Server crashes with combination of N8N_CUSTOM_EXTENSIONS and NODES_INCLUDE flags

[ponix-net]

Describe the bug
When using custom nodes provided with N8N_CUSTOM_EXTENSIONS flag and specifying it on NODES_INCLUDE list server crashes on start. It also crashes with NODES_INCLUDE flag only if there is non-existing node on the list.

To Reproduce
Steps to reproduce the behavior:

1. Set NODES_INCLUDE flag with invalid node name (or with one from the custom extensions). e.g.:
   export NODES_INCLUDE="[\"CUSTOM.someNode\"]"
2. Run server.
3. Server crashes.

Expected behavior
Server starts and displays only nodes from NODES_INCLUDE array.

Environment:

• OS: Ubuntu Linux 23.04
• n8n Version 1.0.1
• Node.js Version 18.14.2
• Operation mode main

Proposed solution
It is caused by accessing element from known.nodes in LazyPackageDirectoryLoader class without checking if it exists. It can be fixed by adding condition in DirectoryLoader.ts:

374+   if (nodeName in this.known.nodes) {
375        allowedNodes[nodeName] = this.known.nodes[nodeName];
376+   }

With this fix all works as expected: server is not crashing and provides only nodes from NODES_INCLUDE list (both core and custom).

[Joffcom]

Hey @ponix-net,

I have managed to reproduce this one and have created N8N-6706 as our internal ticket to get it fixed.