pyodbc and unixODBC for MSSQL as a lambda layer

pyodbc-unixODBC-lambda-layer

# use https://github.com/lambci/docker-lambda to simulate a lambda environment
docker run -it --rm --entrypoint bash -e ODBCINI=/opt/odbc.ini -e ODBCSYSINI=/opt/ lambci/lambda:build-python3.7

# download and install unixODBC
# http://www.unixodbc.org/download.html
curl ftp://ftp.unixodbc.org/pub/unixODBC/unixODBC-2.3.7.tar.gz -O
tar xzvf unixODBC-2.3.7.tar.gz
cd unixODBC-2.3.7

./configure --sysconfdir=/opt --disable-gui --disable-drivers --enable-iconv --with-iconv-char-enc=UTF8 --with-iconv-ucode-enc=UTF16LE --prefix=/opt
make
make install

cd ..
rm -rf unixODBC-2.3.7 unixODBC-2.3.7.tar.gz

# download and install ODBC driver for MSSQL 17
# https://docs.microsoft.com/en-us/sql/connect/odbc/linux-mac/installing-the-microsoft-odbc-driver-for-sql-server?view=sql-server-2017
curl https://packages.microsoft.com/config/rhel/6/prod.repo > /etc/yum.repos.d/mssql-release.repo
yum install e2fsprogs.x86_64 0:1.43.5-2.43.amzn1 fuse-libs.x86_64 0:2.9.4-1.18.amzn1 libss.x86_64 0:1.43.5-2.43.amzn1
ACCEPT_EULA=Y yum install msodbcsql17 --disablerepo=amzn*
export CFLAGS="-I/opt/include"
export LDFLAGS="-L/opt/lib"

cd /opt
cp -r /opt/microsoft/msodbcsql17/ .
rm -rf /opt/microsoft/

# install pyodbc for use with python.
# Notice the folder structure to support python 3.7 runtime 
# https://docs.aws.amazon.com/lambda/latest/dg/configuration-layers.html#configuration-layers-path
mkdir /opt/python/
cd /opt/python/
pip install pyodbc -t .

cd /opt
cat <<EOF > odbcinst.ini
[ODBC Driver 17 for SQL Server]
Description=Microsoft ODBC Driver 17 for SQL Server
Driver=/opt/msodbcsql17/lib64/libmsodbcsql-17.3.so.1.1
UsageCount=1
EOF

cat <<EOF > odbc.ini
[ODBC Driver 17 for SQL Server]
Driver = ODBC Driver 17 for SQL Server
Description = My ODBC Driver 17 for SQL Server
Trace = No
EOF

# package the content in a zip file to use as a lambda layer
cd /opt
zip -r9 ~/pyodbc-layer.zip .

# to test it locally:
# unzip the content of your layer to your local environment, to /var/opt/ for example:
unzip pyodbc-layer.zip -d /var/opt/

# In your local environment, have your lambda function handy at /var/task/lambda_function.py

import pyodbc
server = 'myserver'
database =  'mydb'
username = 'myuser'
password = 'mypwd'

def lambda_handler(event, context):
    # TODO implement
    cnxn = pyodbc.connect('DRIVER={ODBC Driver 17 for SQL Server};SERVER='+server+';DATABASE='+database+';UID='+username+';PWD='+ password)
    cursor = cnxn.cursor()
    cursor.execute("select @@version;")
    row = cursor.fetchone()
    while row:
        print(row[0])
        row = cursor.fetchone()

# Time to test
docker run --rm -v /var/task:/var/task -v /var/opt:/opt lambci/lambda:python3.7 lambda_function.lambda_handler '{"some": "event"}'

# useful links
https://medium.com/devopslinks/aws-lambda-microsoft-sql-server-how-to-66c5f9d275ed
https://stackoverflow.com/questions/47682991/aws-lambda-function-to-connect-to-sql-server-with-python
https://gist.github.com/carlochess/658a98589709f46dbb3d20502e48556b

@davidcomerford When I try and build the layer using the Dockerfile I get the error below. This has something to do with the file libmsodbcsql-18.3.so.2.1 which is in the pre-built layer but i have this version libmsodbcsql-18.5.so.1.1 in the custom built layer. When I add the older version into the custom built layer, everything works as expected. Is there a compatibility issue with the new version? I don't want to hardcode the versions in the Dockerfile (I get an error when trying to do this anyway)

[01000] [unixODBC][Driver Manager]Can't open lib 'ODBC Driver 18 for SQL Server' : file not found (0) (SQLDriverConnect)