nixos/privacyidea: increase buffer-size of uwsgi from 4096 to 8192

When accessing the Audit log, I get an HTTP 502 when the frontend
requests `/audit` and I get the following error in my `nginx`-log:

    Dec 20 22:12:48 ldap nginx[336]: 2021/12/20 22:12:48 [error] 336#336: *8421 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 10.237.0.1, server: _, request: "GET /audit/?action=**&action_detail=**&administrator=**&client=**&date=**&duration=**&info=**&page=1&page_size=10&policies=**&privacyidea_server=**&realm=**&resolver=**&serial=**&sortorder=desc&startdate=**&success=**&tokentype=**&user=** HTTP/1.1", upstream: "uwsgi://unix:/run/privacyidea/socket:", host: "ldap.ist.nicht-so.sexy", referrer: "https://ldap.ist.nicht-so.sexy/"

This is because of an "invalid request block size"-error according to
`journalctl -u privacyidea.service`:

    Dec 20 22:12:48 ldap uwsgi[10721]: invalid request block size: 4245 (max 4096)...skip

Increasing the buffer to 8192 fixes the problem for me.

1 files changed, 1 insertions, 0 deletions

diff --git a/nixos/modules/services/security/privacyidea.nix b/nixos/modules/services/security/privacyidea.nix
index dacbffec04e..b8e2d9a8b0d 100644
--- a/nixos/modules/services/security/privacyidea.nix
+++ b/nixos/modules/services/security/privacyidea.nix
@@ -204,6 +204,7 @@ in
       systemd.services.privacyidea = let
         piuwsgi = pkgs.writeText "uwsgi.json" (builtins.toJSON {
           uwsgi = {
+            buffer-size = 8192;
             plugins = [ "python3" ];
             pythonpath = "${penv}/${uwsgi.python3.sitePackages}";
             socket = "/run/privacyidea/socket";