feat: initial commit

site/handler.go

@@ -0,0 +1,61 @@
+package site
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+	"sync"
+)
+
+type counter struct {
+	hits map[string]int
+	mu   sync.Mutex
+}
+
+type handler struct {
+	logger          *slog.Logger
+	requestsCounter *counter
+}
+
+func newHandler(logger *slog.Logger) *handler {
+	return &handler{
+		logger:          logger,
+		requestsCounter: &counter{hits: make(map[string]int)},
+	}
+}
+
+func (h *handler) LoggingMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		h.logger.Debug("Received request", "path", r.URL.Path)
+		next.ServeHTTP(w, r)
+		h.logger.Debug("Finished Request", "path", r.URL.Path)
+	})
+}
+
+func (h *handler) RequestsCounterMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		h.requestsCounter.mu.Lock()
+		h.requestsCounter.hits[r.URL.Path] += 1
+		h.requestsCounter.mu.Unlock()
+		next.ServeHTTP(w, r)
+	})
+}
+
+func (h *handler) Ping(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "Pong")
+}
+
+func (h *handler) Metrics(w http.ResponseWriter, r *http.Request) {
+	h.requestsCounter.mu.Lock()
+	defer h.requestsCounter.mu.Unlock()
+	for path, hits := range h.requestsCounter.hits {
+		fmt.Fprintf(w, "http_requests_total{handler=\"%s\"} %d\n", path, hits)
+	}
+}
+func (h *handler) Healthz(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintln(w, "Ok")
+}
+
+func (h *handler) NotFound(w http.ResponseWriter, r *http.Request) {
+	http.Error(w, "Page Not Found", http.StatusNotFound)
+}

site/router.go

@@ -0,0 +1,32 @@
+package site
+
+import "net/http"
+
+func middlewares(h *handler, next http.Handler) http.Handler {
+	return h.LoggingMiddleware(h.RequestsCounterMiddleware(next))
+}
+
+func createRoutes(h *handler) map[string]http.Handler {
+	routes := map[string]http.Handler{
+		"/ping":    middlewares(h, http.HandlerFunc(h.Ping)),
+		"/metrics": middlewares(h, http.HandlerFunc(h.Metrics)),
+		"/healthz": middlewares(h, http.HandlerFunc(h.Healthz)),
+	}
+	return routes
+}
+
+func newRouter(handler *handler) http.Handler {
+	mux := http.NewServeMux()
+	for pattern, handler := range createRoutes(handler) {
+		mux.Handle(pattern, handler)
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if h, pattern := mux.Handler(r); pattern != "" {
+			h.ServeHTTP(w, r)
+		} else {
+			middlewares(handler, http.HandlerFunc(handler.NotFound)).ServeHTTP(w, r)
+			http.Error(w, "Boo", http.StatusNotFound)
+		}
+	})
+}

site/site.go

@@ -0,0 +1,26 @@
+package site
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+)
+
+type Config struct {
+	Logger *slog.Logger
+	Port   int
+}
+
+func NewConfig(logLevel slog.Level, port int) Config {
+	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelDebug}))
+	return Config{
+		Logger: logger,
+		Port:   port,
+	}
+}
+
+func Run(c Config) error {
+	h := newHandler(c.Logger)
+	return http.ListenAndServe(fmt.Sprintf(":%d", c.Port), newRouter(h))
+}