OAuth

This feature is available in Gloo Enterprise only. If you are using the open source version of Gloo, this tutorial will not work.

Gloo supports authentication via OpenID Connect (OIDC). OIDC is an identity layer on top of the OAuth 2.0 protocol. In OAuth 2.0 flows, authentication is performed by an external Identity Provider (IdP) which, in case of success, returns an Access Token representing the user identity. The protocol does not define the contents and structure of the Access Token, which greatly reduces the portability of OAuth 2.0 implementations.

The goal of OIDC is to address this ambiguity by additionally requiring Identity Providers to return a well-defined ID Token. OIDC ID tokens follow the JSON Web Token standard and contain specific fields that your applications can expect and handle. This standardization allows you to switch between Identity Providers - or support multiple ones at the same time - with minimal, if any, changes to your downstream services; it also allows you to consistently apply additional security measures like Role-based Access Control (RBAC) based on the identity of your users, i.e. the contents of their ID token (check out this guide for an example of how to use Gloo to apply RBAC policies to JWTs).

In this guide, we will focus on the format of the Gloo API for OIDC authentication.

This feature requires Gloo’s external auth server to communicate with an external OIDC provider/authorization server. Because of this interaction, the OIDC flow may take longer than the default timeout of 200ms. You can increase this timeout by setting the requestTimeout value on external auth settings . The external auth settings can be configured on the global Gloo Settings object .

Configuration format

The auth configuration format shown on this page was introduced with Gloo Enterprise, release 0.20.1. If you are using an earlier version, please refer to this page to see which configuration formats are supported by each version.

Following is an example of an AuthConfig with an OIDC configuration (for more information on AuthConfig CRDs, see the main page of the authentication docs):

apiVersion: enterprise.gloo.solo.io/v1
kind: AuthConfig
metadata:
  name: oidc
  namespace: gloo-system
spec:
  configs:
  - oauth:
      issuer_url: theissuer.com
      auth_endpoint_query_params:
        paramKey: paramValue
      app_url: myapp.com
      callback_path: /my/callback/path/
      client_id: myclientid
      client_secret_ref:
        name: my-oauth-secret
        namespace: gloo-system
      scopes:
      - email

The AuthConfig consists of a single config of type oauth. Let’s go through each of its attributes:

The callback path must have a matching route in the VirtualService associated with the OIDC settings. For example, you could simply have a / path-prefix route which would match any callback path. The important part of this callback “catch all” route is that it goes through the routing filters including external auth. Please see the examples for Google and Dex.

Examples

We have seen how a sample OIDC AuthConfig is structured. For complete examples of how to set up an OIDC flow with Gloo, check out the following guides: