Fix Gunicorn Socket Permission Denied (Nginx + Django)

If you're seeing errors like:

• connect() to unix:/.../gunicorn.sock failed (13: Permission denied)
• Nginx returns 502 Bad Gateway
• Gunicorn appears to be running, but requests fail

👉 Then you have a socket permission issue

This guide shows you exactly how to diagnose and fix it step-by-step.

⚡ Quick Fix (Try This First)

Run:

sudo chown -R www-data:www-data /var/www/myproject
sudo chmod 755 /var/www/myproject
sudo systemctl restart gunicorn
sudo systemctl restart nginx

Then reload your site.

👉 If still broken, continue below.

🧠 What This Error Means

In this setup:

• Gunicorn creates a socket file
• Nginx connects to it

Permission denied means:

Nginx does not have permission to access the socket file

🧪 Step-by-Step Diagnosis

1. Locate the socket file

ls -l /var/www/myproject/

Look for:

srwxrwx--- 1 www-data www-data gunicorn.sock

👉 If missing:

• Gunicorn is not creating the socket

2. Check ownership

ls -l /var/www/myproject/gunicorn.sock

Expected:

www-data www-data

👉 If different:

• Nginx cannot access it

3. Check Gunicorn service config

sudo nano /etc/systemd/system/gunicorn.service

Ensure:

[Service]
User=www-data
Group=www-data

👉 This ensures Gunicorn creates the socket with the correct permissions

4. Check directory permissions

ls -ld /var/www/myproject

Expected:

drwxr-xr-x www-data www-data

👉 If too restrictive:

Nginx cannot traverse directory to access socket

5. Restart Gunicorn

sudo systemctl restart gunicorn

Then check socket again.

6. Check Nginx config

sudo nano /etc/nginx/sites-available/myproject

or your favorite editor.

Ensure:

proxy_pass http://unix:/var/www/myproject/gunicorn.sock;

👉 Path must match exactly

🔥 Common Causes (and Fixes)

🔴 Wrong file ownership

Fix:

sudo chown -R www-data:www-data /var/www/myproject

sudo chown -R www-data:www-data /var/www/myproject

🔴 Gunicorn running as wrong user

Fix:

User=www-data
Group=www-data

Then:

sudo systemctl daemon-reexec
sudo systemctl restart gunicorn

🔴 Directory permissions too strict

Fix:

sudo chmod 755 /var/www/myproject

🔴 Socket permissions incorrect

Fix:

sudo chmod 660 /var/www/myproject/gunicorn.sock

🔴 Nginx running as different user

Check:

ps aux | grep nginx

Usually:

www-data

👉 Must match Gunicorn group

🧠 Debugging Tips

Check Nginx logs

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

Look for:

• permission denied
• socket errors

Check Gunicorn logs

journalctl -u gunicorn

Check socket permissions directly

stat /var/www/myproject/gunicorn.sock

✅ Quick Fix Checklist

• Socket file exists
• Owned by www-data
• Gunicorn runs as www-data
• Directory permissions allow access
• Nginx uses correct socket path
• Services restarted

🔗 Related Guides

• Fix Django 502 Bad Gateway
• Nginx not connecting to Gunicorn
• Deploy Django with Nginx + Gunicorn

❓ FAQ

Why does this error happen?

Because:

• Gunicorn creates the socket
• Nginx cannot access it

Should I use sockets or ports?

• Sockets → faster, more efficient
• Ports → easier debugging

Why does restarting fix it sometimes?

Because:

• Socket gets recreated with correct permissions

🎯 Final takeaway

“Permission denied” means:

Nginx cannot access Gunicorn’s socket

Fix it by ensuring:

• Correct ownership
• Correct permissions
• Matching configuration

If you deploy often…

A repeatable, tested setup will prevent this issue entirely.