Shutting down all kernels managed by NB2KG doesn't work when SSL is enabled

[kevin-bates]

When issuing jupyter notebook stop $portnum with SSL configured, active notebooks fail to shutdown. Here are the steps...

1) Start Jupyter Enterprise Gateway (or Kernel Gateway) with self-signed cert and key: export KG_KEYFILE=${keyFilePath} export KG_CERTFILE=${sslCertPath}

2) Start Jupyter notebook (using same cert and key as 1))

• Enable SSL for NB2KG communication with JEG export VALIDATE_KG_CERT=no <---- skip cert_verification errors. export KG_CLIENT_KEY=${keyFIlePath} export KG_CLIENT_CERT=${sslCertPath}

3) Start remote kernel (remote kernel starts)

4) Attempt to stop Jupyter notebook server by issuing the following command, jupyter notebook stop $portnum

• Expect: Jupyter notebook server shutdown trigger shutdown_all kernels
• Actual: Jupyter notebook server shuts down ok, however, the kernels are not killed and still running.

Nothing is posted in the JEG log. In the notebook/nb2kg log, however, is the following error:

[W 08:58:44.869 NotebookApp] SSL Error on 17 ('::1', 55238, 0, 0): [SSL: TLSV1_ALERT_UNKNOWN_CA] tlsv1 alert unknown ca (_ssl.c:749)