Add basic webserver skeleton with healthcheck

internal/handlers/handlers.go

@@ -0,0 +1,60 @@
+// Package handlers provides HTTP request handlers.
+package handlers
+
+import (
+	"context"
+	"encoding/json"
+	"log/slog"
+	"net/http"
+
+	"go.uber.org/fx"
+	"sneak.berlin/go/pixa/internal/healthcheck"
+	"sneak.berlin/go/pixa/internal/logger"
+)
+
+// HandlersParams defines dependencies for Handlers.
+type HandlersParams struct {
+	fx.In
+	Logger      *logger.Logger
+	Healthcheck *healthcheck.Healthcheck
+}
+
+// Handlers provides HTTP request handlers.
+type Handlers struct {
+	log *slog.Logger
+	hc  *healthcheck.Healthcheck
+}
+
+// New creates a new Handlers instance.
+func New(lc fx.Lifecycle, params HandlersParams) (*Handlers, error) {
+	s := &Handlers{
+		log: params.Logger.Get(),
+		hc:  params.Healthcheck,
+	}
+
+	lc.Append(fx.Hook{
+		OnStart: func(ctx context.Context) error {
+			return nil
+		},
+	})
+
+	return s, nil
+}
+
+func (s *Handlers) respondJSON(w http.ResponseWriter, data interface{}, status int) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	if data != nil {
+		err := json.NewEncoder(w).Encode(data)
+		if err != nil {
+			s.log.Error("json encode error", "error", err)
+		}
+	}
+}
+
+func (s *Handlers) respondError(w http.ResponseWriter, code string, message string, status int) {
+	s.respondJSON(w, map[string]string{
+		"error":   code,
+		"message": message,
+	}, status)
+}

internal/handlers/healthcheck.go

@@ -0,0 +1,12 @@
+package handlers
+
+import (
+	"net/http"
+)
+
+func (s *Handlers) HandleHealthCheck() http.HandlerFunc {
+	return func(w http.ResponseWriter, _ *http.Request) {
+		resp := s.hc.Healthcheck()
+		s.respondJSON(w, resp, http.StatusOK)
+	}
+}

internal/handlers/image.go

@@ -0,0 +1,28 @@
+package handlers
+
+import (
+	"net/http"
+)
+
+// HandleImage handles the main image proxy route:
+// /v1/image/<host>/<path>/<width>x<height>.<format>
+func (s *Handlers) HandleImage() http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
+		// FIXME: Implement image proxy handler
+		// - Parse URL to extract host, path, size, format
+		// - Validate signature and expiration
+		// - Check source host whitelist
+		// - Fetch from upstream (with SSRF protection)
+		// - Process image (resize, convert format)
+		// - Cache and serve result
+		panic("unimplemented")
+	}
+}
+
+// HandleRobotsTxt serves robots.txt to prevent search engine crawling
+func (s *Handlers) HandleRobotsTxt() http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
+		// FIXME: Implement robots.txt handler
+		panic("unimplemented")
+	}
+}