django.db.utils.DatabaseError: Error while trying to retrieve text for error ORA-01804 - python-3.x

Question

Q1. What versions are we using?
Ans.
Python 3.6.12
OS : CentOS 7 64-bit
DB : Oracle 18c
Django 2.2
cx_Oracle : 8.1.0
Q2. Describe the problem
Ans. While running server with "python3 manage.py runserver"
application is able to contact Oracle DB and show the Django Administration page and login also works.
But when we access the application using the Apache (HTTPD) based URL over secure SSL port, we do see the Django page and the admin page as well but Login to Admin page with Internal server error.
In the logs, we see
"django.db.utils.DatabaseError: Error while trying to retrieve text for error ORA-01804"
cx_oracle is otherwise able to connect to the database properly, another application is also using the same database behind the same httpd proxy and works fine
Q3. Show the directory listing where your Oracle Client libraries are installed (e.g. the Instant Client directory). Is it 64-bit or 32-bit?
Ans. 64-bit
Q4. Show what the PATH environment variable (on Windows) or LD_LIBRARY_PATH (on Linux) is set to?
LD_LIBRARY_PATH=/srv/vol/db/oracle/product/18.0.0/dbhome_1/lib:/lib:/usr/lib
PATH=$ORACLE_HOME/bin:/srv/vol/db/oracle/product/18.0.0/dbhome_1/lib:$PATH
Q5. Show any Oracle environment variables set (e.g. ORACLE_HOME, ORACLE_BASE).
ORACLE_HOME=/srv/vol/db/oracle/product/18.0.0/dbhome_1
TNS_ADMIN=$ORACLE_HOME/network/admin
NLS_LANG=AMERICAN_AMERICA.AL32UTF8
ORACLE_BASE=/srv/vol/db/oracle
CLASSPATH=$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib:$ORACLE_HOME/lib
Any suggestions/help is highly appreciated.
Thank you

Answer 1

I found the problem
So I just removed all the variable declarations from /etc/sysconfig/httpd and checked, the application was still able to access the lib files, so these were now redundant.
Then undid all variable declarations done earlier in .localsh and .localrc files for the os users. To start from scratch, and go step by step to see where it breaks.
So now, cx_Oracle was looking for the lib files in wrong directory
$ORACLE_HOME/client_1/lib
instead of
$ORACLE_HOME/lib
DPI-1047: Cannot locate a 64-bit Oracle Client library: "$ORACLE_HOME/client_1/lib/libclntsh.so: cannot open shared object file: No such file or directory". See https://cx-oracle.readthedocs.io/en/latest/user_guide/installation.html for help
I did not have any subfolder named "client_1" inside dbhome_1
so I just created a symlink client_1 that points to dbhome_1 (still unsure on this, but at least it works :) )
So, now, this error was gone but now again ORA-01804 was coming. 😑
I had read somewhere that this error can be fixed by adding "libociei.so" but I did not have one on my instance, so I generated it using these commands:-
mkdir -p $ORACLE_HOME/rdbms/install/instantclient/light
cd $ORACLE_HOME/rdbms/lib
make -f ins_rdbms.mk igenliboci
Then I just moved this libociei.so file from
$ORACLE_HOME/instantclient to $ORACLE_HOME/lib
Now there was a new error (so.. progress 😉 ):
ORA-12546 - TNS Permission Denied.
This was easy to solve 😀
I used this command to address this :-
setsebool -P httpd_can_network_connect on
And...... That was all! It worked.