Editing Troubleshooting:Nginx Troubleshooting

'''Note:''' Public HTTPS on this VPS is handled by '''Caddy''' (<code>/etc/caddy/Caddyfile</code>). Use [[System:Service Management]] and <code>journalctl -u caddy</code> for edge proxy issues.

This guide covers '''legacy host Nginx''' site files and the '''WebApp stack's internal Nginx''' container. Host Nginx is not the active edge proxy for <code>*.jb-vpn.uk</code> services.

== Configuration Errors ==

=== Syntax Errors ===

'''Symptoms''': <code>nginx -t</code> fails with syntax errors

'''Solutions''':
* Check for missing semicolons

* Verify bracket matching

* Check for typos in directive names

=== Duplicate Server Names ===

'''Symptoms''': Warning about duplicate server_name

'''Solutions''':
* Check all configuration files in <code>/etc/nginx/sites-enabled/</code>

* Remove duplicate server_name entries

* Ensure only one config per subdomain

== Service Issues ==

=== Nginx Won't Start ===

==== '''Check status''': ====
   <pre class="lang-bash">
   systemctl status nginx
</pre>

== '''Check logs''': ==
   <pre class="lang-bash">
   journalctl -u nginx -n 50
</pre>

== '''Test configuration''': ==
   <pre class="lang-bash">
   nginx -t
</pre>

=== Nginx Reload Fails ===

==== '''Test configuration first''': ====
   <pre class="lang-bash">
   nginx -t
</pre>

== '''Check for syntax errors''' in configuration files ==

== '''Verify file permissions''': ==
   <pre class="lang-bash">
   ls -la /etc/nginx/sites-enabled/
</pre>

== Log Analysis ==

=== Error Logs ===

<pre class="lang-bash">
==== View recent errors ====
tail -f /var/log/nginx/error.log

== Search for specific errors ==
grep "error" /var/log/nginx/error.log
</pre>

=== Access Logs ===

<pre class="lang-bash">
==== View recent access ====
tail -f /var/log/nginx/access.log

== Analyze traffic ==
awk '{print $1}' /var/log/nginx/access.log | sort | uniq -c | sort -rn
</pre>

== Common Configuration Issues ==

=== SSL Certificate Problems ===

* Verify certificate exists: <code>certbot certificates</code>

* Check certificate expiration: <code>openssl x509 -in /etc/letsencrypt/live/domain/cert.pem -noout -dates</code>

* Renew if needed: <code>certbot renew</code>

=== Proxy Issues ===

* Check proxy_pass URL is correct

* Verify target service is accessible

* Check proxy headers are set correctly

== Related Documentation ==

* [Adding Services](index.md) - Service configuration

* [Service Management](service-management.md) - Service management

[[Category:Documentation]]
[[Category:Documentation/Troubleshooting]]