Add rate limiting

internal/server/health.go

@@ -0,0 +1,87 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"time"
+)
+
+// HealthStatus represents the health check response.
+type HealthStatus struct {
+	Status    string            `json:"status"`
+	Timestamp int64             `json:"timestamp"`
+	Checks    map[string]string `json:"checks,omitempty"`
+}
+
+// handleHealth returns a basic health check endpoint.
+// This is suitable for Kubernetes liveness probes.
+func (s *GatewayServer) handleHealth(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	status := HealthStatus{
+		Status:    "healthy",
+		Timestamp: time.Now().Unix(),
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	_ = json.NewEncoder(w).Encode(status)
+}
+
+// handleReady returns a readiness check that verifies dependencies.
+// This is suitable for Kubernetes readiness probes and load balancer health checks.
+func (s *GatewayServer) handleReady(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	checks := make(map[string]string)
+	allHealthy := true
+
+	// Check conversation store connectivity
+	ctx, cancel := context.WithTimeout(r.Context(), 2*time.Second)
+	defer cancel()
+
+	// Test conversation store by attempting a simple operation
+	testID := "health_check_test"
+	_, err := s.convs.Get(testID)
+	if err != nil {
+		checks["conversation_store"] = "unhealthy: " + err.Error()
+		allHealthy = false
+	} else {
+		checks["conversation_store"] = "healthy"
+	}
+
+	// Check if at least one provider is configured
+	models := s.registry.Models()
+	if len(models) == 0 {
+		checks["providers"] = "unhealthy: no providers configured"
+		allHealthy = false
+	} else {
+		checks["providers"] = "healthy"
+	}
+
+	_ = ctx // Use context if needed
+
+	status := HealthStatus{
+		Timestamp: time.Now().Unix(),
+		Checks:    checks,
+	}
+
+	if allHealthy {
+		status.Status = "ready"
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusOK)
+	} else {
+		status.Status = "not_ready"
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusServiceUnavailable)
+	}
+
+	_ = json.NewEncoder(w).Encode(status)
+}