Simulate HTTP faults

This document describes how to simulate HTTP faults by creating HTTPChaos experiments in Chaos Mesh.

HTTPChaos introduction

HTTPChaos is a fault type provided by Chaos Mesh. By creating HTTPChaos experiments, you can simulate the fault scenarios of the HTTP server during the HTTP request and response processing. Currently, HTTPChaos supports simulating the following fault types:

• abort: interrupts server connection
• delay: injects latency into the target process
• replace: replaces part of content in HTTP request or response messages
• patch: adds additional content to HTTP request or response messages

HTTPChaos supports combinations of different fault types. If you have configured multiple HTTP fault types at the same time when creating HTTPChaos experiments, the order set to inject the faults when the experiments start running is abort -> delay -> replace -> patch. When the abort fault cause short circuits, the connection will be directly interrupted.

For the detailed description of HTTPChaos configuration, see Field description below.

Notes

Before injecting the faults supported by HTTPChaos, note the followings:

• There is no control manager of Chaos Mesh running on the target Pod.
• HTTPS accesses should be disabled, because injecting HTTPS connections is not supported currently.
• For HTTPChaos injection to take effect, the client should avoid reusing TCP socket. This is because HTTPChaos does not affect the HTTP requests that are sent via TCP socket before the fault injection.
• Use non-idempotent requests (such as most of the POST requests) with caution in production environments. If such requests are used, the target service may not return to normal status by repeating requests after the fault injection.

Create experiments

Currently, Chaos Mesh only supports using YAML configuration files to create HTTPChaos experiments. In the YAML files, you can simulate either one HTTP fault type or a combination of different HTTP fault types.

Example of abort

1. Write the experimental configuration to the http-abort-failure.yaml file as the example below:

   apiVersion: chaos-mesh.org/v1alpha1
   kind: HTTPChaos
   metadata:
     name: test-http-chaos
   spec:
     mode: all
     selector:
       labelSelectors:
         app: nginx
     target: Request
     port: 80
     method: GET
     path: /api
     abort: true
     duration: 5m
     scheduler:
       cron: '@every 10m'

   Based on this configuration example, every 10 minutes, Chaos Mesh will inject the abort fault into the specified pod for 5 minutes. During the fault injection, the GET requests sent through port 80 in the /api path of the target Pod will be interrupted.

2. After the configuration file is prepared, use kubectl to create the experiment:

   kubectl apply -f ./http-abort-failure.yaml

Example of fault combinations

1. Write the experimental configuration to http-failure.yaml file as the example below:

   apiVersion: chaos-mesh.org/v1alpha1
   kind: HTTPChaos
   metadata:
     name: test-http-chaos
   spec:
     mode: all
     selector:
       labelSelectors:
         app: nginx
     target: Request
     port: 80
     method: GET
     path: /api/*
     delay: 10s
     replace:
       path: /api/v2/
       method: DELETE
     patch:
       headers:
         - ['Token', '<one token>']
         - ['Token', '<another token>']
       body:
         type: JSON
         value: '{"foo": "bar"}'
     duration: 5m
     scheduler:
       cron: '@every 10m'

   Based on this configuration example, Chaos Mesh will inject the delay fault, replace fault, and patch fault consecutively.

2. After the configuration file is prepared, use kubectl to create the experiment:

   kubectl apply -f ./http-failure.yaml

Field description

Description for common fields

Common fields are meaningful when the target of fault injection is Request or Response.

Description for target-related fields

Request-related fields

The Request field is a meaningful when the target set to Request during the fault injection.

Respond-related fields

The Response is a meaningful when the target set to Response during the fault injection.

Local debugging

If you are not sure of the effects of certain fault injections, you can also test the corresponding features locally using rs-tproxy. Chaos Mesh also provides HTTPChaos by using rs-tproxy.