Apply fault injection

Apply a fault injection policy to the ratings service to delay requests and simulate network issues or an overloaded service. A delay simulates an overloaded upstream service or network issues, and can help you build more resilient apps.

  1. Verify that you can successfully send requests to the ratings app from within the mesh.

    Use the kubectl debug command to create an ephemeral curl container in the deployment. This way, the curl container inherits any permissions from the app that you want to test. If you don’t run Kubernetes 1.23 or later, you can deploy a separate curl pod or manually add the curl container as shown in the other tab.

      kubectl --context ${REMOTE_CONTEXT1} -n bookinfo debug -i pods/$(kubectl get pod --context ${REMOTE_CONTEXT1} -l app=ratings -A -o jsonpath='{.items[0].metadata.name}') --image=curlimages/curl -- curl http://ratings:9080/ratings/1

    Example output:

      {"id":1,"ratings":{"Reviewer1":5,"Reviewer2":4}}

    If the output has an error about EphemeralContainers, see Ephemeral containers don’t work when testing Bookinfo.

    Create a temporary curl pod in the bookinfo namespace, so that you can test the app setup. You can also use this method in Kubernetes 1.23 or later, but an ephemeral container might be simpler.

    1. Create the curl pod.

        kubectl run -it -n bookinfo --context $REMOTE_CONTEXT1 curl \
  --image=curlimages/curl:7.73.0 --rm  -- sh

    2. Send a request to the ratings app.

        curl http://ratings:9080/ratings/1

      Example output:

        {"id":1,"ratings":{"Reviewer1":5,"Reviewer2":4}}

    3. Exit the temporary pod. The pod deletes itself.

        exit

  2. Create a fault injection policy to delay responses from the ratings app by 10 seconds, and a route table specifically for testing access to the ratings app.

      kubectl apply --context $MGMT_CONTEXT -f- <<EOF
apiVersion: resilience.policy.gloo.solo.io/v2
kind: FaultInjectionPolicy
metadata:
  name: faultinjection-basic-delay
  namespace: bookinfo
spec:
  applyToRoutes:
    - route:
        labels:
          route: ratings
  config:
    delay:
      fixedDelay: 10s
---
apiVersion: networking.gloo.solo.io/v2
kind: RouteTable
metadata:
  name: ratings-rt
  namespace: bookinfo
spec:
  hosts:
  - ratings
  http:
  - forwardTo:
      destinations:
      - ref:
          name: ratings
          namespace: bookinfo
    labels:
      route: ratings
  workloadSelectors:
  - {}
EOF

  3. Send another request to the ratings app by using the same method as in step 1. Note that this time, the app’s response is delayed due to the fault injection.

Explore the UI

Use the Gloo UI to evaluate the health and efficiency of your service mesh.

  1. Open the Gloo UI. The Gloo UI is served from the gloo-mesh-ui service on port 8090. You can connect by using the meshctl or kubectl CLIs.

  • meshctl: For more information, see the CLI documentation.
      meshctl dashboard
  • kubectl:
    1. Port-forward the gloo-mesh-ui service on 8090.
        kubectl port-forward -n gloo-mesh svc/gloo-mesh-ui 8090:8090
    2. Open your browser and connect to http://localhost:8090.

  1. Review the Dashboard page, which presents an at-a-glance look at the health of workspaces and clusters that make up your Gloo setup.

    • In the Workspaces pane, you can review the workspace that was automatically created for you in your Gloo setup.
    • In the Clusters pane, you can review the workload clusters that are currently connected to your Gloo setup.
    Figure: Overview UI screenshot
    Figure: Overview UI screenshot

  2. Verify the details of the fault injection policy that you created in the previous section.

    1. Click the Resources tab to open the Solo resources page.
    2. In the row for your policy, faultinjection-basic-delay, click View Policy.
    3. Review the details of the policy, such as the ratings route that it applies to.
    4. Click View YAML.
    5. Scroll to the end of the YAML output to verify that the policy has a state of ACCEPTED.

Next steps

Now that you have Gloo Mesh Enterprise and Istio up and running, check out some of the following resources to learn more about Gloo Mesh and expand your service mesh capabilities.

Gloo Mesh Enterprise:

Istio: Now that you have Gloo Mesh Enterprise and Istio installed, you can use Gloo to manage your Istio service mesh resources. You don’t need to directly configure any Istio resources going forward.

Help and support:

Cleanup

You can optionally remove the resources that you set up as part of this guide.

  1. Delete the fault injection policy and testing route table.

      kubectl delete FaultInjectionPolicy faultinjection-basic-delay -n bookinfo --context $MGMT_CONTEXT
kubectl delete RouteTable ratings-rt -n bookinfo --context $MGMT_CONTEXT

  2. If you no longer need this quick-start Gloo Mesh environment, you can follow the steps in the uninstall guide.