Go Component SDK

The Go Component SDK provides a set of packages to simplify the development of WebAssembly components targeting the wasmCloud host runtime.

Writing a wasmCloud Capability Provider? Check out the Go Provider SDK.

Setup

Requires tinygo 0.33 or above.

Import go.wasmcloud.dev/component in your Go module.

go get go.wasmcloud.dev/[email protected]

Import the SDK WIT. In wit/deps.toml:

wasmcloud-component = "https://github.com/wasmCloud/component-sdk-go/archive/v0.0.3.tar.gz"

Run wit-deps to update your wit dependencies.

And in your world definition:

include wasmcloud:component-go/[email protected];

Adapters

net/wasihttp

The wasihttp package provides an implementation of http.Handler backed by wasi:http, as well as a http.RoundTripper backed by wasi:http.

http.Handler

wasihttp.Handle registers an http.Handler to be served at a given path, converting wasi:http requests/responses into standard http.Request and http.ResponseWriter objects.

import (
  "net/http"
  "go.wasmcloud.dev/component/net/wasihttp"
)

func httpServe(w http.ResponseWriter, *r http.Request) {
  w.Write([]byte("Hello, world!"))
}

func init() {
// request will be fulfilled via wasi:http/incoming-handler
  wasihttp.HandleFunc("/", httpServe)
}

http.RoundTripper

import (
  "net/http"
  "go.wasmcloud.dev/component/net/wasihttp"
)

var wasiTransport = &wasihttp.Transport{}
var httpClient = &http.Client{Transport: wasiTransport}

// request will be fulfilled via wasi:http/outgoing-handler
httpClient.Get("http://example.com")

log/wasilog

The wasilog package provides an implementation of slog.Handler backed by wasi:logging.

Sample usage:

import (
  "log/slog"
  "go.wasmcloud.dev/component/log/wasilog"
)

logger := slog.New(wasilog.DefaultOptions().NewHandler())

logger.Info("Hello")
logger.Info("Hello", "planet", "Earth")
logger.Info("Hello", slog.String("planet", "Earth"))

See wasilog.Options for log level & other configuration options.

Community

Similar projects:

• rajatjindal/wasi-go-sdk
• dev-wasm/dev-wasm-go
• Mossaka/hello-wasi-http-tinygo