Registry / aws / cloudformation-cli

cloudformation-cli

library0.2.39pypypiunverified

CloudFormation CLI (cfn-cli) is the official AWS tool for building, testing, and publishing AWS CloudFormation resource type providers, modules, and hooks. The current version is 0.2.39. It allows developers to create custom CloudFormation resource types using Java or Python, run contract tests, and submit them to the CloudFormation registry. The release cadence is irregular, with 3-4 minor releases per year.

aws devops

pip install cloudformation-cli

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · CLOUDFORMATION-CLI

cloudformation-cli

awspythonv0.2.39

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

BaseResourceHandler

✓ from rpdk import BaseResourceHandler

✗ from cloudformation_cli_python_lib import BaseResourceHandler, exceptions

exceptions

✓ from rpdk import exceptions

✗ from cloudformation_cli_python_lib import BaseResourceHandler, exceptions

Initialize a CloudFormation resource type project and implement a basic resource handler using the Python library.

import os import json # Initialize a new resource type project os.system('cfn init') # Example: simple resource handler (Java in README, Python equivalent) # Usually generated; here's a minimal Python handler placeholder from cloudformation_cli_python_lib import BaseResourceHandler, exceptions class MyResource(BaseResourceHandler): def create(self, request): # model = request.desiredResourceState # ... implement create logic return {"resourceModel": request.desiredResourceState} def read(self, request): pass def update(self, request): pass def delete(self, request): pass # To run contract tests: # os.system('cfn test')

cfn --version

Debug

Known issues

gotchaWhen running `cfn test`, ensure Docker is installed and the daemon is running, as contract tests spin up a local Lambda-like container.

fix

Install Docker Desktop and start the daemon before running `cfn test`.

affects: all

gotchaThe `cfn submit` command requires valid AWS credentials with permissions to register resource types. Many users fail to configure credentials, leading to `AccessDenied` errors.

fix

Run `aws configure` or set environment variables AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_DEFAULT_REGION.

affects: all

breakingIn v0.2.30+, the `cfn generate` command requires the CloudFormation resource schema to be present; omitted schema leads to `FileNotFoundError`.

fix

Ensure you are in the project root with a valid `resource-role.yaml` or schema file before running `cfn generate`.

affects: >=0.2.30

deprecatedPython 3.6 support ended with v0.2.33; the latest versions require Python >=3.7.

fix

Upgrade to Python 3.7 or later (recommend 3.9+).

affects: >=0.2.33

Upgrade

Version history

0.2.39latest on PyPI · released Mar 31, 2025

Audit

Dependencies

awsclioptionalRequired for credential management and AWS API calls if not using boto3 directly.

dockeroptionalRequired for contract tests that run lambda-like environments.

Agent activity

25 hits · last 30 days

node

Amazon

Resources

githubhttps://github.com/aws-cloudformation/aws-cloudformation-rpdk ↗

packagehttps://pypi.org/project/cloudformation-cli/ ↗

homepagehttps://docs.aws.amazon.com/cloudformation-cli/latest/userguide/what-is-cloudformation-cli.html ↗