implemented observability

internal/observability/health.go

@@ -0,0 +1,52 @@
+package observability
+
+import (
+	"fmt"
+
+	"xorm.io/xorm"
+
+	"github.com/forgeo/forgebucket/internal/events"
+)
+
+const Version = "0.8.0"
+
+// HealthStatus is the response shape for GET /health.
+type HealthStatus struct {
+	Status  string            `json:"status"`  // "healthy" | "degraded"
+	Checks  map[string]string `json:"checks"`  // dependency name → "ok" | error message
+	Version string            `json:"version"`
+}
+
+// Check pings each critical dependency and returns a HealthStatus.
+// HTTP status should be 200 when Status=="healthy", 503 when "degraded".
+func Check(db *xorm.Engine, bus events.EventBus) HealthStatus {
+	checks := make(map[string]string, 2)
+
+	// Database — attempt a lightweight ping.
+	if err := db.Ping(); err != nil {
+		checks["database"] = fmt.Sprintf("error: %v", err)
+	} else {
+		checks["database"] = "ok"
+	}
+
+	// NATS — use the Healthy() method added in Phase 3E.
+	if bus.Healthy() {
+		checks["nats"] = "ok"
+	} else {
+		checks["nats"] = "disconnected"
+	}
+
+	overall := "healthy"
+	for _, v := range checks {
+		if v != "ok" {
+			overall = "degraded"
+			break
+		}
+	}
+
+	return HealthStatus{
+		Status:  overall,
+		Checks:  checks,
+		Version: Version,
+	}
+}