EC2 stop by ID

EC2 stop by ID stops an EC2 instance using the provided instance ID or list of instance IDs.

• It brings back the instance after a specific duration.
• It checks the performance of the application (or process) running on the EC2 instance.
• When the MANAGED_NODEGROUP environment variable is enabled, the fault will not try to start the instance after chaos. Instead, it checks for the addition of a new node instance to the cluster.

Usage

View fault usage

This fault determines the resilience of an application to unexpected halts in the EC2 instance by validating its failover capabilities.

Prerequisites

• Kubernetes >= 1.17
• Access to start and stop an EC2 instance in AWS.
• Kubernetes secret that has AWS access configuration(key) in the CHAOS_NAMESPACE. Below is the 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

• If you change the secret key name (from cloud_config.yml), ensure that you update the AWS_SHARED_CREDENTIALS_FILE environment variable on experiment.yaml with the new name.

WARNING

If the target EC2 instance is a part of a managed node group, drain the target node of any application running on it. Isolate the target node before running the fault so that the fault pods are not scheduled on it.

Permissions required

Here is an example AWS policy to execute the fault.

View policy for the fault

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "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 EC2 instance should be in a healthy state.

Fault tunables

Fault tunables

Mandatory fields

Variables	Description	Notes
EC2_INSTANCE_ID	Instance ID of the target EC2 instance. Multiple IDs can also be provided as a comma(,) separated values.	Multiple IDs can be provided as `id1,id2`.
REGION	The region name of the target instance.

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.
MANAGED_NODEGROUP	Set to enable if the target instance is the part of self-managed nodegroups.	Defaults to disable.
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, 30s.

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.

Stop Instances By ID

It contains a comma-separated list of instance IDs subjected to EC2 stop chaos. You can tune it using the EC2_INSTANCE_ID environment variable.

You can tune it using the following example.

# contains the instance id, to be terminated/stopped
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: ec2-terminate-by-id
    spec:
      components:
        env:
        # ID of the EC2 instance
        - name: EC2_INSTANCE_ID
          value: 'instance-1'
        # region for the EC2 instance
        - name: REGION
          value: 'us-east-1'