[Python] Error 0A00014D when connecting to SQL Server using pyodbc and Docker on Render

I'm deploying a Python application using FastAPI, SQLAlchemy, and pyodbc to Render, and I'm facing the following error when trying to connect to my SQL Server database:

(pyodbc.Error) ('0A000', '[0A000] [Microsoft][ODBC Driver 18 for SQL Server]SSL Provider: [error:0A00014D:SSL routines::invalid version number] (-1) (SQLDriverConnect)')



I'm using Docker with the msodbcsql18 driver installed. Here's my connection setup:

#params = urllib.parse.quote_plus(
# f"DRIVER={{ODBC Driver 18 for SQL Server}};"
# f"SERVER={SERVER},{PORT};"
# f"DATABASE={DATABASE};"
# f"UID={USERNAME};"
# f"PWD={PASSWORD};"
# f"TrustServerCertificate=yes;"
# "Encrypt=no"
#)
#connection_string = f"mssql+pyodbc:///?odbc_connect={params}"
#engine = create_engine(connection_string)
#SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


I also tried using "Encrypt=yes" and "MinTLSVersion=1.0", but the error still occurs.

This is my Dockerfile:

FROM python:3.11-slim

ENV PYTHONDONTWRITEBYTECODE=1
ENV PYTHONUNBUFFERED=1
ENV OPENSSL_CONF=/etc/ssl/openssl.cnf

COPY openssl.cnf /etc/ssl/openssl.cnf

RUN apt-get update && apt-get install -y \
curl gnupg apt-transport-https unixodbc unixodbc-dev gcc g++ \
&& curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor | tee /etc/apt/trusted.gpg.d/microsoft.gpg > /dev/null \
&& echo "deb [arch=amd64 signed-by=/etc/apt/trusted.gpg.d/microsoft.gpg] https://packages.microsoft.com/debian/12/prod bookworm main" > /etc/apt/sources.list.d/mssql-release.list \
&& apt-get update && ACCEPT_EULA=Y apt-get install -y msodbcsql18 \
&& apt-get clean && rm -rf /var/lib/apt/lists/*

WORKDIR /app

COPY requirements.txt ./
RUN pip install --upgrade pip && pip install -r requirements.txt

COPY . .

EXPOSE 5000

CMD ["gunicorn", "app:app", "--bind", "0.0.0.0:5000"]


What I’ve tried:


Switching between ODBC Driver 17 and 18

Adding TrustServerCertificate=yes

Trying Encrypt=no and Encrypt=yes

Adding MinTLSVersion=1.0

Confirming that the database is accessible and credentials are valid

How can I fix the 0A00014D SSL/TLS error when using pyodbc inside a Docker container on Render? Is this related to TLS configuration, OpenSSL versions, or something with how Render handles outbound connections?

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