The grep regexp can match several lines if the haproxy pattern
is present.
By matching only the started by a whitespace it will match
the haproxy container listed by docker ps:
[...] Up 17 hours neutron-haproxy-qrouter
[...] Up 20 hours haproxy-bundle-docker-
Change-Id: Id63991e862ab10170c8afbde7a11677cc3d2e2f6
a472f7d513