volt/configs/landlock/webserver.landlock

# Landlock Policy Template: Web Server (nginx, Apache, Caddy)
# This policy allows typical web server operations with minimal filesystem access
# Version: 1.0

# Policy metadata
policy:
  name: webserver
  version: "1.0"
  description: "Landlock policy for web servers (nginx, Apache, Caddy, etc.)"
  category: webserver
  author: "ArmoredLinux"

# Filesystem access rules
# Landlock uses an allowlist approach - only explicitly listed paths are accessible
filesystem:
  # Read-only access to application files
  read_only:
    # Web content directory
    - path: /var/www
      recursive: true
      description: "Web content root"

    # Configuration files (container-specific)
    - path: /etc/nginx
      recursive: true
      description: "Nginx configuration"

    - path: /etc/apache2
      recursive: true
      description: "Apache configuration"

    - path: /etc/caddy
      recursive: true
      description: "Caddy configuration"

    # SSL/TLS certificates
    - path: /etc/ssl/certs
      recursive: true
      description: "SSL certificates"

    - path: /etc/letsencrypt
      recursive: true
      description: "Let's Encrypt certificates"

    # System libraries and dependencies
    - path: /usr/lib
      recursive: true
      description: "System libraries"

    - path: /lib
      recursive: true
      description: "System libraries"

    # Timezone data
    - path: /usr/share/zoneinfo
      recursive: true
      description: "Timezone information"

    # DNS resolution
    - path: /etc/hosts
      recursive: false
      description: "Hosts file"

    - path: /etc/resolv.conf
      recursive: false
      description: "DNS resolver configuration"

  # Read-write access (ephemeral)
  read_write_ephemeral:
    # Temporary files
    - path: /tmp
      recursive: true
      storage_type: tmpfs
      description: "Temporary files (tmpfs)"

    # Runtime state
    - path: /var/run
      recursive: true
      storage_type: tmpfs
      description: "Runtime state files"

    - path: /run
      recursive: true
      storage_type: tmpfs
      description: "Runtime state files"

  # Read-write access (persistent)
  read_write_persistent:
    # Logs
    - path: /var/log/nginx
      recursive: true
      storage_type: persistent
      description: "Nginx logs"

    - path: /var/log/apache2
      recursive: true
      storage_type: persistent
      description: "Apache logs"

    - path: /var/log/caddy
      recursive: true
      storage_type: persistent
      description: "Caddy logs"

    # Cache directories
    - path: /var/cache/nginx
      recursive: true
      storage_type: persistent
      description: "Nginx cache"

    - path: /var/cache/apache2
      recursive: true
      storage_type: persistent
      description: "Apache cache"

    # Upload directories (if needed)
    - path: /var/www/uploads
      recursive: true
      storage_type: persistent
      description: "Upload directory"

  # Execute access
  execute:
    # Web server binaries
    - path: /usr/sbin/nginx
      description: "Nginx binary"

    - path: /usr/sbin/apache2
      description: "Apache binary"

    - path: /usr/bin/caddy
      description: "Caddy binary"

    # Shell and utilities (only if needed for CGI/PHP-FPM)
    # Comment out if not needed for better security
    # - path: /bin/sh
    #   description: "Shell for CGI scripts"

# Network access
# These are enforced by systemd-nspawn and firewall rules, not Landlock
network:
  # Allow binding to these ports
  bind_ports:
    - port: 80
      protocol: tcp
      description: "HTTP"

    - port: 443
      protocol: tcp
      description: "HTTPS"

    - port: 8080
      protocol: tcp
      description: "Alternative HTTP"

  # Allow outbound connections to these destinations
  egress:
    # DNS lookups
    - port: 53
      protocol: udp
      description: "DNS queries"

    # NTP (for time synchronization)
    - port: 123
      protocol: udp
      description: "NTP time sync"

    # Backend API servers (configure as needed)
    # - host: backend.example.com
    #   port: 8000
    #   protocol: tcp
    #   description: "Backend API"

# Capabilities (Linux capabilities to grant)
# Web servers typically need very few capabilities
capabilities:
  # NET_BIND_SERVICE allows binding to ports < 1024
  - CAP_NET_BIND_SERVICE

  # CHOWN allows changing file ownership (for uploaded files)
  # - CAP_CHOWN  # Uncomment if needed

  # SETUID/SETGID for dropping privileges
  # - CAP_SETUID
  # - CAP_SETGID

# System calls allowed (this is a Landlock extension)
# For full control, use seccomp profiles instead
syscalls:
  # File operations
  allow:
    - open
    - openat
    - read
    - write
    - close
    - stat
    - fstat
    - lseek
    - mmap
    - munmap
    - sendfile

    # Network operations
    - socket
    - bind
    - listen
    - accept
    - accept4
    - connect
    - sendto
    - recvfrom
    - setsockopt
    - getsockopt

    # Process operations
    - fork
    - clone
    - execve
    - wait4
    - exit
    - exit_group

    # Time
    - gettimeofday
    - clock_gettime

# Enforcement mode
enforcement:
  # Mode: strict, permissive, or learning
  # - strict: Violations are blocked and logged
  # - permissive: Violations are logged but allowed
  # - learning: Violations are logged for policy development
  mode: strict

  # Log violations to syslog
  log_violations: true

  # Fail closed if Landlock is not available
  require_landlock: true

# Security notes
notes: |
  This policy is designed for typical web servers serving static content
  or proxying to backend services. Adjust paths based on your specific
  web server and application requirements.

  For PHP applications, you may need to add:
  - /usr/bin/php or /usr/bin/php-fpm
  - /var/lib/php/sessions (for PHP sessions)

  For applications with uploads, ensure /var/www/uploads is writable
  and consider additional restrictions on executable permissions.

  Always test policies in permissive mode first before enforcing in production.