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<@ULVA73B9P> How to authenticate the pull docker i...

# marvin-ai

An Vu Trong

03/19/2025, 7:06 AM

@Marvin How to authenticate the pull docker image for the workers to pull before each task?

Marvin

03/19/2025, 9:05 AM

To authenticate and pull a Docker image for workers to use in Prefect 3.x, you can utilize the

build_docker_image

function from the

prefect_docker.deployments.steps

module. Here's a concise guide: 1. Docker Credentials: Ensure you have Docker credentials ready. These can be passed as a dictionary to the

credentials

parameter in the

build_docker_image

function. 2. Build and Authenticate: Use the

build_docker_image

function to build the Docker image. You can pass your credentials for authentication, which allows the worker to pull the image securely. Here's a basic example of how you might set this up:

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python
from prefect_docker.deployments.steps import build_docker_image

# Example function to build a Docker image with authentication
def build_image_with_auth():
    credentials = {
        "username": "your_docker_username",
        "password": "your_docker_password"
    }
    
    result = build_docker_image(
        image_name="your_image_name",
        dockerfile="Dockerfile",
        credentials=credentials
    )

    return result

3. Worker Setup: Start a Prefect worker that will use this image. Ensure the worker is configured to pull images from Docker, which will use the credentials provided during the image build step. For more detailed information, refer to the Prefect documentation on Docker infrastructure. If you have further questions or need more specific guidance, feel free to ask.

An Vu Trong

03/19/2025, 9:06 AM

@Marvin How to design the deployment yaml that way?

Marvin

03/19/2025, 9:06 AM

To design a

prefect.yaml

file for deploying a flow with Docker image authentication, you can follow these steps: 1. Initialize Deployment Configuration: Use the Prefect CLI to initialize your deployment configuration, which will create a

prefect.yaml

file. You can do this with

prefect init

. 2. Docker Image Configuration: Utilize Prefect's Docker build step to specify your Docker image and authentication details. You can include fields for image name, tag, and credentials. 3. Templating: Use templated values in your

prefect.yaml

to avoid hardcoding sensitive information. This allows dynamic substitution of values at runtime. Here's a basic structure of what your

prefect.yaml

might look like:

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yaml
# prefect.yaml

deployments:
  - name: my-docker-deployment
    flow_name: my_flow
    infrastructure:
      type: docker-container
      image: "{{ build-image.image }}"
      image_pull_policy: "Always"
      job_variables:
        image_name: "your_image_name"
        tag: "latest"
        credentials:
          username: "{{ secrets.DOCKER_USERNAME }}"
          password: "{{ secrets.DOCKER_PASSWORD }}"
    tags: []
    schedule: {}

### Key Points: - Image and Tag: Use templated placeholders for the

image

field, like

{{ build-image.image }}

, which will be dynamically populated during the build step. - Credentials: Use Prefect's secret management to securely store and access Docker credentials. - Job Variables: Define

job_variables

to pass image details and credentials. For more detailed guidance, refer to the Prefect documentation on defining deployments with YAML. If you need further assistance or have specific use cases, feel free to ask.

An Vu Trong

03/19/2025, 9:06 AM

@Marvin Why not use Block ?

Marvin

03/19/2025, 9:07 AM

Using Prefect Blocks for Docker authentication provides a structured and secure way to manage configuration and credentials. Here's why you might consider using Blocks: 1. Secure Configuration Storage: Blocks allow you to securely store and manage credentials, such as Docker registry authentication details. This is especially useful for sensitive information that should not be hardcoded in deployment files. 2. Reusability: Blocks can be reused across multiple deployments and flows. Once you set up a Docker registry block with your credentials, it can be referenced in various parts of your Prefect workflows. 3. Typed Configuration: Blocks provide a schema for configuration, ensuring that all necessary fields are filled out correctly. This reduces errors and simplifies the management of configuration data. 4. Integration with Prefect UI: Blocks can be managed and inspected through the Prefect UI, providing a centralized way to handle configuration and secrets. 5. Ease of Use: By using blocks, you avoid the need to manually handle environment variables or additional YAML configurations for each deployment. For Docker authentication, you can create a block specifically for your Docker registry credentials. This block can then be referenced in your deployment YAML or flow scripts. For more details on how to use Prefect Blocks, you can refer to the Prefect Blocks documentation. If you have further questions or need more specific guidance on setting up a Docker registry block, feel free to ask.

An Vu Trong

03/19/2025, 9:52 AM

@Marvin How to automatically setup base template job when create workpool to make workpool auto remove docker container after the task is completed?

Marvin

03/19/2025, 9:52 AM

To automatically set up a base template job that ensures Docker containers are removed after task completion, you can configure the work pool's job template to include the

--rm

flag for Docker. This flag ensures that the container is automatically removed when it exits. ### Steps to Set Up: 1. Create a Work Pool: When creating a work pool, specify the Docker infrastructure type. This is typically done through the Prefect UI or CLI. 2. Configure Job Template: Modify the base job template for the work pool to include Docker options. You can use the

get_default_base_job_template_for_infrastructure_type

function from the

prefect.work_pool

module to fetch and customize this template. 3. Include
--rm
Option: Ensure that the job template includes the

--rm

flag in the Docker run command to automatically remove containers after they complete their task. Here's a conceptual example using the Prefect CLI or Python code:

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bash
prefect work-pool create my-docker-pool --type docker-container

Or in Python:

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python
from prefect.work_pool import create, get_default_base_job_template_for_infrastructure_type

# Create a Docker work pool
work_pool = create(name="my-docker-pool", type="docker-container")

# Fetch and customize the base job template
job_template = get_default_base_job_template_for_infrastructure_type("docker-container")
job_template['docker']['options'] = '--rm'

# Update the work pool with the customized template
work_pool.update(job_template=job_template)

### Key Points: - Docker Options: The

--rm

flag is crucial for auto-removal of containers. - Prefect CLI and API: Use these tools to create and manage work pools and job templates. For more detailed instructions, you can explore the Prefect infrastructure examples. If you need further assistance or have specific use cases, feel free to ask.

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