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User guide: Simple pattern-matching authorization policies

Write simple authorization rules based on JSON patterns matched against Authorino's Authorization JSON; check contextual information of the request, validate JWT claims, cross metadata fetched from external sources, etc.

Authorino capabilities featured in this guide:

Authorino provides a built-in authorization module to check simple pattern-matching rules against the Authorization JSON. This is an alternative to OPA when all you want is to check for some simple rules, without complex logics, such as match the value of a JWT claim.

Check out as well the user guide about OpenID Connect Discovery and authentication with JWTs.

For further details about Authorino features in general, check the docs.


Requirements

  • Kubernetes server with permissions to install cluster-scoped resources (operator, CRDs and RBAC)
  • Identity Provider (IdP) that implements OpenID Connect authentication and OpenID Connect Discovery (e.g. Keycloak)
  • jq, to extract parts of JSON responses

If you do not own a Kubernetes server already and just want to try out the steps in this guide, you can create a local containerized cluster by executing the command below. In this case, the main requirement is having Kind installed, with either Docker or Podman.

kind create cluster --name authorino-tutorial

Deploy the identity provider and authentication server by executing the command below. For the examples in this guide, we are going to use a Keycloak server preloaded with all required realm settings.

kubectl create namespace keycloak
kubectl -n keycloak apply -f https://raw.githubusercontent.com/kuadrant/authorino-examples/main/keycloak/keycloak-deploy.yaml

The next steps walk you through installing Authorino, deploying and configuring a sample service called Talker API to be protected by the authorization service.

Using Kuadrant

If you are a user of Kuadrant and already have your workload cluster configured and sample service application deployed, as well as your Gateway API network resources applied to route traffic to your service, skip straight to step ❺.

At step ❺, instead of creating an AuthConfig custom resource, create a Kuadrant AuthPolicy one. The schema of the AuthConfig's spec matches the one of the AuthPolicy's, except spec.host, which is not available in the Kuadrant AuthPolicy. Host names in a Kuadrant AuthPolicy are inferred automatically from the Kubernetes network object referred in spec.targetRef and route selectors declared in the policy.

For more about using Kuadrant to enforce authorization, check out Kuadrant auth.

❶ Install the Authorino Operator (cluster admin required)

The following command will install the Authorino Operator in the Kubernetes cluster. The operator manages instances of the Authorino authorization service.

curl -sL https://raw.githubusercontent.com/Kuadrant/authorino-operator/main/utils/install.sh | bash -s

❷ Deploy Authorino

The following command will request an instance of Authorino as a separate service1 that watches for AuthConfig resources in the default namespace2, with TLS disabled3.

kubectl apply -f -<<EOF
apiVersion: operator.authorino.kuadrant.io/v1beta1
kind: Authorino
metadata:
  name: authorino
spec:
  listener:
    tls:
      enabled: false
  oidcServer:
    tls:
      enabled: false
EOF

❸ Deploy the Talker API

The Talker API is a simple HTTP service that echoes back in the response whatever it gets in the request. We will use it in this guide as the sample service to be protected by Authorino.

kubectl apply -f https://raw.githubusercontent.com/kuadrant/authorino-examples/main/talker-api/talker-api-deploy.yaml

❹ Setup Envoy

The following bundle from the Authorino examples deploys the Envoy proxy and configuration to wire up the Talker API behind the reverse-proxy, with external authorization enabled with the Authorino instance.4

kubectl apply -f https://raw.githubusercontent.com/kuadrant/authorino-examples/main/envoy/envoy-notls-deploy.yaml

The command above creates an Ingress with host name talker-api.127.0.0.1.nip.io. If you are using a local Kubernetes cluster created with Kind, forward requests from your local port 8000 to the Envoy service running inside the cluster:

kubectl port-forward deployment/envoy 8000:8000 2>&1 >/dev/null &

❺ Create an AuthConfig

Create an Authorino AuthConfig custom resource declaring the auth rules to be enforced.

The email-verified-only authorization policy ensures that users consuming the API from a given network (IP range 192.168.1/24) must have their emails verified.

The email_verified claim is a property of the identity added to the JWT by the OpenID Connect issuer.

The implementation relies on the X-Forwarded-For HTTP header to read the client's IP address.

Kuadrant users – Remember to create an AuthPolicy instead of an AuthConfig. For more, see Kuadrant auth. 
kubectl apply -f -<<EOF
apiVersion: authorino.kuadrant.io/v1beta3
kind: AuthConfig
metadata:
  name: talker-api-protection
spec:
  hosts:
  - talker-api.127.0.0.1.nip.io
  authentication:
    "keycloak-kuadrant-realm":
      jwt:
        issuerUrl: http://keycloak.keycloak.svc.cluster.local:8080/realms/kuadrant
  authorization:
    "email-verified-only":
      when:
      - selector: "context.request.http.headers.x-forwarded-for.@extract:{\"sep\": \",\"}"
        operator: matches
        value: 192\\.168\\.1\\.\\d+
      patternMatching:
        patterns:
        - selector: auth.identity.email_verified
          operator: eq
          value: "true"
EOF

Check out the docs for information about semantics and operators supported by the JSON pattern-matching authorization feature, as well the common feature JSON paths for reading from the Authorization JSON, including the description of the string modifier @extract used above. Check out as well the common feature Conditions about skipping parts of an AuthConfig in the auth pipeline based on context.

❻ Obtain an access token and consume the API

Obtain an access token and consume the API as Jane (email verified)

Obtain an access token with the Keycloak server for Jane:

The AuthConfig deployed in the previous step is suitable for validating access tokens requested inside the cluster. This is because Keycloak's iss claim added to the JWTs matches always the host used to request the token and Authorino will later try to match this host to the host that provides the OpenID Connect configuration.

Obtain an access token from within the cluster for the user Jane, whose e-mail has been verified:

ACCESS_TOKEN=$(kubectl run token --attach --rm --restart=Never -q --image=curlimages/curl -- http://keycloak.keycloak.svc.cluster.local:8080/realms/kuadrant/protocol/openid-connect/token -s -d 'grant_type=password' -d 'client_id=demo' -d 'username=jane' -d 'password=p' -d 'scope=openid' | jq -r .access_token)

If your Keycloak server is reachable from outside the cluster, feel free to obtain the token directly. Make sure the host name set in the OIDC issuer endpoint in the AuthConfig matches the one used to obtain the token and is as well reachable from within the cluster.

As Jane, consume the API outside the area where the policy applies:

curl -H "Authorization: Bearer $ACCESS_TOKEN" \
     -H 'X-Forwarded-For: 123.45.6.78' \
     http://talker-api.127.0.0.1.nip.io:8000/hello
# HTTP/1.1 200 OK

As Jane, consume the API inside the area where the policy applies:

curl -H "Authorization: Bearer $ACCESS_TOKEN" \
     -H 'X-Forwarded-For: 192.168.1.10' \
     http://talker-api.127.0.0.1.nip.io:8000/hello
# HTTP/1.1 200 OK

Obtain an access token and consume the API as Peter (email NOT verified)

Obtain an access token with the Keycloak server for Peter:

ACCESS_TOKEN=$(kubectl run token --attach --rm --restart=Never -q --image=curlimages/curl -- http://keycloak.keycloak.svc.cluster.local:8080/realms/kuadrant/protocol/openid-connect/token -s -d 'grant_type=password' -d 'client_id=demo' -d 'username=peter' -d 'password=p' -d 'scope=openid' | jq -r .access_token)

As Peter, consume the API outside the area where the policy applies:

curl -H "Authorization: Bearer $ACCESS_TOKEN" \
     -H 'X-Forwarded-For: 123.45.6.78' \
     http://talker-api.127.0.0.1.nip.io:8000/hello
# HTTP/1.1 200 OK

As Peter, consume the API inside the area where the policy applies:

curl -H "Authorization: Bearer $ACCESS_TOKEN" \
     -H 'X-Forwarded-For: 192.168.1.10' \
     http://talker-api.127.0.0.1.nip.io:8000/hello -i
# HTTP/1.1 403 Forbidden
# x-ext-auth-reason: Unauthorized

Cleanup

If you have started a Kubernetes cluster locally with Kind to try this user guide, delete it by running:

kind delete cluster --name authorino-tutorial

Otherwise, delete the resources created in each step:

kubectl delete authconfig/talker-api-protection
kubectl delete -f https://raw.githubusercontent.com/kuadrant/authorino-examples/main/envoy/envoy-notls-deploy.yaml
kubectl delete -f https://raw.githubusercontent.com/kuadrant/authorino-examples/main/talker-api/talker-api-deploy.yaml
kubectl delete namespace keycloak
kubectl delete authorino/authorino

To uninstall the Authorino Operator and manifests (CRDs, RBAC, etc), run:

kubectl delete -f https://raw.githubusercontent.com/Kuadrant/authorino-operator/main/config/deploy/manifests.yaml

Footnotes

  1. In contrast to a dedicated sidecar of the protected service and other architectures. Check out Architecture > Topologies for all options. ↩

  2. namespaced reconciliation mode. See Cluster-wide vs. Namespaced instances. ↩

  3. For other variants and deployment options, check out Getting Started, as well as the Authorino CRD specification. ↩

  4. For details and instructions to setup Envoy manually, see Protect a service > Setup Envoy in the Getting Started page. If you are running your ingress gateway in Kubernetes and wants to avoid setting up and configuring your proxy manually, check out Kuadrant. ↩