Access external SQL server from inside of Docker

I am having a really hard time getting my docker container to access the MS SQL server. I have tried following this guide here, but to no avail.

Here is my Base Dockerfile:

FROM python:3
ADD ./odbcinst.ini /etc/odbcinst.ini
RUN apt-get update && apt-get install gcc
RUN apt-get install -y tdsodbc unixodbc-dev
RUN apt-get install unixodbc-bin -y
RUN apt-get clean -y
RUN apt-get update && apt-get install -y gcc unixodbc-dev mssql-python-pyodbc

RUN pip install pyodbc
RUN pip install plaster_pastedeploy pyramid pyramid_jinja2 pyramid_debugtoolbar waitress yagmail pyodbc

And here is the other docker file that extends it:

FROM pyodbc
COPY . .
RUN pip install -e companalysis/
CMD [ "pserve", "companalysis/development.ini" ]
EXPOSE 8081

and here is my sql connection string:

strconn = 'DRIVER=
{FreeTDS};SERVER=192.168.0.6;
DATABASE=xxxx;UID=xxxx;PWD=xxx'

and no matter what I do I get this error:

Error: ('01000', u"[01000] [unixODBC][Driver Manager]Can't open lib 'FreeTDS' : file not found (0) (SQLDriverConnect)")

I would love some assistance on this. EDIT: I have gotten it to install with this in my dockerfile:

I got it to properly install the driver with this in my dockerfile:

RUN echo "[FreeTDS]\n\
Description = FreeTDS unixODBC Driver\n\
Driver = /usr/lib/x86_64-linux-gnu/odbc/libtdsodbc.so\n\
Setup = /usr/lib/x86_64-linux-gnu/odbc/libtdsS.so" >> /etc/odbcinst.ini
RUN export PYMSSQL_BUILD_WITH_BUNDLED_FREETDS=1
RUN apt-get update && apt-get install -y unixodbc unixodbc-dev freetds-dev freetds-bin tdsodbc