If proxying of the query fails - return 500.

proxy.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"crypto/tls"
+	"fmt"
 	"time"
 
 	fiber "github.com/gofiber/fiber/v2"
@@ -47,6 +48,11 @@ func proxyTheRequest(c *fiber.Ctx) error {
 	}
 	cfg.Logger.Debug("Received proxied response", map[string]interface{}{"path": c.Path(), "response_body": string(c.Response().Body()), "response_code": c.Response().StatusCode()})
 
+	if c.Response().StatusCode() != 200 {
+		cfg.Monitoring.Increment(libpack_monitoring.MetricsFailed, nil)
+		return fmt.Errorf("Received non-200 response from the GraphQL server: %d", c.Response().StatusCode())
+	}
+
 	c.Response().Header.Del(fiber.HeaderServer)
 	return nil
 }