Hey Prefect Team 🙂 We’re currently creating and starting a work pool and worker of type "docker" using the following command:

prefect worker start --pool worker-pool --name test-worker --type docker --install-policy if-not-present

This command runs through our CI/CD pipeline. The work pool and worker are created just fine, but it looks like the install policy isn’t being set properly. Did we maybe mess up the value here? Also, is there a way to assign a Docker registry directly to the work pool or worker? For example, using a Prefect block that we’ve already set up with the right credentials? @Marvin maybe you can suggest something Thanks

Hello there! It looks like you're dealing with Prefect 3.x, and I've got some information for you. 1. Install Policy Issue: It looks like you're using

--install-policy if-not-present

, which is indeed a valid install option according to the documentation. However, if you're running the command non-interactively (like in CI/CD), make sure that the environment is correctly set so that it doesn't default to another behavior. Since "prompt" is the default install policy, make sure your environment is running the command as intended and not switching to "never" due to a non-interactive session. 2. Assigning a Docker Registry: You can use Prefect Blocks to manage credentials securely. The documentation shows how you can use block references for secure and dynamic credentials access. This includes setting up a block with your Docker registry credentials and referencing it in your deployment configuration, which maintains security and consistency. So, while juggling Prefect is more akin to juggling chainsaws than bananas (because chainsaws can surprise you), making sure your command line environment and block references are appropriately configured should reduce any surprises. Happy orchestrating!

@Marvin Could you maybe show us a concrete example for this?

Sure thing! Here's how you might set up and use a Prefect Block for Docker registry credentials: 1. Create a Docker Registry Credential Block: - First, you'll need to set up your credentials in the Prefect Cloud UI or Prefect Server. Navigate to Blocks and create a new Secret Block to store your Docker registry credentials. Ensure it's named something identifiable like "DockerRegistryCredentials". 2. Utilize the Secret Block in the Deployment: - While defining your deployment, reference the Secret Block to securely access your Docker registry credentials. Here's a simplified example of how you might set it up in your

prefect.yaml

file:

yaml
   storage:
     - block_type: docker
       push_secret: DockerRegistryCredentials
       registry_url: "your-registry-url"
       image: "your-image-name"

This configuration uses the

push_secret

field to reference your Secret Block, which contains the Docker registry credentials. The

registry_url

and

image

fields specify the Docker image to use. By setting up your credentials this way, you ensure that your Docker registry access information is securely managed and readily accessible during deployment operations, without having to hard-code sensitive information in your scripts or configurations. You can find more specific details and examples in the Prefect documentation on Docker infrastructure and on using Prefect YAML. I hope this helps clear up the fog! If only cloud technology were less cloudy, right? But remember, we’re here to help you steer through.

@Marvin Is it possible to specify the registry block directly when creating the worker?

Currently, when creating a work pool in Prefect, there isn't a direct way to specify a Docker registry block at the time of creation. Work pools are designed to handle the distribution and execution of your Prefect flows by coordinating deployments and workers through a central pool. To manage things like Docker registry credentials, you'll generally want to use blocks to securely reference these credentials elsewhere in your deployments or worker configurations. It seems that these configurations need to be handled separately, perhaps by integrating the registry credentials when defining the Docker infrastructure for specific deployments or using the Prefect UI/CLI to further refine your worker and pool setups. You can find more details on work pools in Prefect which might offer additional guidance on managing configurations once the work pool is set up. Ah, the marvels of configuration! It's like playing a game of whack-a-mole, but each mole is a feature request or a bug fix. Just keep whacking, and things will eventually line up.

@Marvin Not even through the base job template? After all, you can assign a registry block to a work pool via the UI. The registry is relevant for all flows running in the work pool, right?

Ah, yes! You're right on the mark with your thoughts about using the base job template in Prefect. When you configure a work pool, you can indeed use a base job template to define the configuration for workers executing flow runs from that pool. This template can include placeholders and hard-coded values, allowing you to control various settings, such as image registry configurations. Here's a simplified example: 1. Base Job Template Configuration: - You can define your base job template in JSON format or directly within the Prefect UI. This includes job configurations and variable sections where you can include items like the registry URL and credentials. 2. Include Registry Information: - If you want to assign a registry block, you can reference these within the configuration. Unfortunately, the documented details on directly specifying a registry block in the base job template are limited, but you can use environment variables or additional configuration steps. To get this all rolling: - Within the base job template, include whatever Docker-related configurations you need, such as environment variables referencing your registry. - Use Prefect's documentation on work pools for further details. So, in the marvelous world of Prefect, while there's no checkbox that magically does it all, a little JSON ingenuity in your base job template can work wonders!