How can I install MSSQL Server in a Python Docker image?

Question

I want to install MSSQL Server in a Python docker container to be able to run unit tests in a CI pipeline.

The problem is that the installation keeps failing. How can I fix it?

What I've tried

FROM python:3.7.9-slim-buster
RUN apt-get update

RUN apt-get -y install gnupg curl software-properties-common wget
RUN add-apt-repository "$(wget -qO- https://packages.microsoft.com/config/ubuntu/18.04/mssql-server-2019.list)"
RUN curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - \
    && apt-get update \
    && ACCEPT_EULA=Y DEBIAN_FRONTEND=noninteractive apt-get install -y \
    unixodbc-dev \
    mssql-server
ENV MSSQL_PID 'developer'
ENV MSSQL_SA_PASSWORD 'Devel0per'
RUN /opt/mssql/bin/mssql-conf -n setup accept-eula
ENV SQLALCHEMY_DATABASE_URI mssql+pyodbc://dev_user:Devel0per@localhost:5432/dev_db

This gives:

Step 8/9 : RUN /opt/mssql/bin/mssql-conf -n setup accept-eula
 ---> Running in f3cebdb5b946
Traceback (most recent call last):
  File "/opt/mssql/bin/../lib/mssql-conf/mssql-conf.py", line 361, in <module>
    main()
  File "/opt/mssql/bin/../lib/mssql-conf/mssql-conf.py", line 357, in main
    processCommands()
  File "/opt/mssql/bin/../lib/mssql-conf/mssql-conf.py", line 262, in processCommands
    COMMAND_TABLE[args.which]()
  File "/opt/mssql/bin/../lib/mssql-conf/mssql-conf.py", line 58, in handleSetup
    exit(mssqlconfhelper.setupSqlServer(True, noprompt=args.noprompt))
  File "/opt/mssql/lib/mssql-conf/mssqlconfhelper.py", line 971, in setupSqlServer
    if not checkInstall():
  File "/opt/mssql/lib/mssql-conf/mssqlconfhelper.py", line 941, in checkInstall
    return runScript(checkInstallScript, True) == 0
  File "/opt/mssql/lib/mssql-conf/mssqlconfhelper.py", line 930, in runScript
    return subprocess.call([sudo, "-EH", pathToScript])
  File "/usr/lib/python2.7/subprocess.py", line 172, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib/python2.7/subprocess.py", line 394, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1047, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory

Try 2

FROM mcr.microsoft.com/mssql/server:2019-latest
RUN apt-get update

gives

Step 2/2 : RUN apt-get update
 ---> Running in a1f0ef2cdd3f
Reading package lists...
E: List directory /var/lib/apt/lists/partial is missing. - Acquire (13: Permission denied)
The command '/bin/sh -c apt-get update' returned a non-zero code: 100

Answer 1

The second example should be:

FROM mcr.microsoft.com/mssql/server:2019-latest
USER root
RUN apt-get update && \
    # install python

USER mssql

Microsoft doesn't document it anywhere, but this image contains two users and sets the unpriviledged user mssql as the default one.