test-with-docker: allow built images to be used with "docker run" easily.

Configures the built container to enter into a script that
starts the minicluster. As a result, "docker run -ti <container>" will
launch the user into a shell with the Impala minicluster and the
impala development cluster running.

To handle cases where users don't specify --privileged, we skip
Kudu if it NTP seems unavailable.

Change-Id: Ib8d6a28d4cb4ab019cd72415024b23374a6d9e2f
Reviewed-on: http://gerrit.cloudera.org:8080/11781
Reviewed-by: Philip Zeyliger <philip@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>

docker/test-with-docker.py

@@ -653,6 +653,9 @@ class TestWithDocker(object):
       self.image = _check_output(
           ["docker", "commit",
            "-c", "LABEL pwd=" + self.git_root,
+           "-c", "USER impdev",
+           "-c", "WORKDIR /home/impdev/Impala",
+           "-c", 'CMD ["/home/impdev/Impala/docker/entrypoint.sh", "shell"]',
            container.id, "impala:built-" + self.name]).strip()
       logging.info("Committed docker image: %s", self.image)
     finally: