potemkin-decorator 0.0.13
Decorator to help for AWS/boto integration testing in pytest
License: MIT
Requires Python: >=3.6

The potemkin decorator facilitates "integration testing" boto code by creating AWS resources 
using Cloudformation or Terraform. This provides a convenient way to setup initial conditions
instead of having to develop boto code that is likely as complex as the "code under test".

## Basic Usage

### CloudFormation

Here is an example CloudFormation invocation from pytest:
```
import potemkin
import boto3


@potemkin.CloudFormationStack(
  'test/integration/test_templates/aes256_bucket.yml',
  stack_name_stem='TestStack',
  parameters={'BucketName': 'unclefreddie33388'},
  aws_profile='myprofile',
  teardown=False
)
def test_bucket_has_aes256_encryption(stack_outputs, stack_name):
  full_bucket_name = stack_outputs['BucketNameOut']

  s3 = boto3.Session(profile_name='myprofile').client('s3')
  get_bucket_encryption_response = s3.get_bucket_encryption(
    Bucket=full_bucket_name
  )

  assert get_bucket_encryption_response['ServerSideEncryptionConfiguration']['Rules'][0]['ApplyServerSideEncryptionByDefault']['SSEAlgorithm'] == 'AES256'
``` 

The CloudFormationStack creates the stack and binds the outputs to stack_outputs.  The pytest method
could invoke more boto code to manipulate the resources created by the decorator.  In this case,
the test just asserts that the initial condition is what is expected.

This is basically a python/pytest port of "aws-int-test-rspec-helper" that worked with Ruby/RSpec:
* https://github.com/stelligent/aws-int-test-rspec-helper/

### Terraform
Here is an example Terraform invocation from pytest:
```
import potemkin
import boto3


@potemkin.TerraformResources(
  'test/integration/test_templates/terraform',
  parameters={'BucketName': 'unclefreddie33388'},
  aws_profile='myprofile',
  teardown=False
)
def test_bucket_has_aes256_encryption(tf_outputs):
  full_bucket_name = tf_outputs['BucketNameOut']

  s3 = boto3.Session(profile_name='myprofile').client('s3')
  get_bucket_encryption_response = s3.get_bucket_encryption(
    Bucket=full_bucket_name
  )

  assert get_bucket_encryption_response['ServerSideEncryptionConfiguration']['Rules'][0]['ApplyServerSideEncryptionByDefault']['SSEAlgorithm'] == 'AES256'
``` 

TerraformResources creates the resources and binds the outputs to tf_outputs.  The pytest method
could invoke more boto code to manipulate the resources created by the decorator.  In this case,
the test just asserts that the initial condition is what is expected.


## Service Specific Usage

The potemkin decorator has additional functions for interacting with specific AWS services 

### AWS Config
AWS Config initiates evaluations when a resource is created, but the evaluations are completed
asynchronously. They can take several minutes to complete. The AWS config functions wait until 
the config rule has an evaluation for the resource, then returns the evaluation.

### config_rule_wait_for_compliance_results
This function polls aws config until all resource_ids have evaluations. It then checks those evaluations
against expected results and returns a truthy value. This can be used by both configuration
change events and periodic events (by setting evaluate=True)


```
@potemkin.CloudFormationStack('test/integration/test_templates/eip.yml',
                              stack_name_stem='EipTestStack')
def test_wait_for_compliance_results(stack_outputs, stack_name):
    global expected_results
    configservice = boto3.Session().client('config')

    expected_results_success = {
        stack_outputs['EIPOutput']: "NON_COMPLIANT",
        stack_outputs['EIP2Output']: "NON_COMPLIANT"
    }

    assert config_rule_wait_for_compliance_results(
        configservice,
        rule_name='eip-attached',
        expected_results=expected_results_success)
```

### config_rule_wait_for_absent_resources
This function is a companion to config_rule_wait_for_compliance_results and is used to validate that
once resources are deleted they are removed from AWS config. 

```
def test_wait_for_compliance_results_success_results():
    configservice = boto3.Session().client('config')
    resource_ids = list(expected_results.keys())

    assert [] == config_rule_wait_for_absent_resources(
        configservice, rule_name='eip-attached', resource_ids=resource_ids)
```

#### config_rule_wait_for_resource
This function polls aws config until there is an evaluation for the resource, then returns it. Use this 
function for config rules with a configuration change trigger. If you are checking more than one 
resource, consider using config_rule_wait_for_compliance_results.

```
import potemkin
import boto3


@potemkin.CloudFormationStack(
  'test/integration/test_templates/aes256_bucket.yml',
  stack_name_stem='TestStack',
  parameters={'BucketName': 'unclefreddie33388'}
)
def test_bucket_encryption_rule(stack_outputs, stack_name):
  configservice = boto3.Session().client('config')

  results = config_rule_wait_for_resource(configservice, 
                                          resource_id='unclefreddie33388', 
                                          rule_name='config-rule-s3-encryption')

  assert results['ComplianceType'] == 'NON_COMPLIANT'
``` 


#### evaluate_config_rule_and_wait_for_resource
This is similar to config_rule_wait_for_resource but it first initiates a config evaluation. Use this 
for config rules with a periodic trigger. If you are checking more than one 
resource, consider using config_rule_wait_for_compliance_results.

```
import potemkin
import boto3


@potemkin.CloudFormationStack(
  'test/integration/test_templates/aes256_bucket.yml',
  stack_name_stem='TestStack',
  parameters={'BucketName': 'unclefreddie33388'}
)
def test_bucket_encryption_rule(stack_outputs, stack_name):
  configservice = boto3.Session().client('config')

  results = evaluate_config_rule_and_wait_for_resource(configservice, 
                                                      resource_id='unclefreddie33388', 
                                                      rule_name='config-rule-s3-encryption')

  assert results['ComplianceType'] == 'NON_COMPLIANT'
```