Log Message:
Update to 20190424. From the changelog:

Some vpn clients pass multiple domains for DNS search scope, which
requires that we use search rather than domain. The generic path was
already using search, so just switch the resolvconf path to also use
search.

In a container, /etc/nsswitch.conf might not exist.
Silence the error grep: /etc/nsswitch.conf: No such file or directory

Inside a container, running 'ip route flush cache' can spam with
"ip: can't open '/proc/sys/net/ipv4/route/flush': Read-only file system"
Hide that the error output for that command.