From 1b1f310167383b48339fd730609b5ec859e79f1a Mon Sep 17 00:00:00 2001
From: Leonardo Rossi <leonardo.rossi@gmail.com>
Date: Thu, 30 Sep 2021 15:31:28 +0200
Subject: [PATCH] adds maxRetriesOn503 option

---
 README.md | 11 +++++++++++
 index.js  |  8 ++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index 83c48f46..077f4466 100644
--- a/README.md
+++ b/README.md
@@ -198,6 +198,17 @@ By default: `['GET', 'HEAD', 'OPTIONS', 'TRACE' ]`
 
 This plugin will always retry on 503 errors, _unless_ `retryMethods` does not contain `GET`.
 
+---
+
+#### `maxRetriesOn503`
+
+This plugin will always retry on `GET` requests that returns 503 errors, _unless_ `retryMethods` does not contain `GET`.
+
+This option set the limit on how many times the plugin should retry the request, specifically for 503 errors.
+
+By Default: 10
+
+
 ---
 
 ### `reply.from(source, [opts])`
diff --git a/index.js b/index.js
index 53eb55f7..5362311a 100644
--- a/index.js
+++ b/index.js
@@ -43,6 +43,7 @@ module.exports = fp(function from (fastify, opts, next) {
     const getUpstream = opts.getUpstream || upstreamNoOp
     const onError = opts.onError || onErrorDefault
     const retriesCount = opts.retriesCount || 0
+    const maxRetriesOn503 = opts.maxRetriesOn503 || 10
 
     if (!source) {
       source = req.url
@@ -119,7 +120,7 @@ module.exports = fp(function from (fastify, opts, next) {
     const contentLength = requestHeaders['content-length']
     let requestImpl
     if (retryMethods.has(req.method) && !contentLength) {
-      requestImpl = createRequestRetry(request, this, retriesCount, retryOnError)
+      requestImpl = createRequestRetry(request, this, retriesCount, retryOnError, maxRetriesOn503)
     } else {
       requestImpl = request
     }
@@ -212,9 +213,8 @@ function isFastifyMultipartRegistered (fastify) {
   return fastify.hasContentTypeParser('multipart') && fastify.hasRequestDecorator('multipart')
 }
 
-function createRequestRetry (requestImpl, reply, retriesCount, retryOnError) {
+function createRequestRetry (requestImpl, reply, retriesCount, retryOnError, maxRetriesOn503) {
   function requestRetry (req, cb) {
-    const MAX_RETRIES_ON_503 = 10
     let retries = 0
 
     function run () {
@@ -228,7 +228,7 @@ function createRequestRetry (requestImpl, reply, retriesCount, retryOnError) {
         if (!reply.sent) {
           // always retry on 503 errors
           if (res && res.statusCode === 503 && req.method === 'GET') {
-            if (retriesCount === 0 && retries < MAX_RETRIES_ON_503) {
+            if (retriesCount === 0 && retries < maxRetriesOn503) {
               // we should stop at some point
               return retry(retryAfter)
             }