chore: only log warning if media type is not supported (415) (#6847)

packages/beacon-node/src/api/rest/base.ts

@@ -1,5 +1,5 @@
 import {parse as parseQueryString} from "qs";
-import {FastifyInstance, FastifyRequest, fastify} from "fastify";
+import {FastifyInstance, FastifyRequest, fastify, errorCodes} from "fastify";
 import {fastifyCors} from "@fastify/cors";
 import bearerAuthPlugin from "@fastify/bearer-auth";
 import {ErrorAborted, Gauge, Histogram, Logger} from "@lodestar/utils";
@@ -28,6 +28,11 @@ export type RestApiServerMetrics = SocketMetrics & {
   errors: Gauge<{operationId: string}>;
 };
 
+/**
+ * Error code used by Fastify if media type is not supported (415)
+ */
+const INVALID_MEDIA_TYPE_CODE = errorCodes.FST_ERR_CTP_INVALID_MEDIA_TYPE().code;
+
 /**
  * REST API powered by `fastify` server.
  */
@@ -107,7 +112,7 @@ export class RestApiServer {
 
       const operationId = getOperationId(req);
 
-      if (err instanceof ApiError) {
+      if (err instanceof ApiError || err.code === INVALID_MEDIA_TYPE_CODE) {
         this.logger.warn(`Req ${req.id} ${operationId} failed`, {reason: err.message});
       } else {
         this.logger.error(`Req ${req.id} ${operationId} error`, {}, err);