How to Fix 403 Forbidden Error in Nginx Inside Docker

🚀 Cómo solucionar el error paso a paso

Paso 1: Corregir los permisos del sistema de archivos local

The user inside the Nginx container (usually nginx or www-data with UID 101 or 82) requires read permissions on files and execution permissions on directories in your shared folder. On your Linux server, adjust the privileges by running:

# Cambiar la propiedad al usuario y grupo del servidor web si es necesario,
# o asegurar permisos de lectura globales (lectura para archivos, lectura+ejecución para carpetas):
sudo find /ruta/local/a/tus/archivos/web -type d -exec chmod 755 {} \;
sudo find /ruta/local/a/tus/archivos/web -type f -exec chmod 644 {} \;

Paso 2: Verificar el archivo de inicio (Index)

Make sure that the server block in your Nginx configuration (nginx.conf or the file in conf.d) looks for an existing file. Check that the main file of your directory is named exactly as follows and in lowercase:

• index.html
• index.php

A mismatch in capitalization (such as Index.html or INDEX.HTML) will cause the 403 failure immediately on Linux systems because the filesystem is case-sensitive.

🛡️ Consejo de Prevención

Recommended safety practices:

• When working on Red Hat-based distributions (such as CentOS, Rocky Linux, or Fedora), prevent SELinux security policies on the host system from blocking access to the container's file descriptors. Whenever you configure a local volume mount, add the shared security flag :Z to the end of the volume path in your command or Docker Compose file:
  YAML Copy

  volumes:
    - /ruta/local:/usr/share/nginx/html:Z