forward auth authelia

Authelia (forward auth or OIDC)

Authelia can sit in front of Muximux as either a forward-auth provider or an OIDC provider. This guide covers both. Forward auth is the original Authelia integration model and is the most common; OIDC is the more recent, more portable approach.

If you're not sure which to pick:

• Pick forward auth if Authelia is already protecting other apps in your stack via your reverse proxy (Traefik, Nginx, Caddy). It's the lighter setup.
• Pick OIDC if you want Muximux to authenticate against Authelia the same way it would authenticate against Keycloak or Entra ID, independent of your reverse proxy.

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Option A: Forward Auth (Traefik / Nginx / Caddy)

In this mode, your reverse proxy calls Authelia on every request. Authelia decides whether to allow the request and adds headers like Remote-User and Remote-Groups. Muximux trusts those headers.

Step 1: Configure Authelia

If you already have Authelia protecting other apps, you only need to add a rule for Muximux's host. In configuration.yml:

access_control:
  default_policy: deny
  rules:
    - domain: muximux.example.com
      policy: two_factor    # or one_factor; pick what suits your risk model

No special Authelia config is required for the headers themselves; Authelia emits Remote-User, Remote-Email, Remote-Name, and Remote-Groups by default.

Step 2: Configure the Reverse Proxy

The exact syntax depends on your proxy. The pattern is the same: forward Muximux's traffic to Authelia's /api/verify endpoint and copy the auth headers into the upstream request.

Traefik (file provider):

http:
  routers:
    muximux:
      rule: "Host(`muximux.example.com`)"
      service: muximux
      middlewares: [authelia]
      tls:
        certResolver: default

  services:
    muximux:
      loadBalancer:
        servers:
          - url: "http://muximux:8080"

  middlewares:
    authelia:
      forwardAuth:
        address: "http://authelia:9091/api/verify?rd=https://auth.example.com"
        trustForwardHeader: true
        authResponseHeaders:
          - Remote-User
          - Remote-Groups
          - Remote-Email
          - Remote-Name

Nginx: see Authelia's official Nginx integration page for the verbatim snippet, then point the protected location at Muximux.

Caddy: Authelia's Caddy integration page covers forward_auth directives.

Step 3: Configure Muximux

auth:
  method: forward_auth
  trusted_proxies:
    - 172.16.0.0/12       # whatever subnet your reverse proxy lives in
  headers:
    user: Remote-User
    email: Remote-Email
    groups: Remote-Groups
    name: Remote-Name
  logout_url: https://auth.example.com/logout

trusted_proxies is required: Muximux only honours auth headers that arrived from a trusted hop. Setting it to 0.0.0.0/0 defeats the protection; restrict it to your reverse proxy's actual address or subnet.

For admin promotion via groups, Authelia by default puts your group memberships into Remote-Groups as a comma-separated list. Muximux looks for any of admin, admins, or administrators (case-insensitive). If your admin group has a different name, set forward_auth_admin_groups on the auth block to name it instead:

auth:
  method: forward_auth
  forward_auth_admin_groups:
    - dashboard-admins

Step 4: Validate

1. Open https://muximux.example.com/. You should be redirected to Authelia's login page.
2. After you sign in (and complete 2FA if required), you should land on the Muximux dashboard.
3. Sign in as a user whose groups field in Authelia includes admin (or admins / administrators). The Settings gear should appear.

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Option B: Authelia as an OIDC Provider

Authelia can also act as an OIDC provider. In that mode you don't need any forward-auth wiring; Muximux talks to Authelia directly.

Step 1: Configure the OIDC Client in Authelia

Add a client to Authelia's configuration.yml:

identity_providers:
  oidc:
    hmac_secret: <a long random string>
    issuer_private_key: |
      -----BEGIN PRIVATE KEY-----
      ...
      -----END PRIVATE KEY-----
    clients:
      - id: muximux
        description: Muximux dashboard
        secret: '<bcrypt-hashed secret, see Authelia docs>'
        public: false
        authorization_policy: two_factor
        redirect_uris:
          - https://muximux.example.com/api/auth/oidc/callback
        scopes:
          - openid
          - profile
          - email
          - groups
        userinfo_signing_algorithm: none

Authelia stores client secrets as hashes; use authelia hash-password '<secret>' to generate one.

Step 2: Configure Muximux

auth:
  method: oidc
  oidc:
    enabled: true
    issuer_url: https://auth.example.com
    client_id: muximux
    client_secret: ${AUTHELIA_CLIENT_SECRET}     # the plaintext, not the hash
    redirect_url: https://muximux.example.com/api/auth/oidc/callback
    scopes:
      - openid
      - profile
      - email
      - groups
    username_claim: preferred_username
    email_claim: email
    groups_claim: groups
    display_name_claim: name
    admin_groups:
      - Muximux-Admins

issuer_url is the public base URL of your Authelia instance, no trailing path. Authelia exposes the OIDC discovery document at https://auth.example.com/.well-known/openid-configuration.

Step 3: Validate

Same as the OIDC case in any other provider: visit /login, click Login with SSO, sign in to Authelia, get redirected back to Muximux. Members of the group listed in admin_groups see the Settings gear.

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Troubleshooting

Symptom	Cause	Fix
Forward auth: Remote-User empty	The reverse proxy isn't forwarding the header, or the rule that protects Muximux didn't match.	Check the reverse-proxy logs for the response headers from /api/verify. They should include Remote-User.
Forward auth: requests bypass Authelia	A request reached Muximux from outside the trusted-proxy range.	Lock down access at the reverse proxy so direct connections to Muximux's port aren't possible from outside the proxy network.
Forward auth: admin gear missing for known admin user	Authelia is sending Remote-Groups: foo and Muximux's check is for admin/admins/administrators.	Either rename the admin group in Authelia, or set forward_auth_admin_groups in Muximux to your group's name.
OIDC: unauthorized_client from Authelia	Client secret in config.yaml doesn't match Authelia's stored hash.	Regenerate the hash with authelia hash-password and verify the plaintext you put in Muximux's environment matches.
OIDC: no groups claim in token	groups not in the client's scopes list in Authelia.	Add groups to both Authelia's client config (Step 1) and Muximux's scopes:.

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See Also

• Authentication overview for the rest of auth.oidc and auth.method: forward_auth.
• Other identity providers: Microsoft Entra ID, Keycloak, Authentik, Pocket ID, Zitadel, Google, Cloudflare Access.