Nginx Ingress fails to start with Brotli compression enabled

[mreho]

What happened:

After upgrading from v1.33.5+rke2r1 to v1.33.6+rke2r1, Nginx Ingress version also bumped from v1.12.6-hardened1 to v1.13.4-hardened1.

Since this version, my Brotli compression option (controller.config.enable-brotli = true) in the Helm values overrides of the chart suddenly made the Ingress controller failing to start, with this error :

Error reloading NGINX:
-------------------------------------------------------------------------------
Error: exit status 1
2025/11/22 12:49:58 [emerg] 33#33: dlopen() "/etc/nginx/modules/ngx_http_brotli_filter_module.so" failed (libbrotlienc.so.1: cannot open shared object file: No such file or directory) in /tmp/nginx/nginx-cfg
3944113574:7 nginx: [emerg] dlopen() "/etc/nginx/modules/ngx_http_brotli_filter_module.so" failed (libbrotlienc.so.1: cannot open shared object file: No such file or directory) in /tmp/nginx/nginx-cfg
3944113574:7 nginx: configuration file /tmp/nginx/nginx-cfg3944113574 test failed
-------------------------------------------------------------------------------

What you expected to happen:

It was just working fine before. The ingress controller shouldn't crash.

NGINX Ingress controller version : v1.13.4
Kubernetes version : v1.33.6+rke2r1

Environment:

• Cloud provider or hardware configuration : OpenStack
• OS : Ubuntu 24.04 LTS
• Kernel : 6.11.0-29-generic
• Install tools : Helm
• Containerd version : 2.1.5-k3s1

# helm ls -A | grep -i ingress
rke2-ingress-nginx          	kube-system	2       	2025-11-22 13:54:24.373403504 +0100 CET	deployed	rke2-ingress-nginx-4.13.400         	1.13.4
# helm -n kube-system get values rke2-ingress-nginx
USER-SUPPLIED VALUES:
controller:
  config:
    enable-brotli: "false"
    [REDACTED]
global:
  clusterCIDR: 10.42.0.0/16,fd00:42::/56
  clusterCIDRv4: 10.42.0.0/16
  clusterCIDRv6: fd00:42::/56
  clusterDNS: 10.43.0.10,fd00:43::a
  clusterDomain: cluster.local
  rke2DataDir: /var/lib/rancher/rke2
  serviceCIDR: 10.43.0.0/16,fd00:43::/112
  systemDefaultIngressClass: ingress-nginx

How to reproduce this issue:

Simply enable controller.config.enable-brotli when installing Ingress Controller v1.13.4 using the Helm Chart.

[k8s-ci-robot]

This issue is currently awaiting triage.

If Ingress contributors determines this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

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Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[Gacko]

These versions are not distributed by us. Please file an issue on their end.

[mreho]

@Gacko correct, my bad, v1.13.4-hardened2 fixed this issue from their side