1 files changed, 146 insertions, 0 deletions
diff --git a/http/server.go b/http/server.go
new file mode 100644
index 0000000..e13bc67
--- /dev/null
+++ b/http/server.go
@@ -0,0 +1,146 @@
+// Package http provides utilities for managing HTTP servers and listeners.
+//
+// It supports opening multiple network listeners from configuration,
+// running multiple HTTP servers concurrently with graceful shutdown,
+// and integrates structured logging with context.
+//
+// This package is designed to be used with context cancellation for concurrency control.
+
+package http
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log/slog"
+	"net"
+	"net/http"
+	"sync"
+	"time"
+
+	"go.sudomsg.com/kit/logging"
+	"golang.org/x/sync/errgroup"
+)
+
+// Listeners is a slice of net.Listener interfaces representing multiple network listeners.
+type Listeners []net.Listener
+
+// CloseAll closes all listeners in the slice.
+// It aggregates all errors returned by individual Close calls using errors.Join.
+//
+// If no errors occur, it returns nil.
+func (ls Listeners) CloseAll() error {
+	var errs []error
+	for _, l := range ls {
+		if err := l.Close(); err != nil {
+			errs = append(errs, err)
+		}
+	}
+	if len(errs) > 0 {
+		return errors.Join(errs...)
+	}
+	return nil
+}
+
+// ServerConfig defines a single network listener configuration.
+//
+// Network is the network type, e.g., "tcp".
+// Address is the socket address, e.g., ":8080".
+type ServerConfig struct {
+	Network string `toml:"network"`
+	Address string `toml:"network"`
+}
+
+// OpenConfigListeners opens network listeners as specified by the provided ServerConfig slice.
+//
+// It attempts to open all listeners concurrently and returns them if all succeed.
+//
+// If any listener fails to open, it closes all previously opened listeners and returns an error.
+//
+// The context controls cancellation of the opening process.
+func OpenConfigListners(ctx context.Context, config []ServerConfig) (Listeners, error) {
+	lns := make(Listeners, 0, len(config))
+	var mu sync.Mutex
+	g, ctx := errgroup.WithContext(ctx)
+	var lc net.ListenConfig
+	for _, cfg := range config {
+		g.Go(func() error {
+			network := cfg.Network
+			if network == "" {
+				network = "tcp"
+			}
+			ln, err := lc.Listen(ctx, network, cfg.Address)
+			if err != nil {
+				return fmt.Errorf("failed to listen on %s %s: %w", network, cfg.Address, err)
+			}
+
+			mu.Lock()
+			lns = append(lns, ln)
+			mu.Unlock()
+			return nil
+		})
+	}
+	if err := g.Wait(); err != nil {
+		_ = lns.CloseAll()
+		return nil, err
+	}
+	return lns, nil
+}
+
+func OpenListeners(ctx context.Context, config []ServerConfig) (Listeners, error) {
+	return OpenConfigListners(ctx, config)
+}
+
+// RunHTTPServers runs HTTP servers concurrently on all provided listeners.
+//
+// The provided handler is used for all servers.
+// Servers respond to context cancellation by performing a graceful shutdown with a timeout of 10 seconds.
+//
+// Logging is performed using the slog.Logger extracted from context.
+// Each server logs startup, shutdown, and errors.
+//
+// This function blocks until all servers have stopped or an error occurs.
+func RunHTTPServers(ctx context.Context, lns Listeners, handler http.Handler) error {
+	g, ctx := errgroup.WithContext(ctx)
+
+	for _, ln := range lns {
+		g.Go(func() error {
+			logger, ctx := logging.With(ctx, "address", ln.Addr)
+
+			srv := &http.Server{
+				Addr:    ln.Addr().String(),
+				Handler: handler,
+				BaseContext: func(l net.Listener) context.Context {
+					return ctx
+				},
+				ErrorLog: slog.NewLogLogger(logger.Handler(), slog.LevelError),
+			}
+
+			logger.Log(ctx, slog.LevelInfo, "HTTP server serving")
+
+			if err := httpServeContext(ctx, srv, ln); err != nil && !errors.Is(err, http.ErrServerClosed) {
+				return fmt.Errorf("HTTP server Serve Error: %w", err)
+			}
+			return nil
+		})
+
+	}
+	return g.Wait()
+}
+
+func httpServeContext(ctx context.Context, srv *http.Server, ln net.Listener) error {
+	logger := logging.FromContext(ctx)
+	go func() {
+		<-ctx.Done()
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		defer cancel()
+
+		err := srv.Shutdown(ctx)
+		if err != nil {
+			logger.Log(ctx, slog.LevelWarn, "HTTP server Shutdown Error", slog.Any("error", err))
+		} else {
+			logger.Log(ctx, slog.LevelInfo, "HTTP Server Shutdown Complete")
+		}
+	}()
+	return srv.Serve(ln)
+}