, and not everyone will be searching commit messages for this info either.

[NickLaMuro]

This pull request is not mergeable. Please rebase and repush.

Woops... my guess is this was my PR... 😄

[NickLaMuro]

Since I think I know the answer to the two questions I asked, I am going to just approve this PR.

Looks good to me. Nice work!

[Fryguy]

LGTM...just need to clean up the rubocops.

[Fryguy]

Just waiting on rubocops and the "Test this for real"

[carbonin]

Status here is I'm trying to test this with something similar to the ssh tunnel proxies described in the original proxy BZ https://bugzilla.redhat.com/show_bug.cgi?id=1475954

I was able to get the proxy info saved, but didn't provide a scheme which caused a segfault. Probably need a check for a valid url in the rugged code.

After getting past that, the request out to the proxy failed and hung on the first call. Still trying to work out what's happening there.

[carbonin]

I was able to get this to work by setting up a simple squid proxy server. The ssh (socks5) version isn't going to work for a variety of reasons.

But while testing that I noticed that the ssh-style repo urls raise an interesting error when we provide a proxy:

irb(main):006:0> Rugged::Repository.clone_at("[email protected]:ManageIQ/container-ruby.git", "./things", :proxy_url => "http://192.168.122.203:3128/")
Traceback (most recent call last):
       13: from bin/rails:4:in `<main>'
       12: from bin/rails:4:in `require'
       11: from railties (5.1.7) lib/rails/commands.rb:16:in `<top (required)>'
       10: from railties (5.1.7) lib/rails/command.rb:44:in `invoke'
        9: from railties (5.1.7) lib/rails/command/base.rb:63:in `perform'
        8: from thor (0.19.4) lib/thor.rb:369:in `dispatch'
        7: from thor (0.19.4) lib/thor/invocation.rb:126:in `invoke_command'
        6: from thor (0.19.4) lib/thor/command.rb:27:in `run'
        5: from railties (5.1.7) lib/rails/commands/console/console_command.rb:97:in `perform'
        4: from railties (5.1.7) lib/rails/commands/console/console_command.rb:17:in `start'
        3: from railties (5.1.7) lib/rails/commands/console/console_command.rb:62:in `start'
        2: from (irb):6
        1: from (irb):6:in `clone_at'
Rugged::SshError (authentication required but no callback set)

Assuming we're not going to hold this for authentication support, I figure we should only use the proxy for http(s) based repos, right?

[miq-bot]

Checked commits carbonin/manageiq@c6bce7a~...b1a6d95 with ruby 2.4.6, rubocop 0.69.0, haml-lint 0.20.0, and yamllint 1.10.0
5 files checked, 0 offenses detected
Everything looks fine. ⭐

[carbonin]

Removed WIP. This does what I feel like is the MVP to satisfy the regression in the timeframe we have.

Follow-up work to here and rugged itself would be needed to support credentials and ssh-style repo urls.

[Fryguy]

Yeah, we can support proxy + https right now...I'm not sure what callback they are looking for that we haven't already provided.

[simaishi]

Ivanchuk backport details:

$ git log -1
commit 7ae56390e57907c5b250d8ec369981c026f26bba
Author: Jason Frey <[email protected]>
Date:   Wed Aug 14 17:57:39 2019 -0400

    Merge pull request #19132 from carbonin/add_git_repo_proxy_url
    
    Allow users to specify a proxy for git repositories
    
    (cherry picked from commit cdbb3e781350718a6dfddc40bf1884bcca1ad924)
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1735712