Centos 7 Nginx Error Log Not Write

What is Nginx?

Nginx is an open source web server and web application framework created by Igor Sysoev for the common website hosting process. It is one of the most popular web servers currently in use and is capable of providing powerful web services such as HTTP, DNS, SMTP, and even streaming media. Working with Nginx requires a general understanding of how a web server works, but once learned, its features and simplicity makes it one of the most popular and reliable web servers available.

Nginx is frequently used as a reverse proxy server for HTTP, HTTPS, SMTP, POP3, and IMAP because it offers the following features: zero downtime restart, content caching, efficient memory usage, and the ability to handle heavy loads with minimal hardware. This makes it a great solution for busy web servers and applications.

Why is Nginx Not Writing Errors to Logs in CentOS 7?

There could be a number of reasons why Nginx is not writing errors to logs in CentOS 7. The most common cause is that the web server’s configuration file (nginx.conf) is either incorrect, or missing information. Another possible cause of this issue is that the log directory (where the error log is saved) is not writable by the nginx user.

Troubleshooting and Fixing the Nginx Error Log Issue in CentOS 7

The first step in troubleshooting and fixing the Nginx error log issue on CentOS 7 is to check and make sure that the nginx.conf file is correctly configured. It should include the following lines for error log:

error_log /var/log/nginx/error.log;
error_log /var/log/nginx/error.log notice;
error_log /var/log/nginx/error.log info;

It is important to put these lines in the correct order, as they can interfere with each other if listed in a wrong order. If you have any other lines in the configuration file that begin with the keyword error_log, then they should be removed.

Once the nginx.conf file is configured, we need to make sure that the log directory (where the error log is saved) is writable by the nginx user. The best way to do this is to change the ownership of the directory. This can be done by running the following command as root:

chown -R nginx:nginx /var/log/nginx

This command will change the ownership of the log directory and all of its contents to nginx, which should allow the nginx web server user to write to the log files.

Testing to See if Nginx is Writing Errors to Logs Now

To check if Nginx is now writing errors to the log, we can use the command line utility “tail” to view the end of the error log.

On a typical CentOS 7 server, the command to use is:

tail -f /var/log/nginx/error.log

This will print the last few lines of the error log to the terminal. If Nginx is correctly writing errors to the log, then you should see entries for errors and warnings.

Debugging Common Nginx Configuration Issues

There are a few common Nginx configuration issues that can cause problems with the error log.

One example is the use of the “ErrorDocument” directive in the nginx.conf. This directive is used to override the default response for HTTP errors, and can interfere with writing to the error log if not configured correctly. It should only be used when absolutely necessary and should be removed if it is not being used.

Another common issue is incorrect usage of server_name directives. Each server block in the nginx.conf must have its own server_name directive and the correct domain name. If these are configured incorrectly, Nginx may not be able to write to the log files.

Common Error Messages in the Nginx Error Log

When troubleshooting Nginx errors, the first place to check is the error log. There are a few common error messages that you may see in the log.

The most common error message is “No captive portal detected”. This message indicates that Nginx was unable to detect the captive portal page for a given domain. This could be caused by a misconfigured SSL certificate, a misconfigured server_name directive, or even a DNS issue.

Another common message is “403 Forbidden”. This message indicates that Nginx is not allowing access to the requested page. This could be due to a misconfigured directory or file permissions, or an incorrect setting in the nginx.conf.

A third error message is “404 Not Found”. This message indicates that the requested page could not be found. This could be due to a misconfigured URL redirect, a missing index file, or a broken link.

FAQs

Q: How Do I Configure Nginx to Log Errors?

A: To configure Nginx to log errors, you need to add the following lines to your nginx.conf file: error_log /var/log/nginx/error.log; error_log /var/log/nginx/error.log notice; error_log /var/log/nginx/error.log info;. You also need to make sure that the log directory (where the error log is saved) is writable by the nginx user. The best way to do this is to change the ownership of the directory using the command “chown -R nginx:nginx /var/log/nginx”.

Q: What Are Some Common Error Messages in the Nginx Error Log?

A: Some common error messages in the Nginx error log are “No captive portal detected”, “403 Forbidden”, and “404 Not Found”. These messages indicate different issues and should be investigated further to determine the root cause of the issue.

Conclusion

In summary, understanding how to troubleshoot and fix the Nginx error log issue on CentOS 7 is important for maintaining a stable and reliable web server. By checking the log directory and making sure that the nginx.conf file is correctly configured, it is usually straightforward to determine the cause of the issue and take the necessary steps to fix it.

Thank you for reading this article. Please read our other articles to get more insights on CentOS 7 and Nginx.