WebDav returning error 413 but server is fine

mfranzil

Hi, this issue refers to report 1085833295.

In the past few weeks my Zotero installation has been giving sync issues with my personal WebDav server. It is a nginx-no-nonsense-webdav instance (https://hub.docker.com/r/dgraziotin/nginx-webdav-nononsense), with a maximum body size of 4G.

Still, I get 413 errors when trying to sync any document from Zotero.

Your WebDAV server returned an HTTP 413 error for a PUT request.

If you receive this message repeatedly, check your WebDAV server settings or contact your WebDAV server administrator.

URL: https://*****:********@*******/zotero/CU6BGWWT.zip

However, no such 413 request is ever even received from the server!

192.168.96.6 - mfranzil [28/Apr/2023:11:50:34 +0200] "GET /zotero/CU6BGWWT.prop HTTP/1.1" 200 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:60.0) Gecko/20100101 Firefox/60.0"

that's the only thing that happens. Even with tcpdump:

11:55:50.841226 IP nginx-proxy.web.45530 > d0cf4fdef1b4.80: Flags [S], seq 3348826653, win 64240, options [mss 1460,sackOK,TS val 2976382772 ecr 0,nop,wscale 7], length 0
11:55:50.841270 IP d0cf4fdef1b4.80 > nginx-proxy.web.45530: Flags [S.], seq 2138229176, ack 3348826654, win 65160, options [mss 1460,sackOK,TS val 3083860376 ecr 2976382772,nop,wscale 7], length 0
11:55:50.841314 IP nginx-proxy.web.45530 > d0cf4fdef1b4.80: Flags [.], ack 1, win 502, options [nop,nop,TS val 2976382772 ecr 3083860376], length 0
11:55:50.841440 IP nginx-proxy.web.45530 > d0cf4fdef1b4.80: Flags [P.], seq 1:615, ack 1, win 502, options [nop,nop,TS val 2976382772 ecr 3083860376], length 614: HTTP: GET /zotero/CU6BGWWT.prop HTTP/1.1
11:55:50.841458 IP d0cf4fdef1b4.80 > nginx-proxy.web.45530: Flags [.], ack 615, win 505, options [nop,nop,TS val 3083860376 ecr 2976382772], length 0
11:55:50.842941 IP d0cf4fdef1b4.80 > nginx-proxy.web.45530: Flags [P.], seq 1:700, ack 615, win 505, options [nop,nop,TS val 3083860377 ecr 2976382772], length 699: HTTP: HTTP/1.1 200 OK
11:55:50.842996 IP nginx-proxy.web.45530 > d0cf4fdef1b4.80: Flags [.], ack 700, win 501, options [nop,nop,TS val 2976382773 ecr 3083860377], length 0
11:55:50.843068 IP d0cf4fdef1b4.80 > nginx-proxy.web.45530: Flags [F.], seq 700, ack 615, win 505, options [nop,nop,TS val 3083860377 ecr 2976382773], length 0
11:55:50.843298 IP nginx-proxy.web.45530 > d0cf4fdef1b4.80: Flags [F.], seq 615, ack 701, win 501, options [nop,nop,TS val 2976382774 ecr 3083860377], length 0
11:55:50.843328 IP d0cf4fdef1b4.80 > nginx-proxy.web.45530: Flags [.], ack 616, win 505, options [nop,nop,TS val 3083860378 ecr 2976382774], length 0

dstillman

The message means what it says. It's an HTTP 413 Content Too Large error from the WebDAV server or something else in between. If there's a reverse proxy, it might be that.

We can look at a Debug ID for the sync attempt, but it's just going to show an HTTP PUT for that ZIP file getting a 413 back. Zotero doesn't make up HTTP errors.

dgraziotin

Hey mfranzil, it just so happens that I use my image with Zotero!

If the nginx server from the running container never receives any request, I would also suspect that it's a reverse proxy that is blocking the request.

Are you using Cloudflare to proxy to the container? Anyhow, feel free to contact me, I'll be happy to help: https://ineed.coffee/contact

mfranzil

Hey, thanks for your support. At the end, it was indeed the reverse proxy whose configuration was too strict, as it would blocks payload over a certain threshold. I solved the issue some time ago, but thank you anyway!