Configure fault injection - Alibaba Cloud Service Mesh - Alibaba Cloud Documentation Center

Fault injection is a testing method that deliberately creates defects in a service to improve fault tolerance, discover client-side bugs, or identify potential faults. You can use virtual services to conduct fault injection testing at the application layer. This topic describes how to configure fault injection.

Prerequisites

The preparations are completed, and the HTTPBin and sleep services are deployed. For more information, see Preparations.

Procedure

Check whether the service configurations take effect.
1. Use kubectl to connect to the Container Service for Kubernetes (ACK) cluster based on the information in the kubeconfig file, and then run the following command to enable bash for the sleep service:
```
kubectl exec -it deploy/sleep -- sh
```
2. Run the following command to send a request to the HTTPBin service:
```
curl -I httpbin:8000
```
  Expected output:
```
HTTP/1.1 200 OK
Server: gunicorn/19.9.0
Date: Mon, 28 Aug 2023 06:15:30 GMT
Connection: keep-alive
Content-Type: text/html; charset=utf-8
Content-Length: 9593
Access-Control-Allow-Origin: *
Access-Control-Allow-Credentials: true
```
Use the istioctl tool to run the following command to deploy a Layer 7 waypoint proxy for the HTTPBin service:
```
istioctl x waypoint apply --service-account httpbin
```

Use the following content to create a virtual service, configure a traffic rule for the HTTPBin service, and inject faults. For more information, see Manage virtual services.

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: httpbin-vs
  namespace: default
spec:
  hosts:
    - httpbin
  http:
    - fault:
        delay:
          fixedDelay: 5s
          percentage:
            value: 100
      route:
        - destination:
            host: httpbin

Check whether the configurations take effect.
1. Use kubectl to connect to the ACK cluster based on the information in the kubeconfig file, and then run the following command to enable bash for the sleep service:
```
kubectl exec -it deploy/sleep -- sh
```
2. Run the following command to send a request to the HTTPBin service:
```
curl -I httpbin:8000
```
  Expected output:
```
HTTP/1.1 200 OK
server: istio-envoy
date: Fri, 11 Aug 2023 06:15:26 GMT
content-type: text/html; charset=utf-8
content-length: 9593
access-control-allow-origin: *
access-control-allow-credentials: true
x-envoy-upstream-service-time: 2
```
  The output indicates that the response is delayed for 5 seconds and the fault injection is successful.