This script creates a zip file for the AWS Lambda layer that includes AWSCLI.

zip-lambda-layer-awscli.sh

#!/usr/bin/env bash

# Prerequisites:
#  - pyenv
#  - virutalenv
#
# Usage:
# Run the following command if you want to create a zip file for Python 3.7 Lambda runtime 
# and you have installed Python 3.7.11 in your local computer with pyenv.
#
# $ sh zip-labmda-layer-awscli.sh 3.7.11

set -e

PYTHON_VER=$1
RE='([[:digit:]]+)\.([[:digit:]]+)\.([[:digit:]]+)'

if [[ $PYTHON_VER =~ $RE ]]
then
    MAJOR_VERSION=${BASH_REMATCH[1]}
    MINOR_VERSION=${BASH_REMATCH[2]}
    PYTHON_VER_SHORT="${MAJOR_VERSION}${MINOR_VERSION}"
else
    echo "Usage: $0 <python-version-in-pyenv>"
    echo "Example: $0 3.8.11"
    exit 1
fi

CURRENT_DIR=$PWD
WORK_DIR=/tmp/lambda-layer-awscli-$PYTHON_VER

rm -rf $WORK_DIR
mkdir $WORK_DIR


LAYER_FILE_DIR=$WORK_DIR/layer-files
VE_DIR=$WORK_DIR/venv

mkdir $LAYER_FILE_DIR
mkdir $LAYER_FILE_DIR/bin

cd $WORK_DIR
pyenv local $PYTHON_VER
virtualenv -p `pyenv which python` $VE_DIR

source $VE_DIR/bin/activate
pip install awscli
deactivate

cp $VE_DIR/bin/aws $LAYER_FILE_DIR/bin/
cp -r $VE_DIR/lib/python$MAJOR_VERSION.$MINOR_VERSION/site-packages/* $LAYER_FILE_DIR/bin/

perl -i -pe 's|#!.*|#!/var/lang/bin/python| if ($. == 1)' $LAYER_FILE_DIR/bin/aws

cd $LAYER_FILE_DIR
ZIPFILE=$CURRENT_DIR/lambda-layer-awscli-python$PYTHON_VER_SHORT.zip
rm -f $ZIPFILE
zip -r  $ZIPFILE *
echo "$ZIPFILE is created."