ssl problem when installing pip

I am installing TensorFlowOnSpark on a Google dataproc which also ready have Python and Openssl installed. I followed the guidance for Yarn cluster and met these question when running get-pip.py

pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting pip
  Could not fetch URL https://pypi.python.org/simple/pip/: There was a problem confirming the ssl certificate: Can't connect to HTTPS URL because the SSL module is not available. - skipping
  Could not find a version that satisfies the requirement pip (from versions: )
No matching distribution found for pip

[leewyang]

Yes, we require that each executor only runs one task at a time (and no dynamic allocation). The exact configuration depends on your spark version/setup, but you might be able to try --executor-cores 1.

[jzhusc]

@leewyang I think I find the reason. in 1 worker and 1 ps mode. they are 2 tasks in the one executor so that they have same ppid and will only create one node so we cannot start both ps and worker

by limiting one task for each executor. The problem is solved