Troubleshooting the 502 Error


I just ran into a major error that took my whole instance down. here’s a lil postmortem. I tried to install a community node that had package dependencies – n8n-nodes-pdf2image

I was just banging thru stuff and figured I’d pop out to the server and install the poppler-utils package after the node. That was a MASSIVE mistake. The npm page for the node does indicate the dependencies, but doesn’t indicate an order of operations.

Out on the server, I tried to update first. At this point, I had no idea what was wrong. Updated, but the entire instance was still reporting 502

Next, I checked the status of the running processes

\> docker ps -a

That showed me the server was running, but the n8n instance was stuck in a reboot loop. That started me thinking that the node without its dependencies was the issue.

Next I tried installing the dependency via Dockerfile. Still 502.

Finally, I removed the node. It was a bit of a slag to find the dir.

\> docker volume ls
DRIVER VOLUME NAME
local n8n_data
local …

\> docker run --rm -v n8n_data:/n8n_data ubuntu:latest bash -c “ls -lA /n8n_data”
d——— 3 ubuntu ubuntu 4096 Oct 25 00:02 nodes

lather, rinse, repeat until I found the modules dir. once I had the right path, I used this command to nuke the bad node

\> docker run --rm -v n8n_data:/n8n_data ubuntu:latest bash -c “rm -rf /n8n_data/nodes/node_modules/n8n-nodes-pdf2image”

after pulling out the Dockerfile ref in my config,

\> docker compose up -d

put us back in action. be safe out there.