In this tutorial we will be creating a AWS Lambda Python Layer that will include the Python Requests package and we will compile the package with Docker and the LambCI image.

Getting Started

First we will create the directory where we will store the intermediate data:

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$ mkdir lambda-layers
$ cd lambda-layers

Then we will create the directory structure, as you can see I will be using the python 3.8 runtime:

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$ mkdir -p requests/python/lib/python3.8
$ cd requests

Write the dependencies to the requirements file:

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$ echo "requests" > requirements.txt

Install dependencies locally using docker, where we will be using the lambci/lambda:build-python3.8 iamge and we are mounting our current working directory to /var/task inside the container, and then we will be running the command pip install -r requirements.txt -t python/lib/python3.7/site-packages/; exit inside the container, which will essentially dump the content to our working directory:

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$ docker run -v $PWD:/var/task \
   lambci/lambda:build-python3.8 \
   sh -c "pip install -r requirements.txt -t python/lib/python3.8/site-packages/; exit"

Zip up the deployment package that we will push to AWS Lambda Layers:

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$ zip -r package.zip python > /dev/null

Publish the layer using the aws cli tools, by specifying the deployment package, the compatible runtime and a identifier:

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$ aws --profile dev lambda \
   publish-layer-version --layer-name python-requests \
   --description "Python Requests using 3.8 Runtime" \
   --zip-file fileb://package.zip \
   --compatible-runtime "python3.8"

Then when you want to reference the layer on the functio that you want to create, you can do it like this:

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$ aws lambda create-function --function-name test-requests \
   --runtime python3.8 \
   --handler lambda_function.lambda_handler \
   --role "" --layers "arn:aws:lambda:eu-west-1:xxxxxxxxxxxx:layer:test-requests" \
   --code "S3Bucket=string,S3Key=string"

Thank You

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Credit to oznetnerd.com.