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ECS instance stop

ECS instance stop induces stress on an AWS ECS cluster. It derives the instance under chaos from the ECS cluster.

  • It causes EC2 instance to stop and get deleted from the ECS cluster for a specific duration.

ECS Instance Stop

tip

This experiment induces chaos within a container and depends on an EC2 instance. Typically, these are prefixed with "ECS container" and involve direct interaction with the EC2 instances hosting the ECS containers.

Usage​

View fault usage
EC2 instance stop breaks the agent that manages the task container on ECS cluster, thereby impacting its delivery. Killing the EC2 instance disrupts the performance of the task container.

Prerequisites​

  • Kubernetes >= 1.17
  • Adequate AWS access to stop and start an EC2 instance.
  • Create a Kubernetes secret that has the AWS access configuration(key) in the CHAOS_NAMESPACE. Below is a sample secret file:
apiVersion: v1
kind: Secret
metadata:
  name: cloud-secret
type: Opaque
stringData:
  cloud_config.yml: |-
    # Add the cloud AWS credentials respectively
    [default]
    aws_access_key_id = XXXXXXXXXXXXXXXXXXX
    aws_secret_access_key = XXXXXXXXXXXXXXX

  • It is recommended to use the same secret name, i.e. cloud-secret. Otherwise, you will need to update the AWS_SHARED_CREDENTIALS_FILE environment variable in the fault template and you may be unable to use the default health check probes.

  • Refer to AWS Named Profile For Chaos to know how to use a different profile for AWS faults.

Permissions required​

Here is an example AWS policy to execute the fault.

View policy for the fault
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": [
                "ecs:ListContainerInstances",
                "ecs:DescribeContainerInstances"

            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:StartInstances",
                "ec2:StopInstances",
                "ec2:DescribeInstanceStatus",
                "ec2:DescribeInstances"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "autoscaling:DescribeAutoScalingInstances"
            ],
            "Resource": "*"
        }
    ]
}

Refer to the superset permission/policy to execute all AWS faults.

Default validations​

The ECS container instance should be in a healthy state.

Fault tunables​

Fault tunables

Mandatory fields

Variables Description Notes
CLUSTER_NAME Name of the target ECS cluster For example, cluster-1
REGION The region name of the target ECS cluster For example, us-east-1

Optional fields

Variables Description Notes
TOTAL_CHAOS_DURATION Duration that you specify, through which chaos is injected into the target resource (in seconds). Defaults to 30s.
CHAOS_INTERVAL The interval (in sec) between successive instance termination. Defaults to 30s
AWS_SHARED_CREDENTIALS_FILE Provide the path for aws secret credentials Defaults to /tmp/cloud_config.yml
EC2_INSTANCE_ID Provide the target instance ID from ECS cluster If not provided will select randomly
SEQUENCE It defines sequence of chaos execution for multiple instance Defaults to parallel. Supports serial sequence as well.
RAMP_TIME Period to wait before and after injecting chaos (in seconds). For example, 30

Fault examples​

Common and AWS-specific tunables​

Refer to the common attributes and AWS-specific tunables to tune the common tunables for all faults and aws specific tunables.

ECS Instance Stop​

It stops the instance of an ECS cluster for a certain chaos duration. We can provide the EC2 instance ID using EC2_INSTANCE_ID ENVs as well. If not provided it will select randomly.

Use the following example to tune it:

# stops the agent of an ECS cluster
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  annotationCheck: "false"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: ecs-instance-stop
    spec:
      components:
        env:
        # provide the name of ECS cluster
        - name: CLUSTER_NAME
          value: 'demo'
        - name: EC2_INSTANCE_ID
          value: 'us-east-2'
        - name: TOTAL_CHAOS_DURATION
          VALUE: '60'