Self-Host Authelia: Authentication Middleware 2026

TL;DR

Authelia (Apache 2.0, ~21K GitHub stars, Go) is authentication middleware that sits in front of your reverse proxy and adds login, 2FA, and access control to any self-hosted app. Unlike Authentik (which is a full identity provider), Authelia is focused purely on authentication — it's lighter, faster, and simpler to configure for the common use case of protecting your homelab behind a single sign-on portal. ~50MB RAM vs Authentik's ~500MB.

Key Takeaways

• Authelia: Apache 2.0, ~21K stars, Go — auth middleware for Caddy/Nginx/Traefik
• Minimal resources: ~50MB RAM — runs on the smallest VPS or Raspberry Pi
• 2FA: TOTP (Google Authenticator), WebAuthn (hardware keys), push notifications
• Access policies: Per-domain access rules — require different auth levels per app
• LDAP support: Connect to LDAP/Active Directory for user management
• vs Authentik: Authelia is simpler, lighter, and not an OAuth2 provider

---

Authelia vs Authentik

Feature	Authelia	Authentik
RAM usage	~50MB	~500MB
Setup complexity	Low	Medium
Config style	YAML files	Web UI
OAuth2/OIDC Provider	No	Yes
SAML Provider	No	Yes
Proxy authentication	Yes	Yes (Outposts)
User management	YAML/LDAP	Web UI
Flow customization	No	Yes
Best for	Simple 2FA gateway	Full IdP with app management

---

Part 1: Docker Setup

# docker-compose.yml
services:
  authelia:
    image: authelia/authelia:latest
    container_name: authelia
    restart: unless-stopped
    volumes:
      - ./authelia/config:/config
      - authelia_data:/data
    ports:
      - "9091:9091"
    environment:
      TZ: America/Los_Angeles
    depends_on:
      - redis

  redis:
    image: redis:7-alpine
    container_name: authelia-redis
    restart: unless-stopped
    volumes:
      - redis_data:/data
    command: redis-server --save 60 1

volumes:
  authelia_data:
  redis_data:

---

Part 2: Configuration Files

Create the configuration directory and files:

mkdir -p ./authelia/config

Main configuration

# ./authelia/config/configuration.yml

server:
  host: 0.0.0.0
  port: 9091

log:
  level: info

# JWT secret for session tokens:
jwt_secret: "${JWT_SECRET}"   # openssl rand -hex 32

# Default redirection URL after login:
default_redirection_url: "https://yourdomain.com"

# Totp configuration:
totp:
  issuer: yourdomain.com

# Duo 2FA (optional):
# duo_api:
#   hostname: api-123456789.duosecurity.com
#   integration_key: XXXX
#   secret_key: XXXX

# File-based user database (simple setup):
authentication_backend:
  file:
    path: /config/users.yml
    password:
      algorithm: argon2id
      iterations: 3
      memory: 65536
      parallelism: 4

# Access control policies:
access_control:
  default_policy: deny

  rules:
    # Allow public access to specific paths:
    - domain: "public.yourdomain.com"
      policy: bypass

    # Require 1FA for general apps:
    - domain: "*.yourdomain.com"
      policy: one_factor

    # Require 2FA for sensitive apps:
    - domain: "vault.yourdomain.com"
      policy: two_factor
    - domain: "portainer.yourdomain.com"
      policy: two_factor
    - domain: "proxmox.yourdomain.com"
      policy: two_factor

# Session configuration:
session:
  name: authelia_session
  secret: "${SESSION_SECRET}"   # openssl rand -hex 32
  expiration: 1h
  inactivity: 5m
  remember_me_duration: 1M

  redis:
    host: redis
    port: 6379

# Storage (SQLite for simplicity):
storage:
  encryption_key: "${STORAGE_ENCRYPTION_KEY}"   # openssl rand -hex 32
  local:
    path: /data/db.sqlite3

# Notification (email):
notifier:
  smtp:
    username: authelia@yourdomain.com
    password: "${MAIL_PASSWORD}"
    host: mail.yourdomain.com
    port: 587
    sender: "Authelia <authelia@yourdomain.com>"
    tls:
      skip_verify: false

User database

# ./authelia/config/users.yml
# Generate password hash: docker run authelia/authelia:latest authelia crypto hash generate argon2 --password "yourpassword"

users:
  yourname:
    disabled: false
    displayname: "Your Name"
    password: "$argon2id$v=19$m=65536,t=3,p=4$..."   # hash from above
    email: you@yourdomain.com
    groups:
      - admins
      - users
  alice:
    disabled: false
    displayname: "Alice"
    password: "$argon2id$v=19$m=65536,t=3,p=4$..."
    email: alice@yourdomain.com
    groups:
      - users

# Generate a password hash:
docker run --rm authelia/authelia:latest \
  authelia crypto hash generate argon2 --password "yourpassword"

---

Part 3: HTTPS with Caddy

Caddy forwards authentication checks to Authelia:

# Authelia itself:
auth.yourdomain.com {
    reverse_proxy authelia:9091
}

# Snippet for protected apps:
(authelia) {
    forward_auth authelia:9091 {
        uri /api/verify?rd=https://auth.yourdomain.com
        copy_headers Remote-User Remote-Groups Remote-Name Remote-Email
        trusted_proxies private_ranges
    }
}

# Portainer (requires 2FA per policy):
portainer.yourdomain.com {
    import authelia
    reverse_proxy portainer:9000
}

# Grafana:
grafana.yourdomain.com {
    import authelia
    reverse_proxy grafana:3000
}

# Nextcloud (bypass Authelia — Nextcloud has its own auth):
nextcloud.yourdomain.com {
    reverse_proxy nextcloud:80
}

---

Part 4: Nginx Integration

For Nginx users:

# /etc/nginx/snippets/authelia-location.conf
location /authelia {
    internal;
    proxy_pass http://127.0.0.1:9091/api/verify;
    proxy_pass_request_body off;
    proxy_set_header Content-Length "";
    proxy_set_header X-Original-URL $scheme://$http_host$request_uri;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_set_header X-Forwarded-Host $http_host;
    proxy_set_header X-Forwarded-Uri $request_uri;
    proxy_set_header X-Forwarded-Method $request_method;
    proxy_connect_timeout 5s;
    proxy_read_timeout 10s;
}

# Protected virtual host:
server {
    listen 443 ssl;
    server_name portainer.yourdomain.com;

    include /etc/nginx/snippets/ssl.conf;

    location / {
        auth_request /authelia;
        auth_request_set $target_url $scheme://$http_host$request_uri;
        auth_request_set $user $upstream_http_remote_user;
        auth_request_set $groups $upstream_http_remote_groups;
        error_page 401 =302 https://auth.yourdomain.com/?rd=$target_url;

        proxy_set_header Remote-User $user;
        proxy_set_header Remote-Groups $groups;
        proxy_pass http://portainer:9000;
    }
}

---

Part 5: 2FA Setup

TOTP (Authenticator apps)

1. Log in to any protected app → redirected to Authelia
2. Click Register device → Time-based One-Time Password
3. Scan QR code with Google Authenticator, Aegis, or Bitwarden
4. Enter code to confirm

WebAuthn (Hardware keys / Face ID / Touch ID)

1. Log in → Register device → WebAuthn device
2. Plug in YubiKey or use Face ID/Touch ID on supported devices
3. Name the device → confirm

Disable 2FA for specific apps

# In configuration.yml:
access_control:
  rules:
    # Internal apps — no 2FA needed:
    - domain: "homeassistant.yourdomain.com"
      networks:
        - 192.168.1.0/24    # Local network only
      policy: bypass

    # Or: one_factor (password only, no TOTP):
    - domain: "jellyfin.yourdomain.com"
      policy: one_factor

---

Part 6: LDAP Backend

For larger setups, replace the file backend with LDAP:

# configuration.yml:
authentication_backend:
  ldap:
    implementation: custom    # or: activedirectory, lldap, glauth
    url: "ldap://lldap:3890"
    base_dn: "dc=yourdomain,dc=com"
    username_attribute: uid
    additional_users_dn: "ou=people"
    users_filter: (&({username_attribute}={input})(objectClass=person))
    additional_groups_dn: "ou=groups"
    groups_filter: "(member={dn})"
    group_name_attribute: cn
    mail_attribute: mail
    display_name_attribute: displayName
    user: "cn=admin,dc=yourdomain,dc=com"
    password: "${LDAP_PASSWORD}"

Pair with lldap — a lightweight LDAP server designed specifically for self-hosted setups.

---

Part 7: Access Control Patterns

access_control:
  default_policy: deny

  rules:
    # 1. Bypass healthcheck endpoints:
    - domain: "*.yourdomain.com"
      resources:
        - "^/health$"
        - "^/metrics$"
      policy: bypass

    # 2. Local network gets 1FA only:
    - domain: "*.yourdomain.com"
      networks:
        - 192.168.1.0/24
        - 10.0.0.0/8
      policy: one_factor

    # 3. Admin group gets access to admin tools:
    - domain: "portainer.yourdomain.com"
      subject:
        - "group:admins"
      policy: two_factor

    # 4. Users group gets access to media:
    - domain: "jellyfin.yourdomain.com"
      subject:
        - "group:users"
        - "group:admins"
      policy: one_factor

    # 5. Block everyone else from everything:
    - domain: "*.yourdomain.com"
      policy: deny

---

Maintenance

# Update:
docker compose pull
docker compose up -d

# Validate configuration:
docker exec authelia authelia validate-config --config /config/configuration.yml

# Backup:
# SQLite database:
docker cp authelia:/data/db.sqlite3 authelia-backup-$(date +%Y%m%d).db

# Config files:
cp -r ./authelia/config ./authelia-config-backup-$(date +%Y%m%d)

# Logs:
docker compose logs -f authelia

# Test authentication flow:
curl -v "https://auth.yourdomain.com/api/health"

Why Self-Host Authelia?

The case for self-hosting Authelia comes down to three practical factors: data ownership, cost at scale, and operational control.

Data ownership is the fundamental argument. When you use a SaaS version of any tool, your data lives on someone else's infrastructure subject to their terms of service, their security practices, and their business continuity. If the vendor raises prices, gets acquired, changes API limits, or shuts down, you're left scrambling. Self-hosting Authelia means your data and configuration stay on infrastructure you control — whether that's a VPS, a bare metal server, or a home lab.

Cost at scale matters once you move beyond individual use. Most SaaS equivalents charge per user or per data volume. A self-hosted instance on a $10-20/month VPS typically costs less than per-user SaaS pricing for teams of five or more — and the cost doesn't scale linearly with usage. One well-configured server handles dozens of users for a flat monthly fee.

Operational control is the third factor. The Docker Compose configuration above exposes every setting that commercial equivalents often hide behind enterprise plans: custom networking, environment variables, storage backends, and authentication integrations. You decide when to update, how to configure backups, and what access controls to apply.

The honest tradeoff: you're responsible for updates, backups, and availability. For teams running any production workloads, this is familiar territory. For individuals, the learning curve is real but the tooling (Docker, Caddy, automated backups) is well-documented and widely supported.

Server Requirements and Sizing

Before deploying Authelia, assess your server capacity against expected workload.

Minimum viable setup: A 1 vCPU, 1GB RAM VPS with 20GB SSD is sufficient for personal use or small teams. Most consumer VPS providers — Hetzner, DigitalOcean, Linode, Vultr — offer machines in this range for $5-10/month. Hetzner offers excellent price-to-performance for European and US regions.

Recommended production setup: 2 vCPUs with 4GB RAM and 40GB SSD handles most medium deployments without resource contention. This gives Authelia headroom for background tasks, caching, and concurrent users while leaving capacity for other services on the same host.

Storage planning: The Docker volumes in this docker-compose.yml store all persistent Authelia data. Estimate your storage growth rate early — for data-intensive tools, budget for 3-5x your initial estimate. Hetzner Cloud and Vultr both support online volume resizing without stopping your instance.

Operating system: Any modern 64-bit Linux distribution works. Ubuntu 22.04 LTS and Debian 12 are the most commonly tested configurations. Ensure Docker Engine 24.0+ and Docker Compose v2 are installed — verify with docker --version and docker compose version. Avoid Docker Desktop on production Linux servers; it adds virtualization overhead and behaves differently from Docker Engine in ways that cause subtle networking issues.

Network: Only ports 80 and 443 need to be publicly accessible when running behind a reverse proxy. Internal service ports should be bound to localhost only. A minimal UFW firewall that blocks all inbound traffic except SSH, HTTP, and HTTPS is the single most effective security measure for a self-hosted server.

Backup and Disaster Recovery

Running Authelia without a tested backup strategy is an unacceptable availability risk. Docker volumes are not automatically backed up — if you delete a volume or the host fails, data is gone with no recovery path.

What to back up: The named Docker volumes containing Authelia's data (database files, user uploads, application state), your docker-compose.yml and any customized configuration files, and .env files containing secrets.

Backup approach: For simple setups, stop the container, archive the volume contents, then restart. For production environments where stopping causes disruption, use filesystem snapshots or database dump commands (PostgreSQL pg_dump, SQLite .backup, MySQL mysqldump) that produce consistent backups without downtime.

For a complete automated backup workflow that ships snapshots to S3-compatible object storage, see the Restic + Rclone backup guide. Restic handles deduplication and encryption; Rclone handles multi-destination uploads. The same setup works for any Docker volume.

Backup cadence: Daily backups to remote storage are a reasonable baseline for actively used tools. Use a 30-day retention window minimum — long enough to recover from mistakes discovered weeks later. For critical data, extend to 90 days and use a secondary destination.

Restore testing: A backup that has never been restored is a backup you cannot trust. Once a month, restore your Authelia backup to a separate Docker Compose stack on different ports and verify the data is intact. This catches silent backup failures, script errors, and volume permission issues before they matter in a real recovery.

Security Hardening

Self-hosting means you are responsible for Authelia's security posture. The Docker Compose setup provides a functional base; production deployments need additional hardening.

Always use a reverse proxy: Never expose Authelia's internal port directly to the internet. The docker-compose.yml binds to localhost; Caddy or Nginx provides HTTPS termination. Direct HTTP access transmits credentials in plaintext. A reverse proxy also centralizes TLS management, rate limiting, and access logging.

Strong credentials: Change default passwords immediately after first login. For secrets in docker-compose environment variables, generate random values with openssl rand -base64 32 rather than reusing existing passwords.

Firewall configuration:

ufw default deny incoming
ufw allow 22/tcp
ufw allow 80/tcp
ufw allow 443/tcp
ufw enable

Internal service ports (databases, admin panels, internal APIs) should only be reachable from localhost or the Docker network, never directly from the internet.

Network isolation: Docker Compose named networks keep Authelia's services isolated from other containers on the same host. Database containers should not share networks with containers that don't need direct database access.

VPN access for sensitive services: For internal-only tools, restricting access to a VPN adds a strong second layer. Headscale is an open source Tailscale control server that puts your self-hosted stack behind a WireGuard mesh, eliminating public internet exposure for internal tools.

Update discipline: Subscribe to Authelia's GitHub releases page to receive security advisory notifications. Schedule a monthly maintenance window to pull updated images. Running outdated container images is the most common cause of self-hosted service compromises.

Troubleshooting Common Issues

Container exits immediately or won't start

Check logs first — they almost always explain the failure:

docker compose logs -f authelia

Common causes: a missing required environment variable, a port already in use, or a volume permission error. Port conflicts appear as bind: address already in use. Find the conflicting process with ss -tlpn | grep PORT and either stop it or change Authelia's port mapping in docker-compose.yml.

Cannot reach the web interface

Work through this checklist:

1. Confirm the container is running: docker compose ps
2. Test locally on the server: curl -I http://localhost:PORT
3. If local access works but external doesn't, check your firewall: ufw status
4. If using a reverse proxy, verify it's running and the config is valid: caddy validate --config /etc/caddy/Caddyfile

Permission errors on volume mounts

Some containers run as a non-root user. If the Docker volume is owned by root, the container process cannot write to it. Find the volume's host path with docker volume inspect VOLUME_NAME, check the tool's documentation for its expected UID, and apply correct ownership:

chown -R 1000:1000 /var/lib/docker/volumes/your_volume/_data

High resource usage over time

Memory or CPU growing continuously usually indicates unconfigured log rotation, an unbound cache, or accumulated data needing pruning. Check current usage with docker stats authelia. Add resource limits in docker-compose.yml to prevent one container from starving others. For ongoing visibility into resource trends, deploy Prometheus + Grafana or Netdata.

Data disappears after container restart

Data stored in the container's writable layer — rather than a named volume — is lost when the container is removed or recreated. This happens when the volume mount path in docker-compose.yml doesn't match where the application writes data. Verify mount paths against the tool's documentation and correct the mapping. Named volumes persist across container removal; only docker compose down -v deletes them.

Keeping Authelia Updated

Authelia follows a regular release cadence. Staying current matters for security patches and compatibility. The update process with Docker Compose is straightforward:

docker compose pull          # Download updated images
docker compose up -d         # Restart with new images
docker image prune -f        # Remove old image layers (optional)

Read the changelog before major version updates. Some releases include database migrations or breaking configuration changes. For major version bumps, test in a staging environment first — run a copy of the service on different ports with the same volume data to validate the migration before touching production.

Version pinning: For stability, pin to a specific image tag in docker-compose.yml instead of latest. Update deliberately after reviewing the changelog. This trades automatic patch delivery for predictable behavior — the right call for business-critical services.

Post-update verification: After updating, confirm Authelia is functioning correctly. Most services expose a /health endpoint that returns HTTP 200 — curl it from the server or monitor it with your uptime tool.

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See also: Authentik — full identity provider with OAuth2/OIDC for apps that need programmatic authentication

See all open source security tools at OSSAlt.com/categories/security.