Traefik OpenID Connect Middleware

A traefik Plugin for securing the upstream service with OpenID Connect acting as a relying party.

[!NOTE] This document always represents the latest version, which may not have been released yet. Therefore, some features may not be available currently but will be available soon. You can use the GIT-Tags to check individual versions.

[!WARNING] This middleware is under development and only tested against ZITADEL yet. Although it should be compatible with any OIDC-compatible IDP.

Tested Providers

Provider	Status	Notes
ZITADEL	✅
Kanidm	✅	See GH-12
Microsoft EntraID	⚠️	See GH-15
HashiCorp Vault	❌	See GH-13

💡 Getting Started

Enable the plugin in your traefik configuration.

experimental:
  plugins:
    traefik-oidc-auth:
      moduleName: "github.com/sevensolutions/traefik-oidc-auth"
      version: "v0.3.2"

Add a middleware and reference it in a route.

http:
  services:
    whoami:
      loadBalancer:
        servers:
          - url: http://whoami:80

  middlewares:
    oidc-auth:
      plugin:
        traefik-oidc-auth:
          Provider:
            Url: "https://..."
            ClientId: "<YourClientId>"
            ClientSecret: "<YourClientSecret>"
            #UsePkce: true # Or use PKCE instead of a secret
          Scopes: ["openid", "profile", "email"]
          Authorization:
            AssertClaims:
              - Name: "preferred_username"
                AnyOf: ["alice@gmail.com", "bob@gmail.com"]
              - Name: "roles"
                AllOf: ["admin", "media"]
              - Name: "user.first_name"
                AnyOf: ["Alice"]
          Headers:
            MapClaims:
              - Claim: "preferred_username"
                Header: "X-Oidc-Username"
              - Claim: "sub"
                Header: "X-Oidc-Subject"

  routers:
    whoami:
      entryPoints: ["web"]
      rule: "HostRegexp(`.+`)"
      service: whoami
      middlewares: ["oidc-auth"]

🛠 Configuration Options

Plugin Config Block

Name	Required	Type	Default	Description
Secret	no	`string`	`MLFs4TT99kOOq8h3UAVRtYoCTDYXiRcZ`	A secret used for encryption. Must be a 32 character string.
Provider	yes	`Provider`	none	Identity Provider Configuration. See Provider block.
Scopes	no	`string[]`	`["openid", "profile", "email"]`	A list of scopes to request from the IDP.
CallbackUri	no	`string`	`/oidc/callback`	Defines the callback url used by the IDP. This needs to be registered in your IDP.
LoginUri	no	`string`	none	An optional url, which should trigger the login-flow. By default every url triggers a login-flow, if the user is not already logged in. If you set this to eg. `/login`, only this url will trigger a login-flow while all other requests return Unauthorized.
PostLoginRedirectUri	no	`string`	none	An optional static redirect url where the user should be redirected after login. By default the user will be redirected to the url which triggered the login-flow.
LogoutUri	no	`string`	`/logout`	The url which should trigger a logout-flow.
PostLogoutRedirectUri	no	`string`	`/`	The url where the user should be redirected after logout.
Authorization	no	`Authorization`	none	Authorization Configuration. See Authorization block.
Headers	no	`Headers`	none	Header Configuration. See Headers block.

Provider Block

Name	Required	Type	Default	Description
Url	no	`string`	none	The full URL of the Identity Provider. This is required, if UrlEnv is not used.
UrlEnv	no	`string`	none	The name of an environment variable, containing the full URL of the Identity Provider. This is required, if Url is not used.
ClientId	no	`string`	none	The client id of the application. This is required, if ClientIdEnv is not used.
ClientIdEnv	no	`string`	none	The name of an environment variable, containing the client id. This is required, if ClientId is not used.
ClientSecret	no	`string`	none	The client secret of the application. This is required, if ClientSecretEnv is not used and UsePkce is false.
ClientSecretEnv	no	`string`	none	The name of an environment variable, containing the client secret. This is required, if ClientSecret and UsePkce are not used.
UsePkce	no	`bool`	`false`	Enable PKCE. In this case, a client secret is not needed. The following algorithms are supported: RS, EC, ES.
ValidateIssuer	no	`bool`	`true`	Specifies whether the `iss` claim in the JWT-token should be validated.
ValidIssuer	no	`string`	discovery document	The issuer which must be present in the JWT-token. By default this will be read from the OIDC discovery document.
ValidIssuerEnv	no	`string`	none	The name of an environment variable, containing the valid issuer. This is required, if ValidIssuer is not used and ValidateIssuer is enabled.
ValidateAudience	no	`bool`	`true`	Specifies whether the `aud` claim in the JWT-token should be validated.
ValidAudience	no	`string`	ClientId	The audience which must be present in the JWT-token. Defaults to the configured client id.
ValidAudienceEnv	no	`string`	none	The name of an environment variable, containing the valid audience. This is required, if ValidAudience is not used and ValidateAudience is enabled.
TokenValidation	no	`string`	`AccessToken`	Specifies which token or method should be used to validate the authentication cookie. Can be either `AccessToken`, `IdToken` or `Introspection`. When using Microsoft EntraID, this will automatically default to `IdToken`. `Introspection` may not work when using PKCE.

Authorization Block

Name	Required	Type	Default	Description
AssertClaims	no	`ClaimAssertion[]`	none	ClaimAssertion Configuration. See ClaimAssertion block.

ClaimAssertion Block

If only the Name property is set and no additional assertions are defined it is only checked whether there exist any matches for the name of this claim without any verification on their values. Additionaly, the Name field can be any json path. The Name gets prefixed with $. to match from the root element. The usage of json paths allows for assertions on deeply nested json structures.

Name	Required	Type	Default	Description
Name	yes	`string`	none	The name of the claim in the access token.
AnyOf	no	`string[]`	none	An array of allowed strings. The user is authorized if any value matching the name of the claim contains (or is) a value of this array.
AllOf	no	`string[]`	none	An array of required strings. The user is only authorized if any value matching the name of the claim contains (or is) a value of this array and all values of this array are covered in the end.

It is possible to combine AnyOf and AllOf quantifiers for one assertion

Examples

All of the examples below work on this json structure: ```json { "store": { "bicycle": { "color": "red", "price": 19.95 }, "book": [ { "author": "Herman Melville", "category": "fiction", "isbn": "0-553-21311-3", "price": 8.99, "title": "Moby Dick" }, { "author": "J. R. R. Tolkien", "category": "fiction", "isbn": "0-395-19395-8", "price": 22.99, "title": "The Lord of the Rings" } ], } } ``` **Example**: Expect array to contain a set of values ```yaml Name: store.book[*].price AllOf: [ 22.99, 8.99 ] ``` This assertion would succeed as the `book` array contains all values specified by the `AllOf` quantifier ```yaml Name: store.book[*].price AllOf: [ 22.99, 8.99, 1 ] ``` This assertion would fail as the `book` array contains no entry for which the `price` is `1` **Example**: Expect object key to be any value of a set of values ```yaml Name: store.bicycle.color AnyOf: [ "red", "blue", "green" ] ``` This assertion would succeed as the `store` object contains a `bicycle` object whose `color` is `red`

Headers Block

Name	Required	Type	Default	Description
MapClaims	no	`ClaimHeader[]`	none	A list of claims which should be mapped as headers when the request will be sent to the upstream. See ClaimHeader block.

ClaimHeader Block

Name	Required	Type	Default	Description
Claim	yes	`string`	none	The name of the claim
Header	yes	`string`	none	The name of the header which should receive the claim value.

🧪 Local Development

Create the following .env file:

PROVIDER_URL=...
CLIENT_ID=...
CLIENT_SECRET=...

The run docker compose up to run traefik locally.

Now browse to http://localhost:9080. You should be redirected to your IDP. After you've logged in, you should be redirected back to http://localhost:9080 and see a WHOAMI page.

sevensolutions / traefik-oidc-auth

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