[pve-devel] Proxmox pveproxy - "to many http header lines" - issues with Cloudflare + latest Chrome

[Victor Hooi]

Hi,

Google Chrome is rolling out some changes to headers (UA-CH - which causes
extra headers to be included), which seems to be unearthing some latent
issues with Proxmox.

Specifically, in the web UI, when using the latest version of Chrome, we're
getting an error message:

Connection failure. Network error or Proxmox VE services not running?


In the pveproxy error logs (i.e. /var/log/syslog), I see:

Jul  1 15:45:22 examplemtv-vm01 pveproxy[49572]: to many http header lines
> Jul  1 15:45:27 examplemtv-vm01 pveproxy[49572]: problem with client
> 127.0.0.1; Connection timed out


>From an old PVE/HTTPServer.pm, somebody mentioned it might be this line:

https://github.com/proxmox/pve-manager/blob/master/PVE/HTTPServer.pm#L37

(I'm having trouble using the new git.proxmox.com interface to search the
code).

Specifically the line:

my $limit_max_headers = 30;


which seems to limit the header count to 30.

Anyhow, I searched my local Proxmox system, and it seems to be in
APIServer/AnyEvent.pm now.

My assumption is that this issue is unearthed, due to extra headers the
Cloudflare proxy adds on, along with extra headers than the new Chrome
UA-CH feature adds, causing us to hit that 30 header limit.

I did edit the PVE/APIServer/AnyEvent.pm file myself on a local Proxmox
server, and hand-edited it to

my $limit_max_headers = 100;


which resolves the issue.

Is there a specific reason the header limit is set to 30?

If so, would it be possible to file a bug request to amend the limit?

Thanks,
Victor