How to Solve Permission Denied Errors in Django Logging Configurations

If you're configuring error logging for your Django application but encountering Permission Denied errors, particularly when moving from localhost to production, this guide will walk you through some key troubleshooting steps.

Scenario Overview

In this example, you have a Django application with a logging configuration set in settings.py. You’re attempting to save log output to a file called log.txt located at the project’s root (/home/xyz/public_html/projectname/log.txt). The simplified logging configuration might look like this:

LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'verbose': {
            'format': "[%(asctime)s] %(levelname)s [%(name)s:%(lineno)s] %(message)s",
            'datefmt': "%d/%b/%Y %H:%M:%S",
        },
    },
    'handlers': {
        'file': {
            'level': 'DEBUG',
            'class': 'logging.FileHandler',
            'filename': 'log.txt',
            'formatter': 'verbose',
        },
    },
    'loggers': {
        'django': {
            'handlers': ['file'],
            'level': 'DEBUG',
            'propagate': True,
        },
    },
}

This configuration works locally but raises the following error when deployed:

ValueError: Unable to configure handler 'file': [Errno 13] Permission denied: '/log.txt'

Understanding the Issue

When running on localhost, the Django app has direct access to the file system, often using your user permissions. However, when deployed online, it typically runs under a different user account (e.g., apache or www-data), which might not have permission to write to log.txt.

Furthermore, the mod_wsgi server may alter the working directory to the root (/) instead of the project directory, causing the logging handler to look for /log.txt rather than /home/xyz/public_html/projectname/log.txt.

Step-by-Step Solution

1. Use Absolute Paths in Logging Configuration

Update the filename attribute in your logging configuration to use an absolute path. Replace:

'filename': 'log.txt'

with:

'filename': '/home/xyz/public_html/projectname/log.txt'

2. Check File Permissions

Ensure the web server user (e.g., apache or www-data) has write permissions on log.txt. You can use:

sudo chown apache:apache /home/xyz/public_html/projectname/log.txt

To give read, write, and execute permissions, you can run:

chmod 660 /home/xyz/public_html/projectname/log.txt

Avoid using chmod 777 for security reasons, as it grants full permissions to all users.

3. Disable SELinux (If Necessary)

SELinux can restrict file access based on policies. Temporarily disabling SELinux for testing is possible, but a better long-term solution would be configuring SELinux to allow the web server user access to the log.txt file:

chcon -t httpd_sys_rw_content_t /home/xyz/public_html/projectname/log.txt

Check SELinux status with:

sestatus

If needed, disable SELinux temporarily:

setenforce 0

4. Verify Configuration and Restart Services

After making these adjustments, restart your web server to apply changes:

sudo systemctl restart httpd

Summary of Best Practices

• Always use absolute paths in production settings.
• Ensure appropriate user permissions without overexposing access.
• Configure SELinux to allow specific access rather than disabling it.