求助：CodeIgniter站点部署至生产服务器后出现HTTP ERROR 500

Hey there, sorry to hear you're stuck with that frustrating 500 error after moving your site from staging to production. Since you’ve confirmed your .htaccess matches staging and mod_rewrite is enabled, let’s dive into the most likely issues to check:

• File & Directory Permissions: Production servers often enforce stricter permissions than staging. Double-check that:

  • Your PHP files are set to 644 (read/write for owner, read-only for others)
  • Directories are set to 755 (read/write/execute for owner, read/execute for others)
  • Any cache, upload, or temp directories have permissions that let the web server user (like www-data for Apache, nginx for Nginx) write to them (avoid 777—use 775 instead if needed)
  • File/directory owners match the web server user (use chown -R www-data:www-data /path/to/your/site if needed)

• PHP Configuration & Errors: Staging and production might have mismatched PHP setups:

  • Check if the PHP versions differ—some functions or syntax might be deprecated/removed in newer versions.
  • Enable error display temporarily (only for troubleshooting!) by adding this at the top of your index.php:

    ini_set('display_errors', 1);
    error_reporting(E_ALL);
    

  • Look for server error logs (common paths: /var/log/apache2/error.log for Apache, /var/log/nginx/error.log for Nginx, or PHP-FPM logs in /var/log/php-fpm/)—these will give you the specific error causing the 500 (e.g., missing extension, fatal function call).
  • Verify production PHP hasn’t disabled critical functions your code uses (check disable_functions in php.ini).

• Missing Dependencies or Extensions:

  • Compare PHP extensions between staging and production using php -m in both environments—look for missing extensions like mysqli, gd, curl, or mbstring.
  • If you use Composer, ensure you ran composer install --no-dev on production to install only production-ready dependencies (staging might have dev packages that aren’t deployed).

• Apache AllowOverride Configuration: Even with mod_rewrite enabled, your virtual host config might block .htaccess rules. Check if your production server’s virtual host has:

  AllowOverride All
  

  Or at minimum (for rewrite rules):

  AllowOverride FileInfo
  

  If it’s set to AllowOverride None, your .htaccess rules won’t apply and could trigger a 500.

• Environment-Specific Paths & Variables:

  • Look for hardcoded paths in your config (e.g., /var/www/staging/uploads) that don’t exist on production.
  • Verify environment variables (like database credentials, API keys) are correctly set on production—staging might have these in a .env file that wasn’t deployed.

• .htaccess Compatibility:

  • Even if the file matches staging, Apache version differences could break certain rules. Try renaming .htaccess to .htaccess.bak—if the 500 goes away, re-add rules one by one to find the problematic line.

• Cache Conflicts:

  • Production servers often use OPcache or APC for performance. Clear these caches by restarting your web server or PHP-FPM service, or manually deleting cache files if your app has a local cache directory.

The fastest way to narrow this down is always checking the server error logs—they’ll tell you exactly what’s failing, instead of guessing based on the generic 500 message.

内容的提问来源于stack exchange，提问作者user2670069