Basic rate limit policy

Apply a basic rate limiting policy.

Control the rate of requests to destinations within the service mesh. The following example shows you how to create a basic rate limit policy that applies to a destination, based on a generic key.

For more in-depth examples of the Envoy and Set-style rate limiting APIs, see More rate limit policy examples.

If you import or export resources across workspaces, your policies might not apply. For more information, see Import and export policies.

Before you begin

This guide assumes that you use the same names for components like clusters, workspaces, and namespaces as in the getting started. If you have different names, make sure to update the sample configuration files in this guide.

Complete the multicluster getting started guide to set up the following testing environment.
- Three clusters along with environment variables for the clusters and their Kubernetes contexts.
- The Gloo meshctl CLI, along with other CLI tools such as kubectl and istioctl.
- The Gloo management server in the management cluster, and the Gloo agents in the workload clusters.
- Istio installed in the workload clusters.
- A simple Gloo workspace setup.
Install Bookinfo and other sample apps.
Make sure that the rate limiting service is installed and running. If not, install the rate limiting service.
```
kubectl get pods &ndash;context $REMOTE_CONTEXT1 -A -l app=rate-limiter
```
To use rate limiting policies, you must create the required RateLimitServerConfig, RateLimitServerSettings, and RateLimitClientConfig resources. To create these resources you can either follow the Rate limit server setup guide, or use the example resources in step 2 of the Verify rate limit policies section.

Configure rate limit policies

You can apply a rate limit policy at the destination level. For more information, see Applying policies.

This policy currently does not support selecting VirtualDestinations as a destination.

You cannot apply this policy to a route that already has a redirect, rewrite, or direct response action. Keep in mind that these actions might not be explicitly defined in the route configuration. For example, invalid routes are automatically replaced with a direct response action, such as when the backing destination is wrong. First, verify that your route configuration is correct. Then, decide whether to apply the policy. To apply the policy, remove any redirect, rewrite, or direct response actions. To keep the actions and not apply the policy, change the route labels of either the policy or the route.

Review the following sample configuration files. Continue to the Verify rate limit policies section for example steps on how to check that rate limiting is working.

apiVersion: trafficcontrol.policy.gloo.solo.io/v2
kind: RateLimitPolicy
metadata:
  name: rl-policy
  namespace: bookinfo
spec:
  applyToDestinations:
  - port:
      number: 9080
    selector:
      labels:
        app: reviews
  config:
    ratelimitClientConfig:
      name: rl-client-config
    ratelimitServerConfig:
      name: rl-server-config
      namespace: gloo-mesh
    serverSettings:
      name: rl-server

Review the following table to understand this configuration.

Setting Description

applyToDestinations Use labels to apply the policy to destinations. Destinations might be a Kubernetes service, VirtualDestination, or ExternalService (if supported by the policy). If you do not specify any destinations or routes, the policy applies to all destinations in the workspace by default. If you do not specify any destinations but you do specify a route, the policy applies to the route but to no destinations.

config The ratelimitServerConfig is required. The serverSettings and ratelimitClientConfig are optional, and can be added manually in the policy. In this example, the rate limit policy refers to the client config, server config, and server settings that you downloaded before you began. For more information, see Rate limit server setup.

Setting	Description
`applyToDestinations`	Use labels to apply the policy to destinations. Destinations might be a Kubernetes service, VirtualDestination, or ExternalService (if supported by the policy). If you do not specify any destinations or routes, the policy applies to all destinations in the workspace by default. If you do not specify any destinations but you do specify a route, the policy applies to the route but to no destinations.
`config`	The `ratelimitServerConfig` is required. The `serverSettings` and `ratelimitClientConfig` are optional, and can be added manually in the policy. In this example, the rate limit policy refers to the client config, server config, and server settings that you downloaded before you began. For more information, see Rate limit server setup.

Verify rate limit policies

Create a rate limit server config with the rate limiting rules that the server accepts. For more information, see Rate limit server setup. Note: Change cluster-1 as needed to your cluster’s actual name (value of $CLUSTER_NAME).

kubectl apply -f - << EOF
apiVersion: admin.gloo.solo.io/v2
kind: RateLimitServerConfig
metadata:
  name: rl-server-config
  namespace: gloo-mesh
spec:
  destinationServers:
  - port:
      number: 8083
    ref:
      cluster: cluster-1
      name: rate-limiter
      namespace: gloo-mesh
  raw:
    descriptors:
    - key: generic_key
      rateLimit:
        requestsPerUnit: 1
        unit: DAY
      value: counter
EOF

Create a rate limit server settings resource to control how clients connect to the rate limit server. For more information, see Rate limit server setup. Note: Change cluster-1 as needed to your cluster’s actual name (value of $CLUSTER_NAME).

kubectl apply -f - << EOF
apiVersion: admin.gloo.solo.io/v2
kind: RateLimitServerSettings
metadata:
  name: rl-server
  namespace: bookinfo
spec:
  destinationServer:
    port:
      number: 8083
    ref:
      cluster: cluster-1
      name: rate-limiter
      namespace: gloo-mesh
EOF

kubectl apply -f - << EOF apiVersion: trafficcontrol.policy.gloo.solo.io/v2 kind: RateLimitClientConfig metadata: name: rl-client-config namespace: bookinfo spec: raw: rateLimits: - actions: - genericKey: descriptorValue: counter limit: dynamicMetadata: metadataKey: key: envoy.filters.http.ext_authz path: - key: opa_auth - key: rateLimit EOF

kubectl apply -f - << EOF apiVersion: trafficcontrol.policy.gloo.solo.io/v2 kind: RateLimitPolicy metadata: name: rl-policy namespace: bookinfo spec: applyToDestinations: - port: number: 9080 selector: labels: app: reviews config: ratelimitClientConfig: name: rl-client-config ratelimitServerConfig: name: rl-server-config namespace: gloo-mesh serverSettings: name: rl-server EOF

Cleanup

kubectl &ndash;context $REMOTE_CONTEXT1 -n gloo-mesh delete RateLimitServerConfig rl-server-config
kubectl &ndash;context $REMOTE_CONTEXT1 -n bookinfo delete RateLimitServerSettings rl-server
kubectl &ndash;context $REMOTE_CONTEXT1 -n bookinfo delete RateLimitClientConfig rl-client-config
kubectl &ndash;context $REMOTE_CONTEXT1 -n bookinfo delete RateLimitPolicy rl-policy