Activity Block Wrapper

Overview

This project includes a setup to wrap a user-defined block.py file into an activity block that runs within a managed worker environment. The setup uses entrypoint.py as a wrapper to dynamically load and execute the logic defined in block.py and make it available as an activity block. This README explains the purpose and functionality of entrypoint.py, the activity_block_wrapper base image, and how it all comes together within the Dockerfile to create a production-ready, deployable worker.

Files

1. entrypoint.py

entrypoint.py is the main entry script for the activity block wrapper. It provides the following functionality:

• Dynamic Loading: Imports block.py and retrieves its __main__ function dynamically. This function is wrapped and managed within the worker environment.
• Logging and Error Handling: Includes logging and error handling to ensure issues are properly recorded and managed, which is essential for production environments.
• Worker Management: Starts a worker instance that manages the execution of the activity block, making the block.py logic available as an activity in the specified task queue and namespace.

Configuration

• TASK_QUEUE: The task queue name for the worker. Set via environment variable.
• NAMESPACE: The namespace for the worker to operate within. Set via environment variable.

Example Usage

To configure and run entrypoint.py in your environment:

1. Set the TASK_QUEUE and NAMESPACE environment variables.
2. Run entrypoint.py, and it will automatically wrap block.py as an activity block within the worker.

2. Dockerfile

The Dockerfile is structured to create an image that:

• Uses activity_block_wrapper as a base, which includes entrypoint.py and pre-installed dependencies.
• Copies the user’s block.py and other project-specific files into the container.
• Creates a symbolic link to entrypoint.py as block.py, making it appear as if block.py is the entry point, while actually running entrypoint.py to manage the activity block.

Key Dockerfile Commands

• FROM activity_block_wrapper:latest: Builds on top of the activity_block_wrapper image, which includes the necessary runtime environment and entrypoint.py.
• COPY: Copies the user’s block.py and other related files into the container.
• RUN ln -s /app/entrypoint.py /app/block.py: Creates a symbolic link from entrypoint.py to block.py, allowing entrypoint.py to manage the activity block while maintaining block.py as the visible entry point.

Example Usage with Docker

1. Build the Base Image:

docker build -f Dockerfile.base -t activity_block_wrapper:latest .