I tried and failed to post a new leaflet document to my PDS. I would hit "Publish this Post!".. and nothing would happen.

The problem was revealed by the nginx logs

54.183.13.48 - - [09/Oct/2025:20:06:23 +0000] "POST /xrpc/com.atproto.repo.uploadBlob HTTP/1.1" 413 176 "-" "node"

See the 413? That's Content Too Large. The post contains an image that's clearly too large.

In /etc/nginx/sites-available/

server {
  client_max_body_size 5M;
  ...
}

This did the trick

184.169.255.223 - - [09/Oct/2025:20:12:21 +0000] "POST /xrpc/com.atproto.repo.uploadBlob HTTP/1.1" 200 141 "-" "node"

It's a shame that leaflet publishing fails silently!