isle/go/cmd/entrypoint/daemon_util.go

package main

import (
	"context"
	"errors"
	"fmt"
	"isle/daemon"
	"isle/daemon/jsonrpc2"
	"net"
	"net/http"
	"os"

	"dev.mediocregopher.com/mediocre-go-lib.git/mctx"
	"dev.mediocregopher.com/mediocre-go-lib.git/mlog"
)

const daemonHTTPRPCPath = "/rpc/v0.json"

func newHTTPServer(
	ctx context.Context, logger *mlog.Logger, rpc *daemon.RPC,
) (
	*http.Server, error,
) {
	socketPath := daemon.HTTPSocketPath()
	l, err := net.Listen("unix", socketPath)
	if err != nil {
		return nil, fmt.Errorf(
			"listening on socket %q: %w", socketPath, err,
		)
	}

	if err := os.Chmod(socketPath, 0660); err != nil {
		return nil, fmt.Errorf(
			"setting permissions of %q to 0660: %w", socketPath, err,
		)
	}

	ctx = mctx.Annotate(ctx, "httpAddr", l.Addr().String())
	logger.Info(ctx, "HTTP server socket created")

	rpcHandler := jsonrpc2.Chain(
		jsonrpc2.NewMLogMiddleware(logger.WithNamespace("rpc")),
		jsonrpc2.ExposeServerSideErrorsMiddleware,
	)(
		jsonrpc2.NewDispatchHandler(&rpc),
	)

	httpMux := http.NewServeMux()
	httpMux.Handle(daemonHTTPRPCPath, jsonrpc2.NewHTTPHandler(rpcHandler))

	srv := &http.Server{Handler: httpMux}

	go func() {
		if err := srv.Serve(l); !errors.Is(err, http.ErrServerClosed) {
			logger.Fatal(ctx, "HTTP server unexpectedly shut down", err)
		}
	}()

	return srv, nil
}