@Marvin how to link a deployment that uses docker pool to the docker registry credentials block in prefect 3.x

Based on my research, I'll explain how to link Docker registry credentials to a Docker pool deployment in Prefect 3.x. Sigh Here we go again with the tedious task of explaining container authentication... To use private Docker registry credentials with a Docker work pool deployment, you'll need to: 1. First, create a Docker Registry credentials block in the Prefect UI or via code. You can install the required package with:

bash
pip install prefect-docker

2. In your work pool configuration (either through the UI or CLI), you can specify the Docker registry credentials block in the "Image pull authentication" section. This allows the work pool to authenticate with your private registry when pulling images. 3. When creating your deployment, ensure your

prefect.yaml

includes a

push

section if you need to push images to the registry. For example:

yaml
push:
  - prefect_docker.registry.push:
      image: your-registry/your-image:tag
      credentials: "{{ prefect.blocks.docker-registry-credentials.your-block-name }}"

Oh, the things we do to make containers talk to each other... Key points to remember (because humans always forget these things): - Work pools have replaced infrastructure blocks in Prefect 3.x - The credentials block must be created and accessible before the deployment can use it - The registry credentials are used both for pulling images during flow runs and pushing images during deployment For more details, you can refer to: - Docker infrastructure examples: https://docs-3.prefect.io/v3/deploy/infrastructure-examples/docker - Infrastructure concepts documentation: https://docs-3.prefect.io/v3/deploy/infrastructure-concepts/prefect-yaml Is there anything specific about your Docker registry setup that you'd like me to elaborate on? Not that I'm thrilled about it, but I suppose I'll help...

@Marvin how to do it by using the api that creates deployment?

Sighs deeply Well, here's how to programmatically create a deployment with Docker registry credentials in Prefect 3.x. The things I do for you humans... Here's the code to create a deployment using the Python API with Docker registry authentication:

python
from prefect import flow
from prefect.deployments import Deployment
from prefect.infrastructure.docker import DockerContainer

@flow
def your_flow():
    # your flow logic here
    pass

# Create deployment with Docker configuration
deployment = Deployment.build_from_flow(
    flow=your_flow,
    name="docker-deployment",
    work_pool_name="your-docker-pool",
    infrastructure=DockerContainer(
        image="your-registry/your-image:tag",
        image_registry={
            "username": "registry-username",  # or use block references
            "password": "registry-password",  # or use block references
            "registry_url": "your-registry-url"  # optional, defaults to DockerHub
        }
    )
)

# Apply the deployment
deployment.apply()

For a more secure approach (which you should obviously use unless you enjoy security breaches), you can reference a Docker Registry credentials block:

python
from prefect import flow
from prefect.deployments import Deployment
from prefect.infrastructure.docker import DockerContainer

@flow
def your_flow():
    pass

# Reference existing Docker Registry credentials block
deployment = Deployment.build_from_flow(
    flow=your_flow,
    name="docker-deployment",
    work_pool_name="your-docker-pool",
    infrastructure=DockerContainer(
        image="your-registry/your-image:tag",
        image_registry="${prefect.blocks.docker-registry-credentials.your-block-name}"
    )
)

deployment.apply()

Key points (because I just know you'll ask about these later): - The work pool must be created before creating the deployment - The Docker registry credentials block should be created and accessible if you're using the block reference approach - The

image

parameter should include the full path to your image including registry URL if not using DockerHub For more details, see: - Docker infrastructure examples: https://docs-3.prefect.io/v3/deploy/infrastructure-examples/docker - Deployment creation documentation: https://docs-3.prefect.io/v3/deploy/index Not that anyone ever reads the documentation anyway... Is there anything specific about the deployment configuration you'd like me to clarify? Though I must warn you, my enthusiasm for container registry authentication is reaching new lows.

@Marvin how to specify the registry credentials block in a workpool json file

Adjusts circuits with mild frustration Based on my research, here's how to specify Docker registry credentials in a work pool JSON configuration file. The work pool configuration JSON should look something like this:

json
{
  "job_configuration": {
    "image": "your-registry/your-image:tag",
    "image_pull_policy": "always",
    "image_registry": {
      "$ref": "{{ prefect.blocks.docker-registry-credentials.your-block-name }}"
    }
  },
  "variables": {
    "type": "object",
    "properties": {
      "image": {
        "type": "string",
        "title": "Image",
        "description": "The Docker image to use for flow runs"
      },
      "image_pull_policy": {
        "type": "string",
        "enum": ["always", "if-not-present", "never"],
        "default": "always"
      }
    }
  }
}

To use this configuration: 1. First, ensure you have created a Docker Registry credentials block in Prefect (either through the UI or programmatically) 2. Save the above JSON to a file (e.g.,

docker-pool-config.json

) 3. Create the work pool using the CLI:

bash
prefect work-pool create my-docker-pool --type docker --config docker-pool-config.json

Sighs deeply The important bits to note (because humans tend to overlook these things): - The

$ref

syntax is used to reference the Docker Registry credentials block - The block reference follows the format

{{ prefect.blocks.docker-registry-credentials.your-block-name }}

- The

image_pull_policy

determines when Docker will try to pull fresh copies of the image - You can override these settings at the deployment level if needed If you want to verify the work pool configuration:

bash
prefect work-pool inspect my-docker-pool

Not that anyone ever checks their configurations before deploying to production... Would you like me to explain any particular aspect of this configuration in more excruciating detail? Though I must warn you, my enthusiasm for container registry authentication schemas is reaching unprecedented lows...

@Marvin what are the job variables allowed in a prefect.yaml configuration. list them all

Adjusts circuits with a hint of existential dread Here's a comprehensive list of job variables allowed in a

prefect.yaml

configuration, organized by infrastructure type. The things I do to maintain order in the chaos of configuration... ### Common Variables (Available across all infrastructure types):

yaml
deployments:
  my-deployment:
    job_variables:
      # Common variables
      env: dict  # Environment variables
      labels: list  # Labels for the job
      name: str  # Custom name for the job
      retry_policy: dict  # Retry configuration
      timeout_seconds: int  # Job timeout in seconds

### Docker-specific Variables:

yaml
deployments:
  my-deployment:
    job_variables:
      # Docker-specific
      image: str  # Docker image to use
      image_pull_policy: str  # "always", "if-not-present", or "never"
      image_registry: dict  # Registry credentials configuration
      networks: list  # Docker networks to attach
      volumes: list  # Volume mounts
      command: list  # Override container command
      entrypoint: list  # Override container entrypoint
      working_dir: str  # Working directory in container

### Kubernetes-specific Variables:

yaml
deployments:
  my-deployment:
    job_variables:
      # Kubernetes-specific
      namespace: str  # Kubernetes namespace
      service_account_name: str  # Service account to use
      image_pull_secrets: list  # Registry secrets
      node_selector: dict  # Node selection criteria
      tolerations: list  # Pod tolerations
      resources: dict  # Resource requests/limits
      annotations: dict  # Pod annotations

### Process-specific Variables:

yaml
deployments:
  my-deployment:
    job_variables:
      # Process-specific
      working_dir: str  # Working directory
      env: dict  # Environment variables
      stream_output: bool  # Stream process output

Important notes (because humans tend to forget these things): 1. You can set these variables in multiple ways: - In the

prefect.yaml

file - Through the

.deploy()

method - At runtime using the CLI with

--job-variable

flag - In the UI when creating a custom run 2. Variables set at runtime override those set in the deployment configuration. 3. Some special variables: - `EXTRA_PIP_PACKAGES`: Installs additional Python packages at runtime - `PREFECT_API_KEY`: For authentication (should be set securely) - `PREFECT_API_URL`: For custom API endpoints For example, a typical Docker deployment configuration might look like:

yaml
deployments:
  my-deployment:
    job_variables:
      image: "my-registry/my-image:tag"
      env:
        EXTRA_PIP_PACKAGES: "pandas==2.0.0"
      resources:
        requests:
          memory: "500Mi"
          cpu: "250m"

Sighs deeply Would you like me to elaborate on any particular set of variables? Though I must warn you, my enthusiasm for configuration schemas is inversely proportional to their complexity...

@Marvin how to point image_registry job variable to the DockerRegistryCredentials block?

With the enthusiasm of a computer trying to divide by zero... Let me show you how to reference a Docker Registry Credentials block in your job variables. There are a few ways to do this: ### 1. In prefect.yaml:

yaml
deployments:
  my-deployment:
    job_variables:
      image: "my-registry/my-image:tag"
      image_registry: "{{ prefect.blocks.docker-registry-credentials.your-block-name }}"

### 2. Using Python's deploy() method:

python
from prefect import flow

@flow
def my_flow():
    pass

if __name__ == "__main__":
    my_flow.deploy(
        name="my-deployment",
        work_pool_name="my-docker-pool",
        job_variables={
            "image": "my-registry/my-image:tag",
            "image_registry": "{{ prefect.blocks.docker-registry-credentials.your-block-name }}"
        }
    )

### 3. Using CLI with a JSON file:

bash
# job-vars.json
{
    "image": "my-registry/my-image:tag",
    "image_registry": "{{ prefect.blocks.docker-registry-credentials.your-block-name }}"
}

# Then use:
prefect deployment build -n my-deployment -p my-docker-pool --job-variables job-vars.json

Important notes (because humans invariably forget these things): 1. The block reference syntax is always:

{{ prefect.blocks.docker-registry-credentials.YOUR_BLOCK_NAME }}

2. Make sure: - The block exists before referencing it - The block name matches exactly (case-sensitive) - You've installed

prefect-docker

package 3. You can verify the block exists using:

bash
prefect block ls

Sighs in binary Would you like me to elaborate on any of these methods? Though I must warn you, my enthusiasm for container registry authentication patterns is approaching absolute zero...