Compress runtime/modules to reduce deployment package unzipped size

[sean-r-williams]

AWS Lambda limits ZIP deployment packages to 250 MB on-disk. The Linux PowerShell release builds are ~170 MB in the current release, which takes up ~70% of that cap. (Community members' attempts at producing "slim" PowerShell containers only reduce sizes by ~30MB, which isn't a ton in broader context.)

Pure PowerShell script modules are generally quite small, but compiled CLR module assemblies or autogenerated modules (e.g. Microsoft.Graph.*, Az.*, AWS.Tools.*) can get very large.

The current architecture only allows for ~80MB of module dependencies - AWS.Tools.S3 and Microsoft.Graph.Users (with respective dependencies) breaches the 250MB cap.

Compressing the PowerShell runtime itself would:

• Free up >100MB of deployment package size (172MB vs 66 MB)
• Unblock build artifact verification (PowerShell publishes SHAs of release artifacts)

Supporting compressed module dependencies (e.g. /opt/modules-packed.zip or /opt/modules-packed/*.nupkg gets unpacked to /tmp/modules-unpacked and added to PSModulePath) could help the situation as well.

[sean-r-williams]

FWIW, Packed modules would be ostensibly easier to support as there's no runtime changes required (plus PSResourceGet can handle installing a directory full of nupkgs on its own), but slimming down the runtime proper would be a big win here.

[sean-r-williams]

#38 (currently a draft) handles packed module support, but support for compressing the runtime will need more expertise.

It seems like provided.al2023 has limited support for tar (though libarchive is mentioned, which should have BSD tar?). Not currently clear if there's a better way to consume tar.gz files with what's in-box on a Lambda runner container.