Initial commit.

internal/services/core/httpserver.go

@@ -0,0 +1,23 @@
+package core
+
+import (
+	"errors"
+	"net/http"
+)
+
+// ServiceNameHTTPServer is a name for HTTP server service.
+const ServiceNameHTTPServer = "core/http_server"
+
+// ErrHTTPServerIsInvalid appears when HTTP server service implementation is invalid.
+var ErrHTTPServerIsInvalid = errors.New("HTTP server service implementation is invalid")
+
+// HTTPServer is an interface for HTTP server service.
+type HTTPServer interface {
+	// RegisterHandler registers HTTP handler.
+	RegisterHandler(method, path string, handler http.HandlerFunc)
+	// RegisterMiddleware registers HTTP server middlewares.
+	RegisterMiddleware(middleware HTTPMiddlewareFunc)
+}
+
+// HTTPMiddlewareFunc is a function that acts as middleware for HTTP requests.
+type HTTPMiddlewareFunc func(fn http.HandlerFunc) http.HandlerFunc

internal/services/core/httpserver/default_handler.go

@@ -0,0 +1,8 @@
+package httpserver
+
+import "net/http"
+
+func (h *httpServer) defaultHandler(w http.ResponseWriter, _ *http.Request) {
+	w.WriteHeader(http.StatusNotFound)
+	_, _ = w.Write([]byte("Unknown path."))
+}

internal/services/core/httpserver/httpserver.go

@@ -0,0 +1,84 @@
+package httpserver
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+	"net/http"
+
+	"go.dev.pztrn.name/vikunja-notifier/internal/application"
+	"go.dev.pztrn.name/vikunja-notifier/internal/services/core"
+)
+
+var (
+	_ = core.HTTPServer(&httpServer{})
+
+	errHTTPServer = errors.New("HTTP server core service")
+)
+
+type httpServer struct {
+	app         *application.Application
+	logger      *slog.Logger
+	httpSrv     *http.Server
+	httpMux     *http.ServeMux
+	middlewares []core.HTTPMiddlewareFunc
+}
+
+// Initialize initializes service.
+func Initialize(app *application.Application) error {
+	httpSrv := &httpServer{
+		app: app,
+	}
+
+	if err := app.RegisterService(httpSrv); err != nil {
+		return fmt.Errorf("%w: %w", errHTTPServer, err)
+	}
+
+	return nil
+}
+
+func (h *httpServer) Configure() error {
+	h.logger.Debug("Configuring service...")
+
+	if err := h.configureHTTPServer(); err != nil {
+		return fmt.Errorf("configure: %w", err)
+	}
+
+	return nil
+}
+
+func (h *httpServer) ConnectDependencies() error {
+	return nil
+}
+
+func (h *httpServer) Initialize() error {
+	h.logger = h.app.NewLogger("service", core.ServiceNameHTTPServer)
+
+	h.logger.Info("Initializing...")
+
+	h.middlewares = make([]core.HTTPMiddlewareFunc, 0)
+
+	h.RegisterMiddleware(h.requestLoggingMiddleware)
+
+	return nil
+}
+
+func (h *httpServer) Name() string {
+	return core.ServiceNameHTTPServer
+}
+
+func (h *httpServer) LaunchStartupTasks() error {
+	h.logger.Debug("Launching startup tasks...")
+
+	go h.startHTTPServer()
+
+	return nil
+}
+
+func (h *httpServer) Shutdown() error {
+	if err := h.stopHTTPServer(); err != nil {
+		return fmt.Errorf("%w: Shutdown: %w", errHTTPServer, err)
+	}
+
+	return nil
+}

internal/services/core/httpserver/request_logger.go

@@ -0,0 +1,24 @@
+package httpserver
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+)
+
+func (h *httpServer) requestLoggingMiddleware(fn http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		startTime := time.Now()
+
+		fn(w, r)
+
+		h.logger.Info(
+			"HTTP request.",
+			"remote_addr", r.RemoteAddr,
+			"user_agent", r.UserAgent(),
+			"host", r.Host,
+			"path", fmt.Sprintf("%s %s", r.Method, r.RequestURI),
+			"duration", time.Since(startTime),
+		)
+	}
+}

internal/services/core/httpserver/server.go

@@ -0,0 +1,81 @@
+package httpserver
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"net/http"
+	"os"
+	"time"
+
+	"go.dev.pztrn.name/vikunja-notifier/internal/services/core"
+)
+
+const httpServerAddrEnvVar = "VN_HTTP_ADDRESS"
+
+var (
+	errHTTPServerAddrInvalid = errors.New("VN_HTTP_ADDRESS environment variable contains invalid address to " +
+		"listen, should be 'host:port'")
+	errHTTPServerAddrNotFound = errors.New("VN_HTTP_ADDRESS environment variable empty")
+)
+
+func (h *httpServer) configureHTTPServer() error {
+	httpSrvAddr, found := os.LookupEnv(httpServerAddrEnvVar)
+	if !found {
+		return fmt.Errorf("configure HTTP server: get address from environment variable: %w", errHTTPServerAddrNotFound)
+	}
+
+	host, port, err := net.SplitHostPort(httpSrvAddr)
+	if err != nil {
+		return fmt.Errorf("configure HTTP server: validate HTTP server address: %w", err)
+	}
+
+	if httpSrvAddr != host+":"+port {
+		return fmt.Errorf("configure HTTP server: validate HTTP server address: %w", errHTTPServerAddrInvalid)
+	}
+
+	h.httpMux = new(http.ServeMux)
+
+	// Default catch-all handler.
+	h.RegisterHandler("", "/", h.defaultHandler)
+
+	h.httpSrv = &http.Server{
+		Addr:              httpSrvAddr,
+		Handler:           h.httpMux,
+		ReadHeaderTimeout: time.Second * 3,
+	}
+
+	return nil
+}
+
+func (h *httpServer) RegisterHandler(method, path string, handler http.HandlerFunc) {
+	h.httpMux.HandleFunc(fmt.Sprintf("%s %s", method, path), func(w http.ResponseWriter, r *http.Request) {
+		for i := len(h.middlewares) - 1; i >= 0; i-- {
+			handler = h.middlewares[i](handler)
+		}
+
+		handler(w, r)
+	})
+}
+
+func (h *httpServer) RegisterMiddleware(middleware core.HTTPMiddlewareFunc) {
+	h.middlewares = append(h.middlewares, middleware)
+}
+
+func (h *httpServer) startHTTPServer() {
+	h.logger.Info("Starting listening for HTTP requests.", "address", h.httpSrv.Addr)
+
+	if err := h.httpSrv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+		h.logger.Warn("Error when listening to ", "error", err.Error())
+	}
+}
+
+func (h *httpServer) stopHTTPServer() error {
+	h.logger.Info("Stopping HTTP server...")
+
+	if err := h.httpSrv.Shutdown(h.app.ContextWithTimeout(time.Second * 3)); err != nil {
+		return fmt.Errorf("stopping HTTP server: %w", err)
+	}
+
+	return nil
+}