<@ULVA73B9P> I would like to use the process worke...
# ask-marvin
t
@Marvin I would like to use the process worker and deploy flows from my local GitLab. I want to install the flow’s dependencies in a separate virtual environment (venv) so that I don’t compromise the system Python of the process worker’s host. What do I need to consider in this context, and how can I configure this in the Prefect deployment YAML file?
m
thought for 92.2 seconds
Based on my research, I can provide a comprehensive answer about setting up a process worker with virtual environments for GitLab-based deployments. Here's what you need to know: 1. Work Pool Setup First, you'll need to create a process-type work pool:
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prefect work-pool create "my-process-pool" --type process
2. Deployment Configuration Create a deployment YAML file (e.g.,
deployment.yaml
) with the following structure:
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yaml
deployments:
  - name: my-flow-deployment
    version: null
    tags: []
    description: null
    schedule: {}
    flow_name: my_flow
    entrypoint: path/to/flow.py:my_flow
    parameters: {}
    work_pool:
      name: my-process-pool
      work_queue_name: default
    source:
      type: gitlab
      repository: <https://gitlab.com/your-username/your-repo>
      branch: main
      path: path/to/flow.py
    job_variables:
      env:
        PREFECT_PYTHON_PATH: "/path/to/your/venv/bin/python"
      working_dir: "/path/to/working/directory"
3. Virtual Environment Setup You have two main approaches: a) Pre-created Virtual Environment: - Create the virtual environment beforehand on the worker machine:
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   python -m venv /path/to/your/venv
   /path/to/your/venv/bin/pip install -r requirements.txt
- Specify this environment in the deployment configuration using
PREFECT_PYTHON_PATH
b) Dynamic Virtual Environment: - You can create a wrapper script that creates and activates a virtual environment before running the flow - Add this as a
before_script
in your deployment configuration 4. Important Considerations: - The process worker needs access to: - The GitLab repository (proper credentials/access tokens if private) - Permission to create/access virtual environments in the specified location - Python and virtualenv installed on the system - Sufficient disk space for virtual environments 5. Running the Worker Start the process worker:
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prefect worker start -p "my-process-pool"
6. Deploy Your Flow Deploy using:
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prefect deploy --name my-flow-deployment
Best Practices and Tips: 1. Environment Management: - Consider using a requirements.txt or setup.py in your GitLab repository - Use specific version numbers for dependencies to ensure reproducibility - Consider cleaning up old virtual environments periodically 2. Security Considerations: - Ensure the process worker has minimal necessary permissions - Store sensitive credentials in Prefect blocks rather than in code - Use GitLab deploy tokens or SSH keys for repository access 3. Monitoring: - Monitor disk usage as virtual environments can take up significant space - Keep track of virtual environment creation/deletion logs - Use Prefect's logging capabilities to track environment setup issues Limitations: - The process worker executes flows on the same machine where it runs, so ensure adequate resources - You'll need to manage virtual environment cleanup manually - Each flow run might require its own virtual environment, which could impact disk space Would you like me to elaborate on any of these aspects or provide more specific details about any part of the configuration?