Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1739962

Description of problem:

In an intermediate-to-large environment, running `opt/puppetlabs/bin/puppet cert --ssldir /etc/puppetlabs/puppet/ssl --list --all` takes about 90s. This causes the UI that lists the puppet CA certs timeout as the default read timeout is 60s. The workaround is to increase proxy_request_timeout, however the user experience is still really bad((loading the page takes 1-2 minutes). In contrast, running 'puppetserver ca list --all` only takes 3s. As you can see, the difference of listing the certs is huge so I think we should change the foreman-proxy to use puppetserver ca command instead of the old puppet command.

Version-Release number of selected component (if applicable):

6.5

How reproducible:

Normal

Steps to Reproduce:

The slowness is only observed in the cus's env.

[root@lp000xslnx0005 ~]# time puppetserver ca list --all | grep real

real 0m3.556s
user 0m1.078s
sys 0m0.099s
[root@lp000xslnx0005 ~]# time /opt/puppetlabs/bin/puppet cert --ssldir /etc/puppetlabs/puppet/ssl --list --all| grep real
Warning: `puppet cert` is deprecated and will be removed in a future release.
(location: /opt/puppetlabs/puppet/lib/ruby/vendor_ruby/puppet/application.rb:370:in `run')

real 1m30.963s
user 1m29.257s
sys 0m0.578s

Actual results:

The UI is slow.

Expected results:

The UI shouldn't take 1-2 mins to load.