gitserver: Could not resolve host: github.com

Created by: unknwon

I'm hitting this problem while running single Docker container (i.e. sourcegraph/server) both insiders and 3.19.0-rc.1.

The exact error message:

06:31:39                         gitserver | t=2020-08-16T06:31:39+0000 lvl=warn msg="error cloning repo" repo=github.com/sgtest/appdash err="error cloning repo: repo github.com/sgtest/appdash not cloneable: exit status 128 (output follows)\n\nfatal: unable to access 'https://github.com/sgtest/appdash/': Could not resolve host: github.com\n"

I suspect this is not specific to gitserver because when I shell into the container (both versions), I got the following results:

/ # ping github.com
ping: bad address 'github.com

I have complex proxy settings in my dev environment so I double checked an old version sourcegraph/server:3.18.0, which works perfectly.