Chaos Toolkit Extension for Azure

This project is a collection of actions and probes, gathered as an extension to the Chaos Toolkit. It targets the Microsoft Azure platform.

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.

$ pip install -U chaostoolkit-azure

Usage

To use the probes and actions from this package, add the following to your experiment file:

{
    "type": "action",
    "name": "start-service-factory-chaos",
    "provider": {
        "type": "python",
        "module": "chaosazure.factory.actions",
        "func": "start_chaos",
        "secrets": ["azure"],
        "arguments": {
            "parameters": {
                "TimeToRunInSeconds": 45
            }
        }
    }
},
{
    "type": "action",
    "name": "stop-service-factory-chaos",
    "provider": {
        "type": "python",
        "module": "chaosazure.factory.actions",
        "func": "stop_chaos",
        "secrets": ["azure"]
    }
}

That's it!

Please explore the code to see existing probes and actions.

Configuration

Credentials

This extension uses the requests and Azure SDK libraries under the hood. The requests library expects that you have a PFX certificate, converted as to the PEM format, that allows you to authenticate with the Service Factory endpoint.

Generally speaking, there are two ways of doing this:

you have created a configuration file where you will run the experiment from (so with a ~/.sfctl/config file)

you explicitly pass the correct environment variables to the experiment definition as follows:

Configuration section:

{
    "endpoint": "https://XYZ.westus.cloudapp.azure.com:19080",
    "verify_tls": false,
    "use_ca": false
}

Secrets section:

{
    "azure": {
        "security": "pem",
        "pem_path": "./cluster-client-cert.pem"
    }
}

The PEM can also be passed as an environment variable:

{
    "azure": {
        "security": "pem",
        "pem_content": {
            "type": "env",
            "key": "AZURE_PEM"
        }
    }
}

The environment variable name can be anything.

The Azure SDK library on the other hand expects that you have set up a service principal and provide its credentials. With those credentials you are able to authenticate with the Azure infrastructure and to spread Chaos on e.g. virtual machines.

There are two ways of doing this:

you can either pass the name of the environment variables to the experiment definition as follows (recommended):

{
    "azure": {
        "client_id": "AZURE_CLIENT_ID",
        "client_secret": "AZURE_CLIENT_SECRET",
        "tenant_id": "AZURE_TENANT_ID"
    }
}

or you inject the secrets explicitly to the experiment definition:

{
    "azure": {
        "client_id": "your-super-secret-client-id",
        "client_secret": "your-even-more-super-secret-client-secret",
        "tenant_id": "your-tenant-id"
    }
}

Additionally you need to provide the Azure subscription id.

{
    "azure": {
        "subscription_id": "your-azure-subscription-id"
    }
}

Putting it all together

Here is a full example:

{
    "version": "1.0.0",
    "title": "...",
    "description": "...",
    "configuration": {
        "endpoint": "https://XYZ.westus.cloudapp.azure.com:19080",
        "verify_tls": false,
        "use_ca": false
    },
    "secrets": {
        "azure": {
            "security": "pem",
            "pem_path": "./cluster-client-cert.pem"
        }
    },
    "steady-state-hypothesis": {
        "title": "Services is healthy",
        "probes": [
            {
                "type": "probe",
                "name": "application-must-respond",
                "tolerance": 200,
                "provider": {
                    "type": "http",
                    "verify_tls": false,
                    "url": "https://some-url-in-cluster/"
                }
            }
        ]
    },
    "method": [
        {
            "type": "action",
            "name": "start-service-factory-chaos",
            "provider": {
                "type": "python",
                "module": "chaosazure.factory.actions",
                "func": "start_chaos",
                "secrets": ["azure"],
                "arguments": {
                    "parameters": {
                        "TimeToRunInSeconds": 45
                    }
                }
            },
            "pauses": {
                "after": 30
            }
        },
        {
            "type": "probe",
            "ref": "application-must-respond"
        },
        {
            "type": "action",
            "name": "stop-service-factory-chaos",
            "provider": {
                "type": "python",
                "module": "chaosazure.factory.actions",
                "func": "stop_chaos",
                "secrets": ["azure"]
            },
            "pauses": {
                "after": 5
            }
        },
        {
            "type": "probe",
            "name": "get-service-factory-chaos-report",
            "provider": {
                "type": "python",
                "module": "chaosazure.factory.probes",
                "func": "chaos_report",
                "secrets": ["azure"],
                "arguments": {
                    "start_time_utc": "1 minute ago",
                    "end_time_utc": "now"
                }
            }
        }
    ]
}

Contribute

If you wish to contribute more functions to this package, you are more than welcome to do so. Please, fork this project, make your changes following the usual PEP 8 code style, sprinkling with tests and submit a PR for review.

The Chaos Toolkit projects require all contributors must sign a Developer Certificate of Origin on each commit they would like to merge into the master branch of the repository. Please, make sure you can abide by the rules of the DCO before submitting a PR.

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:

$ python setup.py develop

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

tophatsteve/chaostoolkit-azure