From 7ab5aa052233607e201faf883a9edc9e3544924b Mon Sep 17 00:00:00 2001
From: Matt Kane <matt@gatsbyjs.com>
Date: Fri, 21 May 2021 12:53:14 +0100
Subject: [PATCH] fix: catch oversize image response

---
 src/lib/templates/imageFunction.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/lib/templates/imageFunction.js b/src/lib/templates/imageFunction.js
index 7be53b6251..6b39bfb186 100644
--- a/src/lib/templates/imageFunction.js
+++ b/src/lib/templates/imageFunction.js
@@ -4,6 +4,9 @@ const fetch = require('node-fetch')
 const imageType = require('image-type')
 const isSvg = require('is-svg')
 
+// 6MB is hard max Lambda response size
+const MAX_RESPONSE_SIZE = 6291456
+
 function getImageType(buffer) {
   const type = imageType(buffer)
   if (type) {
@@ -101,6 +104,13 @@ const handler = async (event) => {
     .resize(width)
     .toBuffer({ resolveWithObject: true })
 
+  if (imageBuffer.length > MAX_RESPONSE_SIZE) {
+    return {
+      statusCode: 400,
+      body: 'Requested image is too large. Maximum size is 6MB.',
+    }
+  }
+
   return {
     statusCode: 200,
     headers: {