feat(gatsby-source-filesystem): allow adjusting createRemoteFileNode retry/timeout settings via env vars (#24535)

* (gatsby-source-filesystem) Remote File Node env variables

For developers with awful internet connection (like me), when using createRemoteFileNode, default timeouts of 30000ms are too short. Out of 300 files, it'd fail 1-4 images due to timeout and mess up the build process. 
Thus, it would be useful to overwrite default remote file download settings (retry limits and timeouts) with .env variables. 
For my specific case, just doubling all the values solved all issues.

* Update create-remote-file-node.js

removed ";"s

* updated readme

* update

Co-authored-by: Michal Piechowiak <[email protected]>

Author: webbugt

packages/gatsby-source-filesystem/README.md

@@ -335,3 +335,11 @@ function createMySqlNodes({ name, __sql, idField, keys }, results, ctx) {
 
 module.exports = createMySqlNodes
 ```
+
+## Troubleshooting
+
+In case that due to spotty network, or slow connection, some remote files fail to download. Even after multiple retries and adjusting concurrent downloads, you can adjust timeout and retry settings with these environment variables:
+
+- `STALL_RETRY_LIMIT`, default: `3`
+- `STALL_TIMEOUT`, default: `30000`
+- `CONNECTION_TIMEOUT`, default: `30000`

packages/gatsby-source-filesystem/src/create-remote-file-node.js

@@ -55,10 +55,10 @@ let totalJobs = 0
  * @param  {Reporter} [options.reporter]
  */
 
-const STALL_RETRY_LIMIT = 3
-const STALL_TIMEOUT = 30000
+const STALL_RETRY_LIMIT = process.env.GATSBY_STALL_RETRY_LIMIT || 3
+const STALL_TIMEOUT = process.env.GATSBY_STALL_TIMEOUT || 30000
 
-const CONNECTION_TIMEOUT = 30000
+const CONNECTION_TIMEOUT = process.env.GATSBY_CONNECTION_TIMEOUT || 30000
 
 /********************
  * Queue Management *