feat: OpenTelemetry tracing and metrics (#262) (#495)

Co-authored-by: ItalyPaleAle <43508+ItalyPaleAle@users.noreply.github.com>

backend/internal/bootstrap/router_bootstrap.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/gin-gonic/gin"
+	"go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin"
 	"golang.org/x/time/rate"
 	"gorm.io/gorm"
 
@@ -44,6 +45,10 @@ func initRouterInternal(db *gorm.DB, svc *services) (utils.Service, error) {
 	r := gin.Default()
 	r.Use(gin.Logger())
 
+	if common.EnvConfig.TracingEnabled {
+		r.Use(otelgin.Middleware("pocket-id-backend"))
+	}
+
 	rateLimitMiddleware := middleware.NewRateLimitMiddleware()
 
 	// Setup global middleware