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ECS container volume detach

ECS container volume detach provides a mechanism to detach and remove volumes associated with ECS task containers in an Amazon ECS (Elastic Container Service) task. This experiment primarily involves ECS Fargate and doesn't depend on EC2 instances. They focus on altering the state or resources of ECS containers without direct container interaction.

ECS Container Volume Detach

Use cases

ECS container volume detach:

  • Allows you to test and validate the behavior of your ECS tasks when volumes are detached. You can verify the resilience and performance of your application during volume detachment scenarios, ensuring that the containers continue to function as expected.
  • By detaching volumes, you can safely remove the volume associations from the containers without deleting the volumes themselves.
  • By detaching unnecessary volumes, you can optimize the resource utilization within your ECS tasks. This helps to free up storage space and minimize any potential performance impact associated with unused volumes.

Prerequisites

  • Kubernetes >= 1.17
  • ECS cluster running with the desired tasks and containers and familiarity with ECS service update and deployment concepts.
  • 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
tip

HCE recommends that you use the same secret name, that is, cloud-secret. Otherwise, you will need to update the AWS_SHARED_CREDENTIALS_FILE environment variable in the fault template with the new secret name and you won't be able to use the default health check probes.

Below is an example AWS policy to execute the fault.

{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"ecs:DescribeTasks",
"ecs:DescribeServices",
"ecs:DescribeTaskDefinition",
"ecs:RegisterTaskDefinition",
"ecs:UpdateService",
"ecs:ListTasks",
"ecs:DeregisterTaskDefinition"
],
"Resource": "*"
},
{
"Effect": "Allow",
"Action": [
"iam:PassRole"
],
"Resource": "*"
}
]
}
note

Mandatory tunables

Tunable Description Notes
CLUSTER_NAME Name of the target ECS cluster For example, cluster-1. For more information, go to cluster name.
SERVICE_NAME Name of the ECS service under chaos For example, nginx-svc. For more information, go to service name.
REGION Region name of the target ECS cluster For example, us-east-1.

Optional tunables

Tunable Description Notes
TOTAL_CHAOS_DURATION Duration that you specify, through which chaos is injected into the target resource (in seconds) Default: 30 s. For more information, go to duration of the chaos.
TASK_REPLICA_AFFECTED_PERC Percentage of total tasks that are targeted. Default: 100. For more information, go to ECS task replica affected percentage.
CHAOS_INTERVAL Interval between successive instance terminations (in seconds) Default: 30 s. For more information, go to chaos interval.
AWS_SHARED_CREDENTIALS_FILE Path to the AWS secret credentials Defaults to /tmp/cloud_config.yml.
RAMP_TIME Period to wait before and after injecting chaos (in seconds) For example, 30 s. For more information, go to ramp time.

ECS container volume detach

ECS container volume chaos will detach the volumes for specified chaos duration. Tune it by using the SERVICE_NAME and CLUSTER_NAME environment variable.

The following YAML snippet illustrates the use of this environment variable:

# Set container image for the target ECS task
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
name: aws-nginx
spec:
engineState: "active"
annotationCheck: "false"
chaosServiceAccount: litmus-admin
experiments:
- name: ecs-container-volume-detach
spec:
components:
env:
- name: CLUSTER_NAME
value: 'test-cluster'
- name: SERVICE_NAME
value: 'test-service'
- name: REGION
value: 'us-east-2'
- name: TOTAL_CHAOS_DURATION
VALUE: '60'

ECS task replica affected percentage

Number of tasks to target (in percentage). Tune it by using the TASK_REPLICA_AFFECTED_PERC environment variable.

The following YAML snippet illustrates the use of this environment variable:

# stop the tasks 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-task-stop
spec:
components:
env:
# provide the name of ECS cluster
- name: CLUSTER_NAME
value: 'demo'
- name: SERVICE_NAME
vale: 'test-svc'
- name: TASK_REPLICA_AFFECTED_PERC
vale: '100'
- name: REGION
value: 'us-east-1'
- name: TOTAL_CHAOS_DURATION
VALUE: '60'