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User guide: Authenticated rate limiting (with Envoy Dynamic Metadata)

Provide Envoy with dynamic metadata about the external authorization process to be injected into the rate limiting filter.

Authorino capabilities featured in this guide:

Dynamic JSON objects built out of static values and values fetched from the Authorization JSON can be wrapped to be returned to the reverse-proxy as Envoy Well Known Dynamic Metadata content. Envoy can use those to inject data returned by the external authorization service into the other filters, such as the rate limiting filter.

Check out as well the user guides about Injecting data in the request and Authentication with API keys.

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)

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


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 ❻.

At step ❻, 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 Limitador

Limitador is a lightweight rate limiting service that can be used with Envoy.

On this bundle, we will deploy Limitador pre-configured to limit requests to the talker-api domain up to 5 requests per interval of 60 seconds per user_id. Envoy will be configured to recognize the presence of Limitador and activate it on requests to the Talker API.

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

❹ 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

❺ 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 &

❻ Create an AuthConfig

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

An annotation auth-data/username will be read from the Kubernetes API Key secret and passed as dynamic metadata { "ext_auth_data": { "username": «annotations.auth-data/username» } }.

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:
    "friends":
      apiKey:
        selector:
          matchLabels:
            group: friends
      credentials:
        authorizationHeader:
          prefix: APIKEY
  response:
    success:
      dynamicMetadata:
        "rate-limit":
          json:
            properties:
              "username":
                expression: auth.identity.metadata.annotations['auth-data/username']
          key: ext_auth_data # how this bit of dynamic metadata from the ext authz service is named in the Envoy config
EOF

Check out the docs about using Common Expression Language (CEL) for reading from the Authorization JSON.

❼ Create the API keys

For user John:

kubectl apply -f -<<EOF
apiVersion: v1
kind: Secret
metadata:
  name: api-key-1
  labels:
    authorino.kuadrant.io/managed-by: authorino
    group: friends
  annotations:
    auth-data/username: john
stringData:
  api_key: ndyBzreUzF4zqDQsqSPMHkRhriEOtcRx
type: Opaque
EOF

For user Jane:

kubectl apply -f -<<EOF
apiVersion: v1
kind: Secret
metadata:
  name: api-key-2
  labels:
    authorino.kuadrant.io/managed-by: authorino
    group: friends
  annotations:
    auth-data/username: jane
stringData:
  api_key: 7BNaTmYGItSzXiwQLNHu82+x52p1XHgY
type: Opaque
EOF

❽ Consume the API

As John:

curl -H 'Authorization: APIKEY ndyBzreUzF4zqDQsqSPMHkRhriEOtcRx' http://talker-api.127.0.0.1.nip.io:8000/hello -i
# HTTP/1.1 200 OK

Repeat the request a few more times within the 60-second time window, until the response status is 429 Too Many Requests.

While the API is still limited to John, send requests as Jane:

curl -H 'Authorization: APIKEY 7BNaTmYGItSzXiwQLNHu82+x52p1XHgY' http://talker-api.127.0.0.1.nip.io:8000/hello -i
# HTTP/1.1 200 OK

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 secret/api-key-1
kubectl delete secret/api-key-2
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 -f https://raw.githubusercontent.com/kuadrant/authorino-examples/main/limitador/limitador-deploy.yaml
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

  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. ↩