platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/bootstrap/server_runner.go

@@ -0,0 +1,54 @@
+package bootstrap
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+type Config struct {
+	Addr              string
+	ReadHeaderTimeout time.Duration
+	RegisterRoutes    func(mux *http.ServeMux)
+	WrapHandler       func(next http.Handler) http.Handler
+	StartWatchers     func(ctx context.Context)
+}
+
+func Run(ctx context.Context, cfg Config) error {
+	if cfg.RegisterRoutes == nil {
+		return fmt.Errorf("register routes callback is required")
+	}
+	if cfg.Addr == "" {
+		return fmt.Errorf("addr is required")
+	}
+
+	readHeaderTimeout := cfg.ReadHeaderTimeout
+	if readHeaderTimeout <= 0 {
+		readHeaderTimeout = 5 * time.Second
+	}
+
+	mux := http.NewServeMux()
+	cfg.RegisterRoutes(mux)
+
+	handler := http.Handler(mux)
+	if cfg.WrapHandler != nil {
+		handler = cfg.WrapHandler(handler)
+	}
+
+	srv := &http.Server{
+		Addr:              cfg.Addr,
+		Handler:           handler,
+		ReadHeaderTimeout: readHeaderTimeout,
+	}
+
+	if cfg.StartWatchers != nil {
+		go cfg.StartWatchers(ctx)
+	}
+
+	if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+		return err
+	}
+	return nil
+}