Integrating AWS CloudFormation template scanning into CI/CD pipelines is a perfect way to always catch security infringements before deployments occur. However, when the scanning tools used are external to the organization, such as Trend Micro's Cloud One Conformity (formerly Cloud Conformity), implementing and enforcing this in a multi team, multi account environment can present some challenges.

This solution allows for using the Cloud Conformity Template Scanner API in your AWS CodePipeline. AWS CodeBuild will fail if any submitted templates return failed checks, and results are presented using CodeBuild reports feature

NOTE: This repo accompanies an AWS DevOps blog entitled Enforcing AWS CloudFormation scanning in CI/CD Pipelines at scale using Trend Micro Cloud One Conformity. This is recommended reading to give in depth context to the solution provided in this repository

The wrapper API (called the Validate API in this solution, as it is used in pipelines to validate AWS CloudFormation templates) adds extra functionality when compared to the Cloud Conformity Template Scanner API directly:

1. Send multiple templates at once, within a single POST
2. Checks that the AWS account is currently being monitored by Cloud Conformity
   • If it is not being monitored, a VERY HIGH failing check is added to the test results
3. Returns the results in Cucumber JSON, a format supported by AWS CodeBuild reports.

Endpoints for viewing and manipulating the Accounts that the Authenticated User has permissions to access.

• Scan templates with Cloud Conformity : POST /validate/
• Request exception to a failing check : POST /exceptions/
• Approve an exception request : PUT /exceptions/
• Delete an exception : DELETE /exceptions/
• List exceptions : GET /exceptions/

The top half of the architecture diagram below depicts the main solution that this repository contains. The bottom half of the diagram depicts a typical usage scenario for a team's CI/CD pipeline to use the validate API.

An AWS CodeBuild project and AWS CodePipeline are also provided for an end-to-end example, and are discussed with full install instructions later in the readme. (see section Test using example CodePipeline)

This codebase will create a private API endpoint which can be used within your CI/CD pipeline AWS CodeBuild job to submit AWS CloudFormation templates to it. The API will then use the Cloud Conformity Template Scanner API to perform vulnerability scans upon the AWS Cloudformation templates. By using the API caller's AWS account number, you can be sure that the checks performed are exactly the same as the Cloud Conformity real time scanning running against the destination account.

Results from the API are returned in Cucumber JSON format, to enable easy viewing as part of CodeBuild test reports.

A suggested CodeBuild buildspec file is also included as part of this repository, to enable use within CodePipeline straight away.

The AWS account number of the calling account is required in the POST to the validate API (this is done automatically in the provided buildspec file). This is used to check against the list of accounts being monitored by Conformity in the organisation. If the account is not being monitored, this is treated as a very high failure (and should be rectified as soon as possible). See below for an example of this in action:

For ease of deployment, the architecture has been wrapped into an AWS SAM application.

• SAM CLI installed
• AWS CLI installed (with credentials set for the account to deploy to)
• CloudConformity account:
  • 30-day free trial of Cloud One (no credit card required)
  • Free tier of Cloud One – Conformity on the AWS Marketplace Cloud One listing

Update the samconfig.toml with account specific parameters:

Build and Deploy:

• First build the app:

  sam build --use-container
  

• Next, deploy the app:

  sam deploy -g

An API key from Cloud Conformity is required for the code to access the Template Scanner API. If you do not have one already, obtain one as follows:

Within the TrendMicro Cloud Conformity Console, log in with your user account and select User Settings. In the left navigation bar, select API Keys. At the top right of the API Keys screen, select +New API Key. Restrict the IP range if desired.

Once you have created the API Key, it displays in the Console under the Key ID with a status of Enabled.

The SAM application has created an AWS Secrets Manager entry to store the Conformity API key.

• Using the AWS Console, navigate to AWS Secrets Manager
• Open the secret at template-validator/<Stage> (where Stage was defined within the samconfig.toml file)
• Click Retrieve Secret Value then Edit
• Enter the Conformity API key as the value for api-key

The purpose of this API is that it can be called from CI/CD builds to validate cfn templates before they are deployed. A CodeBuild stage called "Validate" can be used to iterate over AWS CloudFormation templates, and fail the build if Cloud Conformity checks are failing.

More information on Test Reporting inside AWS CodeBuild is available here.

The buildspec file to be used is also contained within this repo:

• validate.buildspec.yml

This AWS CodeBuild project can then be used in AWS CodePipeline, as per the Validate stage in diagram below. The call to the Validate API remains internal to the AWS network, utilising the VPC Interface Endpoint for Amazon API Gateway (called execute-api) attached to the VPC that the validate project uses.

Whilst the above diagram shows a typical multi account and full CI/CD pipeline, for the purposes of testing a simpler environment is provided within this repository. This can be used to test the SAM validate-api deployment, and show how the CodeBuild validate stage can be used within CodePipeline.

The stack is defined in example-codepipeline.yaml.

This stack is an AWS CloudFormation stack and can be quickly launched through the Console.

As CodeBuild is running inside a VPC (to be able to access the private validate API), you will need to choose a VPC, Subnet and Security Group. The default VPC security group is suggested, as only outbound access is required. See "Notes on AWS CodeBuild inside VPC" section below for further information.

Alternatively, you can launch via the command line. For this method, you will need to provide the required VPC parameters via --parameter-overrides as per the command below:

aws cloudformation deploy \              
    --stack-name test-validate-pipeline \
    --template-file example-codepipeline.yaml \
    --capabilities CAPABILITY_NAMED_IAM \
    --parameter-overrides VpcId=<vpc-id> SubnetId=<subnet-id> SecurityGroupId=<security-group-id>

This stack will create aa AWS CodeCommit repository, and the CodePipeline will trigger on a commit to that repository. The repository is currently empty, so we need to add a file. The following command will add a CloudFormation template which defines an open S3 bucket. NOTE this stack and the S3 bucket within it will not get created in your account. It will only be picked up by CodePipeline and passed to the "Validate" CodeBuild stage, simulating your teams' CI/CD pipelines.

aws codecommit put-file --repository-name MyDemoRepo --branch-name main --file-content fileb://tests/payloads/openS3bucket.yaml --file-path build/openS3bucket.yaml --name "J Doe" --email "[email protected]" --commit-message "commit to trigger pipeline"

The CodePipeline can be viewed in the Console. After a short while the pipeline will start.

After a few minutes, the pipeline will fail. This is expected - the CodeBuild stage has picked up the public S3 bucket and sent to Cloud Conformity for scanning. Cloud Conformity will have alerted that there are VERY HIGH security risks with defining a public S3 bucket.

The full report can be viewed through the Console:

• Navigate to CodePipeline "ExampleCodePipelineWithTemplateValidationPhase"
• Click on details on CodeBuild stage
• Click Reports tab
• Click on the report in the Report History tab

You can now see all the Cloud Conformity errors relating to the template which was committed to the repository.

In real life, this template can be the output of another Build CodeBuild stage, or another location within your repository.

When configuring CodeBuild, to ensure it can access the private API gateway, it needs to be VPC attached. When choosing a subnet to place CodeBuild within, ensure that the private subnet has internet access via NAT gateway OR the following VPC endpoints are configured:

To remove all resources created by this repository, and to ensure no ongoing charges are billed to your account, perform the following steps.

In the AWS console:

• Navigate to the AWS CloudFormation service
• Delete the stack called test-validate-pipeline
• Delete the stack for the SAM application (name was provoded during the sam deploy command earlier)
• (optional) If you created any VPC endpoints for the example pipeline, navigate to the VPC service and delete them.

For more information on Trend Micro / Cloud Conformity, use the links below.

• Try for free: 30-day free trial of Cloud One (no credit card required) or via the free Cloud One – Conformity tier on the AWS Marketplace Cloud One listing
• Overview of Cloud One - Conformity
• Conformity’s Template Scanner Documentation
• Conformity’s Template Scanner API reference

This repository is provided as a working base for you to use within your own projects. If you have enhancements or bug fixes that will benefit future users of this code, please do raise an issue, or preferably a pull request.

Tests are defined in the tests folder in this project. Use pip to install the test dependencies and run tests.

Test can be executed by:

# install both prod and dev packages
pip install -r requirements-dev.txt --user
pip install -r src/requirements.txt --user

# install the package in 'editable' mode
pip install -e . --user

# run tests
python -m pytest tests/unit -v