NGINX App Protect WAF Troubleshooting Guide

Learn about the NGINX App Protect WAF Troubleshooting Guide.

Overview

This Troubleshooting Guide is intended to provide guidance to customers in the detection and correction of programming issues in NGINX App Protect. It may also be useful to IT in resolving any installation or configuration problems.

Refer to the below table for any NGINX App Protect WAF installation or configuration known problems.

Resolving Known Problems

Configuration

{
    "policy": {
    ...
    }
}

SELinux

In some operating systems, security mechanisms like SELinux or AppArmor are enabled by default, potentially blocking necessary file access for the nginx process and waf-config-mgr and waf-enforcer containers. To ensure NGINX App Protect WAF operates smoothly without compromising security, consider setting up a custom SELinux policy or AppArmor profile. For short-term troubleshooting, you may use permissive (SELinux) or complain (AppArmor) mode to avoid these restrictions, but keep in mind that this lowers security and isn’t advised for prolonged use.

For more information about how to use NGINX Plus with SELinux - check our blog.

Opening a Support Ticket

In order to open a support ticket, collect the troubleshooting information in one directory, create a tarball and send it to your customer support engineer:

1. For Docker compose deployment, run the following command to collect logs:

   sudo docker compose logs > docker_compose_logs.txt
   

   Alternatively, if a centralized logging system like the ELK stack is utilized, retrieve the logs in CSV format, docker_compose_logs.csv.

2. For Kubernetes deployment:

   Replace default in code snippets below with the name of your namespace.

   Locate the deployment and list all pods:

   kubectl get pods -n default
   

   Use the following script to collect logs from all pods:

   #!/bin/bash
   
   set -x
   
   # Define the namespace variable
   NAMESPACE="default"
   
   # Define a directory to store log files
   log_dir="k8s_logs_$(date +%Y%m%d_%H%M%S)"
   mkdir -p "$log_dir"
   
   # Loop through all pods and containers, saving logs to the defined directory
   for pod in $(kubectl get pods -n $NAMESPACE -o=name | sed 's|pod/||g'); do
       for container in $(kubectl get pod/$pod -n $NAMESPACE -o=jsonpath='{.spec.containers[*].name}'); do
           kubectl logs $pod -c $container -n $NAMESPACE > "${log_dir}/${pod}_${container}_logs.txt"
       done
   done
   
   echo "Logs collected and archived in ${log_dir}.tar.gz"
   

   This script iterates over each pod in your namespace, identifies each container within those pods, and then saves the logs of each container into separate files. These files are named after the respective pod and container and are stored in a directory named k8s_logs_<timestamp>.

3. If NGINX is directly installed on the host machine:

   • For CentOS / RHEL / Amazon Linux / Oracle Linux:

   rpm -qa nginx* app-protect* > package_versions.txt
   

   • For Debian / Ubuntu:

   apt list --installed | grep -E 'nginx|app-protect' > package_versions.txt
   

   • For Alpine Linux:

   apk info -vv | grep -E 'nginx|app-protect' > package_versions.txt
   

   • Get OS information via:

   cat /etc/os-release > system_version.txt && uname -r >> system_version.txt && cat /proc/version >> system_version.txt
   

   • Add nginx logs from /var/log/nginx/

4. Add all policies and log file configuration (JSON and bundle files).

5. Add all nginx configuration including all references such as /etc/nginx/nginx.conf

6. At the same direcotory, run the following command to create the tarball file:

   tar cvfz logs.tgz .
   

7. Attach logs.tgz to support ticket.