GeoSpatial Lambda Layer

Python geospatial lambda layer including:

• shapely
• osgeo
• rasterio
• numpy
• pillow

Deploy

Prerequisites:

• awscli
• aws-sam-cli
• docker
• make
• awscfncli2

Deploy:

$ make
$ AWS_PROFILE=<your-profile-here> make deploy

Note the make will pull and build a very large docker image and may take a while. Goto geo_layer and run docker build . to see what's happening if you encounter problems.

After everything is deployed, check stack output:

$ cfn-cli --profile=<your-profile-here> status -e
Default.GeoLamb
StackName: GeoLambHelloWorld
Status: CREATE_COMPLETE
StackID: arn:aws:cloudformation:us-east-1:1234567890:stack/GeoLambHelloWorld/XXXXXXXXX
Created: 2018-12-11 08:39:27.082000+00:00
Last Updated: 2018-12-11 08:57:17.121000+00:00
Capabilities: ['CAPABILITY_IAM']
TerminationProtection: False
Outputs: 
  HelloWorldFunctionIamRole: arn:aws:iam::1234567890:role/GeoLambHelloWorld-HelloWorldFunctionRole-XXXXXXXXX
  HelloWorldApi: https://XXXXXXXXX.execute-api.us-east-1.amazonaws.com/Prod/hello/
  HelloWorldFunction: arn:aws:lambda:us-east-1:1234567890:function:GeoLambHelloWorld-HelloWorldFunction-XXXXXXXXX
Exports: 

Call the lambda function:

$ curl https://XXXXXXXXX.execute-api.us-east-1.amazonaws.com/Prod/hello/

{"geos_version": "2030200", "shapely_geometry": "POINT (1.0000000000000000 2.0000000000000000)"}⏎      

How Python Lambda Layer (Actually) Works

The official documentation is quite obscure on the internals, and only tells how to create a layer when someone has created the "many-linux wheel" packages.

If you want include custom binary in the layer:

• Everything in the lambda function package still goes to /var/task,
• Everything in the lambda layer goes to /opt,
• Python run time will have (besides the usual /var/task stuff`):
  • PATH set to opt/bin
  • LD_LIBRARY_PTH set to opt/lib
  • PYTHON_PATH set to /opt/python and /opt/python/lib/python<version>/site-packages/

So, this means:

• If custom binary dependency is configured to installed in /opt
• And python packages installed in /opt/python/lib/python<version>/site-packages/

We can simply zip-up /opt as a layer, Check Dockerfile for details.