Error in oracle instant client in docker with python image

[Weiyi-Chung]

Hi Community,

I'm using FastAPI with Oracle 19c. Recently, I tried migrating to Thick mode.
Initially, I tested it locally by using the Instant Client for macOS (ARM64) version on my MacBook, and it worked fine.

Afterward, I wanted to add the installation steps into my Dockerfile for deployment via Docker on Kubernetes. However, I encountered some issues.
At first, there were path-related problems, but after some digging and fixing, I realized there might be a more fundamental issue:
the base images I tried, such as python:3.12-alpine and python:3.12.2-slim-bookworm, are built with musl instead of glibc.
Because of this, some necessary functionalities expected by the Oracle Instant Client are missing, leading to runtime issues.

Since I'm not very familiar with C-level system differences, I'm not entirely sure if this understanding is accurate. Is there any suggestion of this problem?

• Minimal reproducible example:

FROM python:3.12-alpine

ARG SERVICE_HOME=/opt/backend

USER root

# Install common packages and database drivers
RUN apk add --no-cache \
    bash \
    gcc \
    musl-dev \
    libffi-dev \
    openssl-dev \
    unixodbc \
    libaio

# Download and setup Oracle Instant Client
WORKDIR ${SERVICE_HOME}
RUN wget https://download.oracle.com/otn_software/linux/instantclient/1927000/instantclient-basic-linux.x64-19.27.0.0.0dbru.zip \
    && unzip instantclient-basic-linux.x64-19.27.0.0.0dbru.zip \
    && rm instantclient-basic-linux.x64-19.27.0.0.0dbru.zip \
    && cd instantclient_19_27 \
    && rm -f *jdbc* *occi* *mysql* *README *jar uidrvci genezi adrci \
    && mkdir -p lib \
    && mv *.so* lib/ \
    && mv network lib/ \
    && cd ..

ENV LD_LIBRARY_PATH="${SERVICE_HOME}/instantclient_19_27" \
    ORACLE_HOME="${SERVICE_HOME}/instantclient_19_27" \
    PATH="${SERVICE_HOME}/instantclient_19_27:${PATH}"

# Create application user and working directory
RUN adduser -D -s /bin/bash backend-user \
    && mkdir -p ${SERVICE_HOME} && chown -R backend-user:backend-user ${SERVICE_HOME}

WORKDIR ${SERVICE_HOME}

# Set permissions
RUN chown -R backend-user:backend-user ${SERVICE_HOME}

# Install Python packages
RUN pip3 install oracledb==2.4.0

# Final working directory
WORKDIR ${SERVICE_HOME}

• Installation command (with docker damon on)

docker build -t test-backend .
docker rm -f test-backend && docker run -it --name test-backend test-backend /bin/bash

• After enter shell in container

import oracledb
oracledb.init_oracle_client()

• Error:

>>> import oracledb
>>> oracledb.init_oracle_client()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "src/oracledb/impl/thick/utils.pyx", line 494, in oracledb.thick_impl.init_oracle_client
  File "src/oracledb/impl/thick/utils.pyx", line 519, in oracledb.thick_impl.init_oracle_client
  File "src/oracledb/impl/thick/utils.pyx", line 446, in oracledb.thick_impl._raise_from_info
oracledb.exceptions.DatabaseError: DPI-1047: Cannot locate a 64-bit Oracle Client library: "Error loading shared library libnnz19.so: No such file or directory (needed by /opt/backend/instantclient_19_27/lib/libclntsh.so)". See https://python-oracledb.readthedocs.io/en/latest/user_guide/initialization.html for help
Help: https://python-oracledb.readthedocs.io/en/latest/user_guide/troubleshooting.html#dpi-1047

I think I have this file under lib

e9e656b9d054:/opt/backend/instantclient_19_27/lib# ls
libccme_asym.so           libccme_ecc.so            libclntsh.so.10.1         libclntsh.so.18.1         libcryptocme.so           libnnz19.so
libccme_base.so           libccme_ecc_non_fips.so   libclntsh.so.11.1         libclntsh.so.19.1         libipc1.so                libociei.so
libccme_base_non_fips.so  libclntsh.so              libclntsh.so.12.1         libclntshcore.so.19.1     libmql1.so                network

Thanks in advance for any advice or suggestions!

Note: Is there any recommendation for a better Docker base image when using FastAPI + Oracle 19c with Instant Client support? (I'v already tried to use oraclelinux:9, but I would like to use python base image instead)