AWS Lambda Layer for Python PyFilesystem2 module.

Maybe it seems weird to add a Layer just to do "filesystem" work. Sure, Lambda are small discrete units of work; surely they don't require a complex filesystem handler for Python?

Have you ever grown tired of Lambda's 512 MB /tmp space? Ever hit that limit? Ever wonder how you might get even just a smidge more room?

Did you notice that PyFilesystem2 does mem-fs? S3-fs?

Maybe it won't work. Maybe AWS will notice and shut it down. But I say we try.

1. Confirm the build directory is clean.

   $ ls -1 build
   build-pyfs2.sh

2. Then execute the docker public.ecr.aws/lambda/python images to run the build script.

   docker run --rm -v `pwd`/build:/var/task -it --entrypoint /bin/bash public.ecr.aws/lambda/python:3.6 ./build-pyfs2.sh
   docker run --rm -v `pwd`/build:/var/task -it --entrypoint /bin/bash public.ecr.aws/lambda/python:3.7 ./build-pyfs2.sh
   docker run --rm -v `pwd`/build:/var/task -it --entrypoint /bin/bash public.ecr.aws/lambda/python:3.8 ./build-pyfs2.sh
   docker run --rm -v `pwd`/build:/var/task -it --entrypoint /bin/bash public.ecr.aws/lambda/python:3.9 ./build-pyfs2.sh

Once the layer zip files are created, you can deploy them to your AWS account with the following command:

aws lambda publish-layer-version --layer-name "pyfilesystem2-python36" --description "PyFilesystem2 Module for Python 3.6 Runtime" --license-info "BSD-2-Clause" --compatible-runtimes "python3.6" --zip-file "fileb://build/pyfilesystem2-python3.6.zip"
aws lambda publish-layer-version --layer-name "pyfilesystem2-python37" --description "PyFilesystem2 Module for Python 3.7 Runtime" --license-info "BSD-2-Clause" --compatible-runtimes "python3.7" --zip-file "fileb://build/pyfilesystem2-python3.7.zip"
aws lambda publish-layer-version --layer-name "pyfilesystem2-python38" --description "PyFilesystem2 Module for Python 3.8 Runtime" --license-info "BSD-2-Clause" --compatible-runtimes "python3.8" --zip-file "fileb://build/pyfilesystem2-python3.8.zip"
aws lambda publish-layer-version --layer-name "pyfilesystem2-python39" --description "PyFilesystem2 Module for Python 3.9 Runtime" --license-info "BSD-2-Clause" --compatible-runtimes "python3.9" --zip-file "fileb://build/pyfilesystem2-python3.9.zip"