ExperimentTemplate

Source: src/AWS/FIS/ExperimentTemplate.ts

An AWS Fault Injection Service (FIS) experiment template — a reusable definition of a chaos-engineering experiment: the targets to disrupt, the fault actions to run against them, and the stop conditions that abort a runaway experiment.

Creating a template is free and does not disrupt any resources — faults are only injected when an experiment is explicitly started from the template.

Creating Experiment Templates

Stop EC2 instances selected by tag

import * as AWS from "alchemy/AWS";

const role = yield* AWS.IAM.Role("FisRole", {
  assumeRolePolicyDocument: {
    Version: "2012-10-17",
    Statement: [{
      Effect: "Allow",
      Principal: { Service: "fis.amazonaws.com" },
      Action: ["sts:AssumeRole"],
    }],
  },
  managedPolicyArns: [
    "arn:aws:iam::aws:policy/service-role/AWSFaultInjectionSimulatorEC2Access",
  ],
});

const template = yield* AWS.FIS.ExperimentTemplate("StopInstances", {
  description: "Stop one tagged instance for two minutes",
  roleArn: role.roleArn,
  targets: {
    Instances: {
      resourceType: "aws:ec2:instance",
      resourceTags: { ChaosReady: "true" },
      selectionMode: "COUNT(1)",
    },
  },
  actions: {
    StopInstances: {
      actionId: "aws:ec2:stop-instances",
      parameters: { startInstancesAfterDuration: "PT2M" },
      targets: { Instances: "Instances" },
    },
  },
});

Stop condition backed by a CloudWatch alarm

const template = yield* AWS.FIS.ExperimentTemplate("GuardedExperiment", {
  roleArn: role.roleArn,
  targets: {
    Instances: {
      resourceType: "aws:ec2:instance",
      resourceTags: { ChaosReady: "true" },
      selectionMode: "ALL",
    },
  },
  actions: {
    StopInstances: {
      actionId: "aws:ec2:stop-instances",
      targets: { Instances: "Instances" },
    },
  },
  stopConditions: [
    {
      source: "aws:cloudwatch:alarm",
      value: alarmArn,
    },
  ],
});

Wait action sequenced after a fault

const template = yield* AWS.FIS.ExperimentTemplate("SequencedExperiment", {
  roleArn: role.roleArn,
  actions: {
    Wait: {
      actionId: "aws:fis:wait",
      parameters: { duration: "PT1M" },
    },
    WaitAgain: {
      actionId: "aws:fis:wait",
      parameters: { duration: "PT1M" },
      startAfter: ["Wait"],
    },
  },
});