A demonstration project and template to deploy a AWS Lambda Function with Scikit-learn, Pandas, Numpy and SciPy based on the layers provided by AWSLambdas.com.

Scikit-learn is a machine learning library that supports supervised and unsupervised learning. It also provides various tools for model fitting, data preprocessing, model selection and evaluation, and many other utilities. Additionally to Scikit-learn, NumPy and SciPy, this layer includes Pandas as well which all together create a very common and popular bundle that you can now leverage within AWS Lambdas.

Before you start, make sure you have installed the latest version of the AWS CLI and the AWS Serverless Application Model (SAM).

git clone https://github.com/AwsLambdas/aws-lambda-scikit-learn.git

• How to create a Scikit-learn layer from AWS Lambdas GUI
• How to create a Scikit-learn layer from a zip file
• How to create a Lambda with a Scikit-learn layer attached

Our Scikit-learn's layer, which includes Pandas, Numpy and SciPy as well, is available for purchasing in AWSLambdas.com.

Right after the payment, you will be able to click the button "Deploy to AWS".

Enter the region, and credentials with enough permission to create a Lambda layer.

Click the button "Create Layer", and your layer will be created in a few seconds. Copy to the clipboard the returned ARN value and follow the instructions: How to create a Lambda with a Scikit-learn layer attached

Our Scikit-learn's layer, which includes Pandas, Numpy and SciPy as well, is available for purchasing in AWSLambdas.com.

Right after the payment, you will be able to click the "Download" button. Then, copy the zip file to your project clone's root directory.

To simplify the process, let's create some environment variables.

export AWSL_RUNTIME=python3.8
export AWSL_RAMDOM=$RANDOM-$RANDOM
export AWSL_LAYER_NAME=awslambdas-com-python38-scikit-learn0241
export AWSL_BUCKET=awslambdas-com-$AWSL_RAMDOM
export AWSL_LAYER_PACKAGE=$AWSL_LAYER_NAME.zip

You need a bucket to store the layer's zip file.

aws s3 mb s3://$AWSL_BUCKET

aws s3 cp $AWSL_LAYER_PACKAGE s3://$AWSL_BUCKET/$AWSL_LAYER_PACKAGE

aws lambda publish-layer-version \
    --layer-name $AWSL_LAYER_NAME \
    --license-info "MIT" \
    --content S3Bucket=$AWSL_BUCKET,S3Key=$AWSL_LAYER_PACKAGE \
    --compatible-runtimes $AWSL_RUNTIME

Copy to the clipboard the value of "LayerVersionArn" from the command response and follow the instructions: How to create a Lambda with a Scikit-learn layer attached

This project is a ready-to-use template to create and deploy an AWS Lambda using the AWS Serverless Application Model (SAM).

Please, review the template.yaml file. Notice that the template will create two ressources: an API Gateway and a Lambda function.

Replace the text "PASTE HERE YOUR LAYER ARN" with the ARN previously obtained.

To simplify the process, let's create a couple of environment variables.

export AWSL_RAMDOM=$RANDOM-$RANDOM
export AWSL_STACK_NAME=awslambdas-com-lambda-scikit-learn

AWS SAM need this to store some information about the deployment.

aws s3 mb s3://$AWSL_STACK_NAME-$AWSL_RAMDOM

The Lambda to be deployed is very simple. It trains a very simple model and makes a prediction. You can see the code in the file: src/app.py

import json
import pandas as pd
from sklearn import model_selection, linear_model, exceptions

def lambda_handler(event, context):
    model = train_logistic_regression()
    prediction = model.predict([[6.4,2.9,4.3,1.3]])
    return {
        "statusCode": 200,
        "body": json.dumps({
            "message": "Predicting Iris class for [6.4,2.9,4.3,1.3]: {}".format(prediction)
        }),
    }

Run the following commands to build and deploy the project to AWS:

sam build
sam deploy --stack-name $AWSL_STACK_NAME --s3-bucket $AWSL_STACK_NAME-$AWSL_RAMDOM --capabilities CAPABILITY_IAM

To test your Lambda, copy the value of the "API URL" from the previous command Outputs and you can call it with curl or just open it in a browser.

curl "API URL"

You should see the following response coming from your Lambda:

{"message": "Predicting Iris class for [6.4,2.9,4.3,1.3]: ['Iris-versicolor']"}

Congratulations! You have now a base Lambda project that you can use to build on top of it.

Remove the Lambda and Api Gateway

aws cloudformation delete-stack --stack-name $AWSL_STACK_NAME

Wait a few seconds to allow the previous command to finish. Then, use the following commands to remove the s3 buckets.

aws s3 rb s3://$AWSL_STACK_NAME-$AWSL_RAMDOM --force

# If the zip file was used
aws s3 rb s3://$AWSL_BUCKET --force