Pre-requisites: You need an Oracle client installed on the Python Notebook Server/Container to connect to the Oracle Database using cx_oracle connector. 

Steps to install Oracle Client  and configuration:  

1. Download an Oracle 21,19,12, or 11.2 "Basic" or "Basic Light" RPM compatible with your Oracle database from the below website and copy it into the Python Notebook server.

https://www.oracle.com/database/technologies/instant-client/linux-x86-64-downloads.html

Example: Basic Package (OL7 RPM) - oracle-instantclient-basic-21.11.0.0.0-1.x86_64.rpm
 
2. Log into the notebook container and move the client library under the location /data/shared/tds-notebooks which is the location of the persistent volume and Install the downloaded Oracle RPM package. 
       

yum install oracle-instantclient-basic-21.11.0.0.0-1.x86_64.rpm

3. It is required that environment variables like ORACLE_HOME, and LD_LIBRARY_PATH are configured. You can pass these environment variables to the notebooks container. To make these environment variables persistent we can tweak the docker-compose.yml file. Also, In the installers/current/compose/fragments shell script, under the tds-notebooks section, we can add these environment variables. 

4. The default location of the Oracle client library is /usr/lib please change it the /data/shared/tds-notebooks so that we don't lose it after the notebook restart. 


cx_Oracle Installation: 

1. Any additional package can be installed into the tds-notebooks image while building it. To do so, in the tds platform configure step we can add the package, conda:cx_oracle.
 
2. Stop the existing application, Drop the existing tds-notebook image, and rebuild it using $ tds platform build step. 

3. Once the notebook is built with a new image you can just import the package in all the notebooks. 

This is a standard procedure to add Python packages that will be available in the notebook environment.
 
Note: As it is not convenient to incorporate the username and password everywhere in Python scripts to establish the connection to the Oracle Database, we can save the text file to read a password from it by placing the file under /data/shared/tds-notebooks directory.