Customize Python runtime environment

Build Custom Runtime Images

Zerops allows you to build custom runtime images (CRI) when the default base runtime images don't meet your Python application's requirements. This is an optional phase in the build and deploy pipeline.

Configuration

Default Python Runtime Environment

The default Python runtime environment contains:

• Alpine 3.20
• Selected version of Python when the runtime service was created
• zCLI
• Git and PIP

When You Need a Custom Runtime Image

If your Python application needs more than what's included in the default environment, you'll need to build a custom runtime image. Common scenarios include:

• System packages for processing: When your app processes images, videos, or files (requiring packages like sudo apk add --no-cache imagemagick)
• Python build tools: When you need setuptools, or other tools not included by default
• Scientific libraries: When you need NumPy, SciPy, or other packages requiring system dependencies
• Different base OS: When you need Ubuntu instead of Alpine for specific compatibility requirements

important

You should not include your application code in the custom runtime image, as your built/packaged code is deployed automatically into fresh containers.

Here are Python-specific examples of configuring custom runtime images in your zerops.yml:

Basic Python Setup

run:
  os: ubuntu
  base: python@3.12
  prepareCommands:
    - sudo apt-get update
    - sudo apt-get install -y some-package

Using Build Files in Runtime Preparation

build:
  addToRunPrepare:
    - requirements.txt
    - pyproject.toml
run:
  prepareCommands:
    - pip install -r requirements.txt

For complete configuration details, see the runtime prepare phase configuration guide.

Process and Caching

How Runtime Prepare Works

The runtime prepare process follows the same steps for all runtimes. See how runtime prepare works for the complete process details.

Caching Behavior

Zerops caches custom runtime images to optimize deployment times. Learn about custom runtime image caching including when images are cached and reused.

Build Management

For information about managing builds and deployments, see managing builds and deployments.

Warning

Shared storage mounts are not available during the runtime prepare phase.

Troubleshooting

If your prepareCommands fail, check the prepare runtime log for specific error messages.