Failed to resolve hostname from containers managed by OpenShift v3

Issue

• When I tried to s2i build with internal gitserver, I got following error and failed to build.

E1006 03:21:45.329743       1 git.go:102] Clone failed: fatal: unable to access 'http://gitserver.example.com/foo/bar/testgit/': Failed connect to gitserver.example.com:80; Operation now in progresst
I1006 03:21:45.329782       1 clone.go:35] Git clone failed: exit status 128

• I set up internal git repositories followed by How to use internal git repositories with Openshift , and the setup is no problem.

• Or when I tried to use external gitserver, it returns Connection timed out below.

E0823 08:59:07.653475       1 git.go:127] fatal: unable to access 'https://github.com/foo/ruby-hello-world/': Failed connect to github.com:443; Connection timed out
I0823 08:59:07.656487       1 clone.go:29] Git clone failed: exit status 128

• I started hitting this issue after update to v3.0.1.0 or later.