EC2 process kill

EC2 process kill fault kills the target processes running on an EC2 instance.

• It checks the performance of the application/process running on the EC2 instance(s).

Usage

View fault usage

This fault disrupts the application critical processes such as databases or message queues running on the EC2 instance by killing their underlying processes or threads. This fault determines the resilience of applications when processes on EC2 instances are unexpectedly killed (or disrupted).

Prerequisites

• Kubernetes > 1.16
• SSM agent is installed and running in the target EC2 instance.
• Create a Kubernetes secret that has the AWS Access Key ID and Secret Access Key credentials 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 = XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

• 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": [
        {
            "Effect": "Allow",
            "Action": [
                "ssm:GetDocument",
                "ssm:DescribeDocument",
                "ssm:GetParameter",
                "ssm:GetParameters",
                "ssm:SendCommand",
                "ssm:CancelCommand",
                "ssm:CreateDocument",
                "ssm:DeleteDocument",
                "ssm:GetCommandInvocation",          
                "ssm:UpdateInstanceInformation",
                "ssm:DescribeInstanceInformation"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2messages:AcknowledgeMessage",
                "ec2messages:DeleteMessage",
                "ec2messages:FailMessage",
                "ec2messages:GetEndpoint",
                "ec2messages:GetMessages",
                "ec2messages:SendReply"
            ],
            "Resource": "*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeInstanceStatus",
                "ec2:DescribeInstances"
            ],
            "Resource": [
                "*"
            ]
        }
    ]
}

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

Default validations

• The EC2 instance should be in healthy state
• The target processes should exist in the VM.

Fault tunables

Fault tunables

Mandatory fields

Variables	Description	Notes
EC2_INSTANCE_ID	ID of the target EC2 instance.	For example, i-044d3cb4b03b8af1f.
REGION	The AWS region ID where the EC2 instance has been created.	For example, us-east-1.
PROCESS_IDS	Process IDs of the target processes provided as comma-separated values.	For example, 183,253,857.

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.
RAMP_TIME	Period to wait before and after injecting chaos (in seconds).	For example, 30

Fault examples

Common fault tunables

Refer to the common attributes to tune the common tunables for all the faults.

Process IDs

It contains the target process IDs running on a particular EC2 instance.

You can tune it using the following example:

# Process kill running on EC2 instance
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: ec2-process-kill
    spec:
      components:
        env:
        # List of Process IDs
        - name: PROCESS_IDS
          value: '8688,4678'
        - name: EC2_INSTANCE_ID
          value: 'instance-1'
        - name: REGION
          value: 'us-west-2'