Compiling Nats Server to WASM with golang and tinygo

[gedw99]

FYI: @neilalexander

I noticed there is some work started to get Nats Server to compile to wasm.

This brings some interesting use cases for both Clients and Servers that I am interested in.

The golang compiler works great. 25 MB is the size of the wasm is big.

The tinygo compiler is complaining about:

tinygo error: server/server.go:34:2: package net/http/pprof is not in std (/Users/apple/Library/Caches/tinygo/goroot-c56cb921522c039d646c5c4f9b8f28598ed4b3910aa8d088c7ff5dd44d7c2cdd/src/net/http/pprof)

I was wondering if the build tags could the adjusted ?

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The Nats team might be interested in https://github.com/tractordev/wanix

It shows off how far you can take golang and wasm in the browser.

[neilalexander]

I think you are likely to run into far bigger problems than net/http/pprof, as TinyGo doesn't support crypto/tls, net/http, crypto/x509 and various other standard library packages that we rely on, and many others that do build don't pass tests properly. Trying to unpick all of this for build tags will be a lot of work. See https://tinygo.org/docs/reference/lang-support/stdlib/ for more info.

Not sure what your use-case is exactly but you may be better trying to optimise the size of the binary from the Go toolchain instead, either with -ldflags="-s -w", using wasm-opt or embedding it into a Go project that is already compiled to WASM such that the standard library, runtime etc are not duplicated across separate .wasm files.

[gedw99]

Regarding Tinygo, I was also wondering about how many more issues I would hit with tinygo, thanks, for clarifying, as I suspected there would be many more too, but was not sure. I think I will go for just golang and gzip the wasm file through Caddy for now.

Regarding golang and WASM compilation permutations, I got 25 MB from all these:

GOOS=js GOARCH=wasm go build -tags osusergo,netgo -ldflags '-extldflags "-static"'

GOOS=js GOARCH=wasm go build -ldflags '-extldflags "-static"'

GOOS=js GOARCH=wasm go build -ldflags '-s -w'

My use case is to have nats server run as a leaf node in a browser in memory.