Centralized Role Management for Microservices with Keycloak

Question

Pulumi · Accepted Answer

Centralized Role Management is a crucial aspect of securing microservices, allowing you to manage access control across your services from a single point. Keycloak is an open-source Identity and Access Management tool which makes it easy to secure your applications by providing mechanisms for authentication, authorization, and administration.

In the context of microservices, Keycloak can be used to manage roles and permissions for individual services, and users, making it easier to control who has access to what across your entire application infrastructure.

Below is a Pulumi program written in Python that demonstrates how to set up a Keycloak instance, define a realm, a client, roles, users, and groups. The program assumes you have a Pulumi project set up and the necessary Keycloak provider configured.

```python
import pulumi
import pulumi_keycloak as keycloak

# Create a new Keycloak Realm. A realm in Keycloak is a space where managed users, credentials, roles, and groups will reside.
my_realm = keycloak.Realm("my-realm",
    realm="my-realm",
    enabled=True,
    # This is where other configurations like SMTP servers for emails can be defined.
)

# Create a client. A client in Keycloak represents an application that will be secured by Keycloak.
my_client = keycloak.openid.Client("my-client",
    realm_id=my_realm.id,
    client_id="my-microservice",
    name="My Microservice",
    enabled=True,
    secret="verysecret",
    access_type="CONFIDENTIAL", # This client requires a secret to initiate the login process.
    valid_redirect_uris=["http://localhost:8080/*"], # The URI where the client will be redirected after authentication.
)

# Create roles. Roles represent the permissions that will be granted to users or groups.
user_role = keycloak.Role("user-role",
    realm_id=my_realm.id,
    name="user",
)

admin_role = keycloak.Role("admin-role",
    realm_id=my_realm.id,
    name="admin",
)

# Create a user. This user will be able to authenticate and be authorized to perform actions according to their role.
my_user = keycloak.User("my-user",
    realm_id=my_realm.id,
    username="exampleuser",
    email="user@example.com",
    enabled=True,
)

# Assign roles to the user.
my_user_roles = keycloak.UserRoles("my-user-roles",
    realm_id=my_realm.id,
    user_id=my_user.id,
    role_ids=[user_role.id, admin_role.id], # The user will have both 'user' and 'admin' roles.
)

# Create a group. Groups can be helpful to manage roles and permissions for a set of users.
my_group = keycloak.Group("my-group",
    realm_id=my_realm.id,
    name="examplegroup",
)

# Assign roles to the group. All users in the group will inherit these roles.
my_group_roles = keycloak.GroupRoles("my-group-roles",
    realm_id=my_realm.id,
    group_id=my_group.id,
    role_ids=[user_role.id], # The group is granted only the 'user' role.
)

# Outputs that could be useful to store or to provide to the microservices.
pulumi.export("realm_id", my_realm.id)
pulumi.export("client_id", my_client.id)
pulumi.export("user_role_id", user_role.id)
pulumi.export("admin_role_id", admin_role.id)
pulumi.export("group_id", my_group.id)
```

In this program:

- We create a realm that acts like a namespace for the Keycloak setup.
- We define a client, which represents an application that will be using Keycloak as the authentication and authorization server.
- We create user and admin roles that will be used to grant different levels of access.
- We create a user and assign our previously created roles to the user.
- Finally, we create a group, assign a role to the group, and export important IDs that might be used by the microservices for validation and authentication.

This code is meant to be run within a Pulumi application. It interacts with the Keycloak API through the Pulumi Keycloak provider to create and manage resources. Once this infrastructure is in place, your microservices can be updated to interact with Keycloak using its APIs or through client libraries.

After creating these resources, any microservice that you deploy can authenticate through Keycloak and receive tokens which have claims reflecting the roles that each user has. It allows for flexible and centralized control over roles and permissions in a microservice architecture.