Getting Started
Check Nginx Configuration
Before troubleshooting specific errors, ensure that Nginx is properly configured:
Expected Output:
- If errors are present:
- Review the configuration file and included files in
/etc/nginx/conf.d/
. - Fix syntax errors or typos and re-test.
- Review the configuration file and included files in
Restart Nginx after resolving configuration issues:
502 Bad Gateway
Likely Causes
- The upstream server (backend) is unavailable or misconfigured.
- SSL handshake issues between Nginx and the upstream server.
Solution
-
Check Nginx Error Logs:
Look for messages such as
upstream timed out
orSSL handshake failure
. -
Fix SSL Certificate Issues:
- Replace
/etc/nginx/intigua.crt
and/etc/nginx/intigua.key
with valid SSL certificate and key files. - If the filenames change, update the SSL configuration in
/etc/nginx/conf.d/intigua.conf
.
- Replace
-
Verify Upstream Server Health:
- Test upstream server availability with:
- Ensure the upstream server is running and accessible.
-
Restart Nginx:
504 Gateway Timeout
Likely Causes
- The upstream server is slow or unresponsive.
- Nginx timeout values are too low.
- Firewall rules block communication between Nginx and the upstream server.
Solution
-
Verify Upstream Server Availability:
- Test the upstream server:
- If unreachable, resolve the issue on the upstream server or network.
-
Increase Timeout Values:
-
Add a configuration file
/etc/nginx/conf.d/timeout.conf
with the following content: -
Restart Nginx:
-
-
Check Firewall Rules:
- Ensure no firewall blocks traffic on relevant ports:
SELinux Blocking Connections
Symptom
- Nginx logs show errors like:
- SELinux logs (
/var/log/audit/audit.log
) show denial messages, such asname_connect
ortcp_socket
.
Solution
Check SELinux Logs
Run the following command to identify SELinux denials for Nginx:
If SELinux is blocking Nginx, you’ll see denial messages.
Enable Network Connections for Nginx
Allow Nginx to connect to external networks:
Switch SELinux Policy to Minimum
Change the SELinux policy type to focus on essential processes:
- Open the SELinux configuration file:
- Update the policy type:
- Save the file and reboot the system:
Restart Nginx
Apply the changes by restarting Nginx:
4. Unable to Access Proxy or Redirects
Likely Causes
- Firewall blocks traffic to or from Nginx.
- Incorrect Nginx configuration.
Solution
-
Test Internal Access:
- Open a browser and access:
- If this does not redirect to the login page, check the firewall and Nginx logs.
-
Check Firewall Rules:
- Verify HTTP (80), HTTPS (443), and WSUS ports (8530/8531) are open:
-
Validate Proxy Configuration:
- Confirm upstream settings in
/etc/nginx/conf.d/<file>.conf
are correct.
- Confirm upstream settings in
5. Other Issues
Symptom
- Proxy script fails to apply changes.
Solution
-
Re-run the Proxy Script:
-
Check Logs:
- Review the script output and Nginx logs for errors.
- Address any specific issues reported.
Comments
0 comments
Article is closed for comments.