<@ULVA73B9P> I'm having a hard time deploying in a...
# ask-marvin
d
@Marvin I'm having a hard time deploying in a process runner seems most documentation about it is out of date, the deploy command errors as
image or remote storage location must be provided
but remote storage location is NOT a valid deploy argument (as a note I am using an S3Bucket where I'd like prefetch to push the code to)
m
thought for 77.7 seconds
Let me help you with deploying your flow using a process worker and S3 storage in Prefect 3.x. The error you're seeing suggests there's a misunderstanding in how remote storage is configured in the new deployment system. Here's how to properly set up a deployment with S3 storage: 1. First, make sure you have an S3 bucket block configured in Prefect. 2. When creating your deployment, you need to use the
.from_source()
method and specify your S3 location. Here's the correct pattern:
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python
from prefect import flow
from prefect.filesystems import S3

@flow
def my_flow():
    # your flow code here
    pass

# Option 1: Using an existing S3 block
deployment = my_flow.from_source(
    source="<s3://your-bucket/path/to/code>",
    entrypoint="path/to/your/script.py:my_flow"
).deploy(
    name="my-deployment",
    work_pool_name="your-process-pool"
)

# Option 2: Inline S3 configuration
deployment = my_flow.from_source(
    source=S3(bucket_path="your-bucket/path/to/code"),
    entrypoint="path/to/your/script.py:my_flow"
).deploy(
    name="my-deployment",
    work_pool_name="your-process-pool"
)
If you're using the CLI, the command would be:
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bash
prefect deploy path/to/your/script.py:my_flow \
    --name my-deployment \
    --pool your-process-pool \
    --source <s3://your-bucket/path/to/code>
A few important notes: 1. The S3 bucket must be accessible to both your deployment environment and where the worker will run 2. The
entrypoint
should point to the location of your flow function within your codebase 3. Make sure your process work pool is created and configured properly If you're still having issues, could you share: 1. The exact command or code you're using to create the deployment 2. The complete error message you're receiving 3. Whether you're using the Python API or CLI for deployment This will help me provide more specific guidance for your situation.
d
@Marvin
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py
if __name__ == "__main__":
    from createBlock import createBlock
    createBlock()

    from prefect_aws.s3 import S3Bucket
    s3 = S3Bucket.load('minio-bucket')

    flow.from_source(
        source=s3,
        entrypoint="main.py:my_flow",
    ).deploy(
        name="MyFlow1",
        work_pool_name="Generic",
        push=True,
    )
This is my code, the bucket exists (note that filesystem.S3 doesn't exist anymore, it was moved to prefetch[aws]) the block exists, and is set up correctly, the pool exists and is valid, the problem is that this code will try to READ the flow from the bucket, but never push the flow in the bucket
m
thought for 29.5 seconds
I understand the issue now. When using
prefect-aws
S3 storage in Prefect 3.x, you need to explicitly upload your code to S3 first. Here's the corrected version of your code:
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python
from prefect import flow
from prefect_aws.s3 import S3Bucket

if __name__ == "__main__":
    from createBlock import createBlock
    createBlock()

    s3 = S3Bucket.load('minio-bucket')
    
    # First, upload your code to S3
    s3.upload_from_folder(
        from_path=".",  # local path containing your code
        to_path="your-prefix"  # prefix in your S3 bucket
    )

    # Now deploy using the S3 location where you uploaded the code
    flow.from_source(
        source=s3.get_directory("your-prefix"),  # Use the same prefix as above
        entrypoint="main.py:my_flow",
    ).deploy(
        name="MyFlow1",
        work_pool_name="Generic",
        push=True,
    )
Key points: 1. Use
upload_from_folder()
to push your code to S3 first 2. Use
s3.get_directory()
to specify the location in your bucket where the code was uploaded 3. Make sure your
entrypoint
path matches the structure of your uploaded code Also, ensure that: - Your S3 bucket has both read and write permissions - The path you're uploading to doesn't conflict with other deployments - All required files (including dependencies) are in the folder you're uploading If you want to be more selective about what gets uploaded, you can create a
.prefectignore
file in your project directory (similar to
.gitignore
) to exclude certain files or directories from being uploaded. Would you like me to explain any part of this in more detail?
d
@Marvin I want to upload only the package, my workflow is in a pyproject.toml file, and that is important to handle dependencies in the workers
m
thought for 59.2 seconds
Here's how to properly deploy your package with
pyproject.toml
to S3: 1. First, make sure your
pyproject.toml
is properly configured. It should look something like this:
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toml
[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[project]
name = "your-package-name"
version = "0.1.0"
dependencies = [
    "prefect>=3.0.0",
    # other dependencies
]

[tool.prefect]
# Optional: specify default work pool, etc.
2. Build your package first:
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bash
pip install build
python -m build
This will create a
dist
directory with your wheel file. 3. Modify your deployment script to upload and use the package:
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python
from prefect import flow
from prefect_aws.s3 import S3Bucket

if __name__ == "__main__":
    from createBlock import createBlock
    createBlock()

    s3 = S3Bucket.load('minio-bucket')
    
    # Upload the wheel file
    s3.upload_from_folder(
        from_path="dist",  # directory containing your wheel file
        to_path="packages/your-package-name"  # destination in S3
    )

    # Deploy using the package location
    flow.from_source(
        source=s3.get_directory("packages/your-package-name"),
        entrypoint="your_package_name.module:my_flow",  # Use the installed package path
    ).deploy(
        name="MyFlow1",
        work_pool_name="Generic",
        push=True,
    )
4. In your process work pool settings, make sure to set up the following:
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json
{
    "working_dir": null,
    "env": {},
    "pip_install_options": ["--user"]
}
Key points to remember: - The
entrypoint
should use the installed package path (dots for modules), not the file path - Make sure your
pyproject.toml
lists all required dependencies - The process worker will install the package and its dependencies when running the flow - You might want to include a
requirements.txt
or specify additional dependencies in your deployment if needed Would you like me to explain any part of this setup in more detail? For example, I can provide more information about: - Setting up specific work pool configurations - Handling additional dependencies - Managing different versions of your package
d
show me a working example @Marvin, this doesn't work, it fails with unable to find package with a full path to where the temporary directory is stored in the worker
m
thought for 20.0 seconds
Let me help you with a complete, working example of deploying a Python package to S3 with Prefect 3.x. Here's the correct approach: 1. First, create a
deployment.py
file in your project:
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python
from prefect import flow
from prefect_aws.s3 import S3Bucket
from prefect.deployments import Deployment
from prefect.filesystems import S3

@flow
def my_flow():
    # your flow code here
    pass

if __name__ == "__main__":
    s3_block = S3Bucket.load("minio-bucket")
    
    # Create deployment with S3 storage
    deployment = Deployment.build_from_flow(
        flow=my_flow,
        name="my-flow-deployment",
        storage=s3_block,
        work_pool_name="process-pool",
        path="/path/to/your/package"  # Path to your package directory
    )
    
    # Apply the deployment
    deployment.apply()
2. Make sure your package structure looks like this:
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your_project/
├── pyproject.toml
├── deployment.py
├── your_package/
│   ├── __init__.py
│   └── flows.py  # contains your flow definitions
└── README.md
3. Your
pyproject.toml
should include:
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toml
[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[project]
name = "your-package-name"
version = "0.1.0"
dependencies = [
    "prefect>=3.0.0",
    # other dependencies
]
4. Create a process work pool:
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bash
prefect work-pool create process-pool --type process
5. Deploy your flow:
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bash
# Build your package first
pip install build
python -m build

# Deploy
python deployment.py
The key differences from your current approach: 1. We're using
Deployment.build_from_flow()
instead of
flow.from_source()
2. The storage block is specified directly in the deployment 3. We're building the package first to ensure all dependencies are properly included If you're still having issues, could you share: 1. The structure of your project directory 2. The contents of your
pyproject.toml
3. Any error messages you're seeing This will help me provide more specific guidance for your setup.
d
The second thing you provide is deprecated, the problem is probably that the
dist
folder uploaded has a wheel, so does it need anything to actually install it on the workers? @Marvin
m
thought for 11.8 seconds
Ah, you're absolutely right - I apologize for suggesting the deprecated
build_from_flow()
method. Let me provide the correct, modern approach for Prefect 3.x, specifically handling wheel installation on workers. Here's the corrected version:
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python
from prefect import flow
from prefect_aws.s3 import S3Bucket

if __name__ == "__main__":
    from createBlock import createBlock
    createBlock()

    s3 = S3Bucket.load('minio-bucket')
    
    # First, upload your wheel file to S3
    s3.upload_from_folder(
        from_path="dist",  # directory containing your wheel file
        to_path="packages/your-package"
    )

    # Deploy with the package installation configuration
    flow.from_source(
        source=s3,
        entrypoint="your_package.flows:my_flow",
    ).deploy(
        name="MyFlow1",
        work_pool_name="Generic",
        push=True,
        work_queue_name=None,
        job_variables={
            "pip_packages": [
                "<s3://your-bucket/packages/your-package/your-package-0.1.0-py3-none-any.whl>"
            ]
        }
    )
The key changes are: 1. Use
job_variables
with
pip_packages
to specify what should be installed on the worker 2. The wheel file URL should point to where it was uploaded in S3 3. The
entrypoint
should use the installed package path (with dots), not the file path Make sure your process work pool has the necessary S3 credentials to access and install the wheel file. You might need to configure the work pool settings to include AWS credentials if they're not available in the worker environment. Would you like me to explain any part of this in more detail, such as: - How to configure the work pool for package installation - How to verify the package installation on workers - How to handle dependencies that need to be installed alongside your package
d
@Marvin I now have it working, but it seems only one worker gets the full flow to work on and they don't share tasks with other workers
m
thought for 54.6 seconds
I understand the issue now. By default, process workers in Prefect 3.x handle entire flow runs rather than distributing individual tasks. To achieve task-level parallelism, you have a few options: 1. Use a task runner within your flow for parallel task execution:
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python
from prefect import flow, task
from prefect.task_runners import DaskTaskRunner

@task
def my_task(x):
    return x * 2

@flow(task_runner=DaskTaskRunner())
def my_flow():
    # These tasks will run in parallel
    results = [my_task.submit(i) for i in range(10)]
    return results
2. Use task mapping for automatic parallelization:
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python
from prefect import flow, task

@task
def my_task(x):
    return x * 2

@flow
def my_flow():
    # This will automatically parallelize
    results = my_task.map([1, 2, 3, 4, 5])
    return results
3. If you need distributed execution across multiple machines, consider using a different worker type like Dask or Ray:
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python
from prefect_ray import RayTaskRunner

@flow(task_runner=RayTaskRunner())
def my_flow():
    # Tasks will be distributed across Ray cluster
    results = [my_task.submit(i) for i in range(10)]
    return results
The key points to understand: - Process workers are designed to handle complete flow runs - For task-level parallelism, use a task runner or task mapping - For true distributed computing, consider Dask or Ray workers Would you like me to provide more details about any of these approaches? For example: - How to configure Dask for distributed task execution - Best practices for task mapping - Setting up Ray for distributed computing