Initial functions for http servers

Signed-off-by: Jan Tytgat <jan.tytgat@corelayer.eu>

httpd/httpd.go

@@ -0,0 +1,62 @@
+package httpd
+
+import (
+	"context"
+	"errors"
+	"log/slog"
+	"net/http"
+	"strconv"
+	"time"
+
+	"git.flexabyte.io/flexabyte/go-slogd/slogd"
+)
+
+func RunHttpServer(ctx context.Context, log *slog.Logger, listenAddress string, port int, h http.Handler, shutdownTimeout time.Duration) error {
+	s := &http.Server{
+		Addr:    listenAddress + ":" + strconv.Itoa(port),
+		Handler: h}
+
+	return run(ctx, s, log, shutdownTimeout)
+}
+
+func RunSocketHttpServer(ctx context.Context, log *slog.Logger, socketPath string, h http.Handler, shutdownTimeout time.Duration) error {
+	s := &http.Server{
+		Handler: h}
+
+	return run(ctx, s, log, shutdownTimeout)
+}
+
+func run(ctx context.Context, s *http.Server, log *slog.Logger, shutdownTimeout time.Duration) error {
+	log.LogAttrs(ctx, slogd.LevelTrace, "starting http server", slog.String("listenAddress", s.Addr))
+	idleConnectionsClosed := make(chan struct{})
+
+	runCtx, runCancel := context.WithCancel(ctx)
+	defer runCancel()
+
+	go func(ctx context.Context) {
+		log.LogAttrs(ctx, slogd.LevelTrace, "awaiting shutdown signal for http server", slog.String("listenAddress", s.Addr))
+		<-ctx.Done()
+
+		shutdownCtx, shutdownCancel := context.WithTimeout(context.Background(), shutdownTimeout)
+		defer shutdownCancel()
+
+		log.LogAttrs(shutdownCtx, slogd.LevelTrace, "shutting down http server", slog.String("listenAddress", s.Addr))
+		// We received an interrupt signal, shut down.
+		if err := s.Shutdown(shutdownCtx); err != nil {
+			// Error from closing listeners, or context timeout:
+			log.LogAttrs(ctx, slogd.LevelTrace, "shutting down http server failed", slog.String("listenAddress", s.Addr), slog.Any("error", err))
+		}
+		log.LogAttrs(shutdownCtx, slogd.LevelTrace, "shutting down http server completed", slog.String("listenAddress", s.Addr))
+		close(idleConnectionsClosed)
+	}(runCtx)
+
+	var err error
+	if err = s.ListenAndServe(); !errors.Is(err, http.ErrServerClosed) {
+		// Error starting or closing listener:
+		log.LogAttrs(ctx, slogd.LevelError, "http server start failed", slog.String("error", err.Error()))
+		return err
+	}
+
+	<-idleConnectionsClosed
+	return err
+}