Building OpenCV for AWS Lambda Python

BUILD_AWS_LAMBDA.md

To build OpenCV3.0 for AWS Lambda Python

Summary

Because AWS Lambda runs in a Amazon Linux environment, to run external modules you must

Create the OpenCV build environment

sudo yum update -y
sudo yum install gcc-c++ cmake python27-pip -y

To build the OpenCV run the following in the home directory of the EC2

1. Download OpenCV
2. Create a project virtual environment and install numpy
3. Build OpenCV

cd 
wget https://github.com/opencv/opencv/archive/3.2.0.zip
virtualenv project
source project/bin/activate
pip install numpy
mkdir local
unzip opencv-3.2.0.zip
cd opencv-3.2.0
mkdir build
cd build
cmake -D CMAKE_BUILD_TYPE=RELEASE -D BUILD_SHARED_LIBS=NO -D WITH_FFMPEG=ON -D BUILD_opencv_python2=ON -D CMAKE_INSTALL_PREFIX=~/local ~/opencv-3.2.0
make
make install
cp ~/local/lib/python2.7/site-packages/cv2.so ~/project/lib64/python2.7/site-packages/

As an example, to run the hello.py in AWS Lambda.

from __future__ import print_function

import cv2
import numpy as np
import boto3

def lambda_handler(event, context):
    print(cv2.__version__)
    print(np.__version__)
    print("hello")
    return event['key1']  # Echo back the first key value

Run the following command to zip the dependencies and hello.py and upload to s3

Important Note: The script must be world readable

chmod u=rwx,go=r hello.py
zip -9 bundle.zip hello.py 
cd $VIRTUAL_ENV/lib/python2.7/site-packages
zip -r9 ~/bundle.zip *
cd $VIRTUAL_ENV/lib64/python2.7/site-packages/
zip -r9 ~/bundle.zip *
cd
aws s3 cp bundle.zip s3://<S3 BUCKET HERE>/S3/KEY/HERE/bundle.zip

This will allow you to run manual tests in AWS Lambda via the console