Integrate an external Identity Provider

In order to provide a higher security level, you may need to protect your endpoints using an external Identity Provider (IdP) such as Okta, Keycloak, etc.

This page will guide you through the integration of an external IdP in your Mia-Platform project.

Definition

The involved microservice of the flow are:

1. API Gateway: Mia-Platform plugin available in Nginx or Envoy
2. Authorization Service: Mia-Platform plugin
3. Authentication Manager: a custom microservice that you need to implement. It must integrate with your external IdP to resolve the user token.
4. The microservice connected to the endpoint

The picture above illustrates the steps of the auth flow:

1. The client, be it a web application or a backend software, needs to implement the authentication flow required by the IdP to obtain a valid token. With this token, the client will be able to call the endpoints of your project.
2. The client calls the endpoint of your project, including the valid token in the request. Usually this token is placed in the Authorization header but it can be placed in other headers or cookies.
3. The API Gateway calls the Authorization Service which is in charge to verify if the user who made the request is authorized to access to the requested endpoint.
4. To do so, the Authorization Service requests to the Authentication Manager to resolve the token
5. The Authentication Service resolves the token by contacting the external IdP and returns the user payload to the Authorization Service that can now check if the user belongs to the authorized groups
6. If the verification performed by the Authentication Service is successful, then the API Gateway forwards the original HTTP request the right microservice of the project. Note that the target microservice will receive the following additional headers that could be useful for their business logic:

Header	Description
Miausergroups	comma separated list of the groups the user belongs to
Miauserid	the ID of the user
Miauserproperties	stringified JSON object containing the user payload returned by the Authentication Service

Tutorial steps

note

We suppose that you have already created an API Gateway in your project and you already have some endpoints you want to secure.

In order to implement the flow depicted above, you can perform the following steps on Mia-Platform Console:

1. Create the Authentication Manager custom microservice

   • Click on Microservices
   • Click on Create a Microservice and select From Markeplace
   • Choose your preferred template to start coding your custom Authentication Service
   • Implement the /userinfo endpoint. It must resolve the token on the external IdP and then return as response body a JSON object with at least the userID and the groups. An example of response is:

     {
       "userID": "123",
       "groups": ["admin", "users"]
     }

2. Create the Authorization Service plugin from Marketplace

   • Click on Microservices

   • Click on Create a Microservice and select From Markeplace

   • Search authorization in the search bar

   • Select Authorization Service

   • Click on Create

   • Update the values of the following environment variables:

     Variable	Value
     USERINFO_URL	http://authentication-service/userinfo
     CUSTOM_USER_ID_KEY	userID
     HEADERS_TO_PROXY	<header of the client's request containing the token> (e.g. Authorization)
     AUTHORIZATION_HEADERS_TO_PROXY	<header of the client's request containing the token> (e.g. Authorization)
     USER_PROPERTIES_TO_PROXY	userID,groups

3. Secure the endpoint

   • Select the endpoint you want to secure in the Endpoints section of your project
   • Use the User Group Permission textbox to choose the user groups authorized to call the endpoint. For example, if you want to allow access only to admin or users you should insert:

     groups.admin || groups.users

     info

     Scenario 1 and scenario 2 can be combined, and you could have complex group expressions like the following:

     (clientType === 'A' || clientType === 'B') && (groups.admin || groups.users)