Release FFI binaries for other platforms

[mirogta]

Story:
As a developer who wants to use iotics-identity-go FFI wrapper
I want the FFI binaries pre-built and released
So that I can easily use them for my project in Rust language

We want to publish c-archive (go build -buildmode=c-archive) for the most common platform(s):

• linux/amd64 - DONE in Release FFI binaries for linux/amd64 #37
• linux/arm64
• windows/amd64
• darwin/amd64
• darwin/arm64 (Apple Silicon / M1)

We thought that this should be easily achievable with GoReleaser which supports cross-compilation. But it didn't work, because of a mismatch of the required flags: CGO_ENABLED=1 and -buildmode=c-archive which fail the cross-compilation on some of the platforms.

We could use xgo, a more recent fork of the original xgo

I've tried this command locally which has built all the FFI binaries for almost all the required platforms… except darwin/arm64. It uses "small" docker containers for different OS/arch. For me, it meant >1GB download for each build on a clean system, so not ideal.

go get github.com/karalabe/xgo
xgo -out iotics-identity-ffi-$VERSION --pkg ffi --targets=\*/amd64,\*/arm64 -buildmode=c-archive github.com/Iotic-Labs/iotics-identity-go

Finally, I ran into zig - which seems to be able to cross-compile even for darwin/arm64
More here

Looks like Zig can be used together with GoReleaser (but the below links are for building Zig projects):

• https://openprojectrepo.com/project/knadh-zig-releaser-linux-system-utilities
• https://github.com/knadh/zig-releaser