Shout out to @estesp for the idea. Some use cases of
`readContainerFile` can be replaced with `docker exec $id cat $file`.
This helper method can eliminate the requirement that
host/cli should be on the same machine.
TestRunMutableNetworkFiles and TestRunResolvconfUpdater still
need to access the docker host filesystem as they modify
the file directly from there assuming cli and daemon are
on the same machine.
This fixes TestLinksUpdateOnRestart and TestLinksHostsFilesInject
for Windows CI.
Signed-off-by: Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
Upstream-commit: 6bbb456138e48c7558cfe5c797c57d136f1a694b
Component: engine
5db21189fd