aws-az-failure-chaostoolkit 0.1.0

Custom Chaos Toolkit extension to simulate AZ failure on AWS resources

Chaos Toolkit AZ Failure Extension for AWS

This project is a collection of actions, gathered as an extension to the Chaos Toolkit to test the resiliency of your applications hosted on AWS.

Install

This package requires Python 3.5+

To be used from your experiment, this package must be installed in the Python environment where chaostoolkit already lives.

Install via pip

$ pip install -U aws-az-failure-chaostoolkit

Usage

To use the probes and actions from this package, add the following to your experiment file (replace Key1 and Value1 to the appropriate key-value pair you tagged your resources with):

This action removes subnets belonging to the target AZ in all tagged ASGs and suspends AZRebalance process if its running, or updates the min, max and desired capacity to 0 for the ASG if it's only configured for one AZ:

- type: action
  name: Simulate AZ Failure for ASG
  provider:
    type: python
    module: azchaosaws.asg.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      tags:
        - Key: "Key1"
          Value: "Value1"

This action with network failure will affect tagged/filtered subnets in the target AZ by replacing the current NACL association with a newly created blackhole NACL:

- type: action
  name: Simulate AZ Failure for EC2
  provider:
    type: python
    module: azchaosaws.ec2.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      failure_type: "network"
      filters:
        - Name: tag:TagKey1
          Values:
            - "TagValue1"

This action with instance failure will affect tagged/filtered instances in the target AZ that are in pending/running state by stopping/terminating normal/spot instances:

- type: action
  name: Simulate AZ Failure for EC2
  provider:
    type: python
    module: azchaosaws.ec2.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      failure_type: "instance"
      filters:
        - Name: tag:TagKey1
          Values:
            - "TagValue1"

This action removes subnets from target AZ in tagged application load balancers:

- type: action
  name: Simulate AZ Failure for ALB
  provider:
    type: python
    module: azchaosaws.elbv2.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      tags:
        - Key: "Key1"
          Value: "Value1"

This action detaches classic load balancers from subnets belonging to target AZ if they are in non-default VPC, and disables target AZ from classic load balancer if they are in a default VPC:

- type: action
  name: Simulate AZ Failure for CLB
  provider:
    type: python
    module: azchaosaws.elb.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      tags:
        - Key: "Key1"
          Value: "Value1"

This action forces RDS to reboot and failver to another AZ:

- type: action
  name: Simulate AZ Failure for RDS
  provider:
    type: python
    module: azchaosaws.rds.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      tags:
        - Key: "Key1"
          Value: "Value1"

This action forces ElastiCache (cluster mode disabled) to failover primary nodes if exists in the target az:

- type: action
  name: Simulate AZ Failure for ElastiCache (cluster mode disabled)
  provider:
    type: python
    module: azchaosaws.elasticache.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      tags:
        - Key: "Key1"
          Value: "Value1"

This action forces ElastiCache (cluster mode enabled) to failover the shards provided as cache cluster ids (sequential if multiple shards of same cluster) (replace ReplicationGroup1, CacheClusterId1 and CacheClusterId2 if needed):

- type: action
  name: Simulate AZ Failure for ElastiCache (cluster mode enabled)
  provider:
    type: python
    module: azchaosaws.elasticache.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      tags:
        - Key: "Key1"
          Value: "Value1"
      replication_groups:
        - replication_group_id: ReplicationGroup1
          cache_cluster_ids:
            - CacheClusterId1
            - CacheClusterId2

This action removes subnets belonging to the target AZ in all nodegroup ASGs that are part of the tagged EKS clusters and suspends AZRebalance process if its running. Network failure will affect subnets of the nodegroups in the target AZ by associating a newly created blackhole NACL. All its previous NACL association will be replaced with the blackhole NACL:

- type: action
  name: Simulate AZ Failure for EKS Clusters
  provider:
    type: python
    module: azchaosaws.eks.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      failure_type: "network"
      tags:
        - Key1: "Value1"

This action removes subnets belonging to the target AZ in all nodegroup ASGs that are part of the tagged EKS clusters and suspends AZRebalance process if its running. Instance failure will affect instances part of the node groups that are in the target AZ that are in pending/running state by stopping normal/spot instances:

- type: action
  name: Simulate AZ Failure for EKS Clusters
  provider:
    type: python
    module: azchaosaws.eks.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      failure_type: "instance"
      tags:
        - Key1: "Value1"

This action reboots the specified brokers that are tagged, or tagged brokers if broker_ids not specified:

- type: action
  name: Simulate AZ Failure for Amazon MQ (ActiveMQ)
  provider:
    type: python
    module: azchaosaws.mq.actions
    func: fail_az
    arguments:
      az: "ap-southeast-1a"
      tags:
        - "Key1": "Value1"
      broker_ids: 
        - BrokerId1
        - BrokerId2

To 'rollback' the changes made by the fail_az action, you can use recover_az in your experiment template. The recover_az function will read the state file generated and rollback if it's a service that's supported.

Please explore the code to see existing probes, actions and supported capabilities.

Alternatively, you can run chaos discover aws-az-failure-chaostoolkit to view the list of supported actions and probes along with their required and optional arguments for each service in the generated discovery.json file.

Do also note that by default, the dry_run argument for the functions are set to True. Set it to False if you want the actions to make changes your resources.

Configuration

Develop

If you wish to develop on this project, make sure to install the development dependencies. But first, create a virtual environment and then install those dependencies.

$ pip install -r requirements-dev.txt -r requirements.txt

Then, point your environment to this directory:

$ pip install -e .

Now, you can edit the files and they will be automatically be seen by your environment, even when running from the chaos command locally.

Test

To run the tests for the project execute the following:

$ pytest

Security

See CONTRIBUTING for more information.

License

This project is licensed under the Apache-2.0 License.