micro-containers: WASI preview1 variant — JSON to stdout (no net/http in wasip1)

main.go

// WASI preview1 target — compiled with GOOS=wasip1 GOARCH=wasm.
// net/http is not available in wasip1; this demonstrates env access,
// stdout, and runtime introspection inside a WASM container.
// The wasi-http proposal (https://github.com/WebAssembly/wasi-http)
// will bring full HTTP support to WASI in a future Go release.
package main

import (
	"encoding/json"
	"fmt"
	"os"
	"runtime"
)

func main() {
	name := "wasm"
	if v := os.Getenv("RUNTIME_NAME"); v != "" {
		name = v
	}

	payload := map[string]string{
		"status":     "ok",
		"runtime":    name,
		"go_version": runtime.Version(),
		"goos":       runtime.GOOS,
		"goarch":     runtime.GOARCH,
	}

	enc := json.NewEncoder(os.Stdout)
	enc.SetIndent("", "  ")
	if err := enc.Encode(payload); err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}