This patch add the node_exporter to the docker image. It install it create and run a service with it. After this patch node_exporter will run and will be part of scylla Docker image. Fixes #4300 Signed-off-by: Amnon Heiman <amnon@scylladb.com> Message-Id: <20190421130643.6837-1-amnon@scylladb.com>