@Marvin When i use custom image for flows in Kubernetes setting, does prefect copy the flow source code into image? What is the path? How are imports handled?

When using a custom image for Prefect flows in a Kubernetes setting, Prefect does not automatically copy the flow source code into the image. Instead, you have to specify how and where the flow code is stored and retrieved. This is typically done using a source control system like Git. You can use the

from_source

method to specify the source of your flow code, such as a GitHub repository, and provide an entry point to the flow function. Here's a basic outline of how you might handle this: 1. Source Code Storage: Store your flow code in a Git repository or another git-based cloud storage solution. 2. Retrieving Code: Use the

from_source

method to specify the source location of your flow code at runtime. This method allows you to point to a repository and define the entry point for the flow. 3. Docker Image: If you want to bake the flow code into a Docker image, you can create a custom Dockerfile that includes your flow code and necessary dependencies. This requires manually adding your flow code to the image during the build process. 4. Handling Imports: Ensure all necessary packages are included in your Docker image, either through a

requirements.txt

file or by specifying them directly in the Dockerfile. For more details, you can refer to the Prefect documentation on storing flow code and the Kubernetes deployment example.

@Marvin suppose i use git as a source. My flow file, which i provide as entrypoint imports some classes from another file in git. Will Prefect copy both files to container? What would be the path to these files in the container?

When using a Git repository as the source for your Prefect flow, Prefect will clone the entire repository, not just the single file specified as the entry point. This means that all files in the repository, including those your flow file imports, will be available in the container. The path to these files in the container will be relative to the root of the cloned repository. Typically, the repository is cloned into the working directory of the container. Therefore, you can use relative imports in your flow file to access other files in the repository. For example, if your repository structure is as follows:

/repo
  /flows
    flow.py  # Your entrypoint
  /utils
    helper.py  # A module imported in flow.py

You can import

helper.py

in

flow.py

using a relative import like:

python
from utils import helper

For more details, you can refer to the Prefect documentation on storing flow code.