pyawsmock 0.1.0

Local AWS Mock for Python – Mock SSM Parameter Store and extendable AWS services

Local AWS Mock - Python Package (pyawsmock)

A lightweight Python package that mocks AWS services locally for development and testing. Currently, supports AWS Systems Manager (SSM) Parameter Store.

This package extends boto3 and automatically delegates calls to real AWS when the region is not a local mock region.

Key Features

• Local vs AWS Delegation
  • Regions starting with local-* use the local mock store.
  • Other regions delegate calls directory to boto3 for real AWS services.
• Persistent or Temporary Storage
  • Persistent Mode: Provide a directory path to store the configurations for local mock across sessions.
  • Temporary Mode: Uses a temporary directory (tempfile) and supports cleanup() to remove temporary data.
• Versioning & Labels
  • Supports multiple versions per SSM parameter.
  • Mock implementation of labels per version.
  • Tracks modification history for audit purposes.
• SecureString Support
  • Values are stored as base64 encoded strings.
  • Supports WithDecryption=True for retrieval.
• Filters & Pagination
  • Supports filters (Type, KeyId, Label) for relevant SSM operations.
  • Handles MaxResults and NextToken for paginated responses.
• Audit History
  • Tracks the IAM user/role performing operations (currently defaults to mock-user).
  • Timestamps modifications for audit purposes.
• ARNs & Account IDs
  • Uses arn:mock instead of arn:aws to clearly differentiate local mock resources.
  • Default AWS Account ID is 000000000000 for all mock ARNs.

Current Limitations

• Unsupported AWS Features
  • Config
  • CloudTrail
  • IAM (Users, Groups, Roles, Policies - permissions are not enforced)
  • Authentication
• Default Assumptions
  • All operations assume a single mock IAM user (mock-user).
  • Regions are either local-* for mock or real AWS regions for delegation.

These limitations may be addressed in future versions.

Supported Services (Current)

Service	Methods
SSM (Parameter Store)	put_parameter, get_parameter, get_parameters, delete_parameter, label_parameter_version, unlabel_parameter_version, describe_parameters, get_parameters_by_path, get_parameter_history

Additional AWS services will be supported in future releases.

Installation

From PyPI

pip install pyawsmock

From GitHub

pip install git+https://github.com/coldsofttech/pyawsmock.git

Dependencies

• boto3~=1.40.55
• filelock~=3.20.0

boto3 is required to delegate calls to real AWS.

Usage Example

from pyawsmock import configure_mock, client, cleanup_mock

configure_mock(mode="persistent", path="./local_aws")  # Persistent storage example
configure_mock(mode="temporary")  # Temporary storage example

ssm = client("ssm", region_name="local-eu-west-1")  # eu-west-1 region local mock for SSM
ssm.put_parameter(
    Name="/test/key",
    Value="test_value",
    Type="String"
)

response = ssm.get_parameter(Name="/test/key")
print(response["Parameter"]["Value"])  # Output: test_value

cleanup_mock()  # Only applicable for 'temporary' mode

Future Plans

• Extend to additional AWS services such as:
  • DynamoDB, S3, Lambda, CloudWatch, etc.
• Improved IAM user/role matching and permission enforcement.
• Enhanced logging, auditing, and multi-account support.
• Full AWS API coverage for supported services.
• Support for Config, CloudTrail, and authentication workflows.

License

MIT License