<@ULVA73B9P> i keep getting this error or regular ...
# ask-marvin
v
@Marvin i keep getting this error or regular basis fatal: unable to access 'https://github.com/glsauto/prefect.git/ when ever i try to run my orchestration tool .As a fix i need to retry the flow manually and how do i fix this automated way. I am in prefect 2.0
m
To automate retries for your flow when encountering issues like "fatal: unable to access," you can utilize Prefect's built-in retry functionality for tasks. This can be particularly useful for handling network-related errors that might resolve themselves after a short delay. ### Steps to Implement Automatic Retries in Prefect 2.x 1. Define Retries for Tasks: You can specify retries and retry delays directly on tasks within your flow. This is useful if the failure occurs during a specific task execution.
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python
    from prefect import task, flow

    @task(retries=3, retry_delay_seconds=10)
    def clone_repository():
        # Code to clone repository
        pass

    @flow
    def my_flow():
        clone_repository()

    if __name__ == "__main__":
        my_flow()
2. Handling Flow-Level Retries: If the issue is at the flow level, Prefect allows you to specify retries for the entire flow as well.
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python
    from prefect import flow

    @flow(retries=3, retry_delay_seconds=10)
    def my_flow():
        # Code for the flow
        pass

    if __name__ == "__main__":
        my_flow()
3. Error Handling: Consider adding error handling logic to capture specific exceptions and trigger retries conditionally. ### Additional Considerations - Network Stability: Ensure your network connection is stable, as intermittent issues can cause these failures. - GitHub Access: Verify that your GitHub credentials and access tokens are correctly configured. Issues with credentials can lead to access errors. For more details on retries in Prefect, you can refer to Prefect's documentation on retries. If you encounter persistent issues, you might also want to explore related GitHub issues for community insights or report new bugs if necessary. Related GitHub Issues: - Retry Cloning Of Remote Repository Upon Failure - Github Credentials for Private Repo not usable with Prefect Projects These issues may offer additional context or workarounds for similar problems.
v
@Marvin my deployment code is something like this , here i am unable to retrieve the code only . and how do i add retries to this
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import sys, os
sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), '../../../Prefect')))
from prefect.deployments import Deployment
from prefectconfig import get_default_settings
from flows.flowname import test_flow


github_block, azure_container_instance_job_block, work_pool_name, work_queue_name = get_default_settings()
deployment = Deployment.build_from_flow(
    flow = test_flow,
    name = "test-flow",
    work_pool_name = work_pool_name,
    work_queue_name = work_queue_name,
    tags = ["tag1"],
    storage = github_block,
    infrastructure = azure_container_instance_job_block
)
if __name__ == "__main__":
    deployment.apply()
m
To add retries to your deployment process in Prefect 2.x, you can focus on the task level within your flow rather than directly on the deployment itself. Here's how you can incorporate retries: ### Adding Retries to Tasks 1. Define Retries for Specific Tasks: You can specify retries for tasks that might fail due to transient issues, such as network errors when accessing GitHub.
Copy code
python
    from prefect import task, flow

    @task(retries=3, retry_delay_seconds=10)
    def clone_repository():
        # Code to clone repository
        pass

    @flow
    def test_flow():
        clone_repository()
        # Other tasks

    if __name__ == "__main__":
        test_flow()
### Deployment Code Your deployment code is primarily responsible for setting up the flow execution environment. However, retries are typically handled within the flow's tasks:
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python
import sys, os
from prefect.deployments import Deployment
from prefectconfig import get_default_settings
from flows.flowname import test_flow

sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), '../../../Prefect')))

github_block, azure_container_instance_job_block, work_pool_name, work_queue_name = get_default_settings()

deployment = Deployment.build_from_flow(
    flow=test_flow,
    name="test-flow",
    work_pool_name=work_pool_name,
    work_queue_name=work_queue_name,
    tags=["tag1"],
    storage=github_block,
    infrastructure=azure_container_instance_job_block
)

if __name__ == "__main__":
    deployment.apply()
### Additional Considerations - Error Handling: Ensure that your tasks include error handling logic to manage specific exceptions gracefully. - Configuration: Double-check that your GitHub credentials and access tokens are correctly configured to avoid access issues. For more details on deploying flows and managing retries, refer to Prefect's deployment documentation. If you encounter issues with retrieving the flow code, ensure that the
github_block
is correctly set up to point to the right repository and branch.
v
@Marvin Flow level retry may not work as the deployment code failed to fetch the code at first place.
m
In Prefect 2.x, if your deployment fails to fetch the code from a remote repository, you should focus on configuring retries at the level of the code retrieval process itself. This typically involves ensuring that the
github_block
or any storage block you are using is correctly configured to handle transient failures. ### Steps to Implement Code Retrieval Retries 1. Verify GitHub Block Configuration: Ensure that your
github_block
is properly set up with the correct repository URL and access credentials. This is crucial for successful code retrieval. 2. Custom Code Retrieval Logic: If Prefect's built-in mechanisms don't support retries at the deployment level, consider implementing a custom wrapper around the code retrieval logic to handle retries. This can be done using Python's retry libraries or custom logic. 3. Use Git Clone with Retries: If you are using a custom storage block or manual code retrieval, you can implement retries using a loop with error handling:
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python
    import time
    import subprocess

    def clone_with_retries(repo_url, retries=3, delay=10):
        for attempt in range(retries):
            try:
                subprocess.run(["git", "clone", repo_url], check=True)
                break  # Exit loop if successful
            except subprocess.CalledProcessError:
                if attempt < retries - 1:
                    time.sleep(delay)
                else:
                    raise

    # Example usage
    clone_with_retries("<https://github.com/your-repo.git>")
4. Prefect's Custom Steps: Consider using Prefect's custom steps to manage the code retrieval process with retries. You can explore the
prefect.deployments.steps.pull
module to implement or modify the
git_clone
function with retry logic. ### Additional Considerations - Network Stability: Ensure your network is stable and not causing intermittent failures. - Access Tokens: Double-check that your GitHub access tokens are valid and have the necessary permissions. By implementing retries at the code retrieval level, you can mitigate issues that occur before the flow execution begins. If you need more tailored solutions, consider exploring Prefect's GitHub issues for community discussions and potential workarounds.
v
@Marvin what does this code GitHub.load means
m
The
GitHub.load
method is typically associated with loading a configuration or storage block related to GitHub in Prefect. In the context of Prefect, storage blocks are used to define where and how flow code is stored and retrieved. ### Usage of
GitHub.load
- Purpose: It is used to load a pre-configured GitHub storage block that contains settings for accessing a GitHub repository. This block is often used to pull flow code from a GitHub repository when deploying or running flows. - Configuration: The block would typically include details such as the repository URL, branch, and any necessary authentication credentials like access tokens. Unfortunately, specific documentation excerpts on
GitHub.load
were not available, but you can refer to Prefect's storage guide for more information on configuring storage blocks, including those for GitHub. If you are using
GitHub.load
in your code, ensure that the GitHub block is correctly configured in Prefect's UI or CLI, and it includes all necessary credentials and settings for accessing your repository.
v
@Marvin how do i setup prefect automation in prefect 2.X to retry automatically when it sees error like this Flow could not be retrieved from deployment. OSError: Failed to pull from remote:
m
To set up Prefect 2.x to automatically retry when encountering errors like "Flow could not be retrieved from deployment" due to issues pulling from a remote repository, you can follow these steps: ### Implementing Automatic Retries for Deployment Failures 1. Custom Code Retrieval Logic with Retries: Since Prefect's default deployment mechanism doesn't inherently support retries for remote code retrieval, you can implement a custom solution using Python's retry capabilities. 2. Use a Retry Library: Leverage a Python retry library such as
tenacity
to add retry logic around the code retrieval process. This can help handle transient network issues or temporary unavailability of the remote repository. 3. Example Implementation:
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python
    import subprocess
    import time
    from tenacity import retry, stop_after_attempt, wait_fixed

    @retry(stop=stop_after_attempt(3), wait=wait_fixed(10))
    def clone_repository(repo_url):
        result = subprocess.run(["git", "clone", repo_url], capture_output=True, text=True)
        if result.returncode != 0:
            raise OSError(f"Failed to pull from remote:\n {result.stderr}")

    # Usage
    try:
        clone_repository("<https://github.com/your-repo.git>")
    except OSError as e:
        print(f"Retry attempts failed with error: {e}")
4. Integrate with Prefect Deployment: If you have control over the deployment script or the environment where Prefect runs, integrate this retry logic into the setup phase before the flow execution starts. 5. Monitoring and Alerts: Set up monitoring and alerting to notify you if retries fail after the maximum attempts. This ensures you can manually intervene if persistent issues occur. ### Additional Considerations - Network Reliability: Ensure that network conditions are stable and check if there are any known issues with the remote repository service. - Access Credentials: Verify that all necessary credentials and permissions are correctly configured for accessing the remote repository. For more detailed guidance, you can refer to Prefect's deployment documentation and explore community discussions on Prefect's GitHub issues.
v
@Marvin, I am using prefect 2.X . In Prefect UI how do i create automation trigger to pass flow run id to a different flow when first one is in failed state
m
To create an automation in Prefect 2.x that triggers another flow upon the failure of a flow run, you can use Prefect Cloud's automation features. Here's how you can set it up: ### Steps to Create an Automation Trigger in Prefect UI 1. Access Automations in Prefect Cloud: - Navigate to the Automations page in the Prefect Cloud UI. This is where you can configure actions based on specific trigger conditions. 2. Define a Trigger Condition: - Set a trigger condition for when a flow run enters a "Failed" state. This can be done by selecting the appropriate event that corresponds to a flow run's state change to "Failed." 3. Configure the Automation Action: - Choose an action that runs another flow. You can specify the flow you want to trigger and pass necessary parameters, such as the
flow_run_id
of the failed flow, to this subsequent flow. 4. Pass Flow Run ID: - Ensure that the triggered flow is set up to accept parameters. You can pass the
flow_run_id
of the failed flow as a parameter to the new flow. This can be done by configuring the action to include the flow run ID in the parameters when triggering the new flow. 5. Save and Activate the Automation: - Save the automation configuration and ensure it is activated so that it automatically responds to the specified trigger conditions. ### Additional Considerations - Prefect Cloud Requirement: Automations are available in Prefect Cloud, providing a flexible framework for automatically responding to events. - Custom Logic: You can also define custom triggers using webhooks or Python code if needed. For more detailed guidance, refer to the Prefect Automations documentation to explore the full capabilities and examples of setting up automations.
v
@Marvin for the action part i am using { "flow_run_id": "{{ prefect.resource.id }}" } but my flow is unable to get the flow id.
m
In Prefect 2.x, when setting up an automation to pass the
flow_run_id
to another flow, you need to ensure that the Jinja templating syntax is correctly used to access the flow run properties. Here's how you can correctly configure the action part of your automation to pass the `flow_run_id`: ### Correct Usage of
flow_run_id
in Automations 1. Jinja Template Syntax: Ensure you are using the correct syntax to access the flow run ID. In Prefect, you can use Jinja templating to access properties of the flow run object. 2. Example Configuration:
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json
   {
     "flow_run_id": "{{ flow_run.id }}"
   }
3. Verify Automation Setup: Double-check that your automation is correctly configured in the Prefect UI to trigger on the appropriate event (e.g., a flow entering a "Failed" state). 4. Debugging: If the flow is unable to receive the
flow_run_id
, ensure that the triggered flow is set up to accept parameters and that there are no issues with the Jinja templating in your automation configuration. ### Additional Considerations - Flow Parameters: Ensure that the flow you are triggering is designed to accept parameters, including the
flow_run_id
. - Testing: Test the automation with a controlled failure scenario to ensure that the
flow_run_id
is correctly passed and received by the triggered flow. For more detailed guidance, refer to the Prefect Automations documentation for examples and further explanations on using Jinja templates within automations.
v
@Marvin i am getting following error when i passed the above paramter Validation of flow parameters failed with error: Traceback (most recent call last): File "/usr/local/lib/python3.11/site-packages/prefect/engine.py", line 423, in retrieve_flow_then_begin_flow_run parameters = flow.validate_parameters(flow_run.parameters) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.11/site-packages/prefect/flows.py", line 423, in validate_parameters raise ParameterTypeError.from_validation_error(exc) from None prefect.exceptions.ParameterTypeError: Flow run received invalid parameters: - flow_run_id: field required i have defined my flow like this @flow(name = 'abc', persist_result=True,log_prints=True,result_storage=az_block) async def abc(flow_run_id: str):
m
The error you're encountering indicates that the
flow_run_id
parameter is not being correctly passed to the flow, and it is required by your flow definition. Here are some steps to troubleshoot and resolve the issue: ### Steps to Resolve the Parameter Passing Issue 1. Ensure Parameter is Passed: Confirm that the automation is correctly configured to pass the
flow_run_id
. The Jinja template should be
{ "flow_run_id": "{{ flow_run.id }}" }
, and it should be applied in the context where the flow is triggered. 2. Check Flow Definition: Your flow definition seems correct in requiring
flow_run_id
as a parameter. Make sure that the flow is registered and deployed with this parameter requirement. 3. Update Automation Configuration: - Double-check the automation setup in Prefect Cloud to ensure that it's correctly configured to trigger and pass parameters. - Verify that the Jinja template syntax is correct and that it's being used in the right place within the automation. 4. Test with a Direct Call: As a test, manually trigger the flow with the required parameter to ensure that the flow itself is correctly set up to accept and process the
flow_run_id
. 5. Debugging: - Check the logs or any error messages in the Prefect UI to ensure that the automation is firing as expected. - Ensure that the flow run triggering the automation has a valid
flow_run.id
to pass. ### Example Manual Call for Testing
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python
from prefect import flow

@flow(name='abc', persist_result=True, log_prints=True, result_storage=az_block)
async def abc(flow_run_id: str):
    # Your flow logic here
    print(f"Received flow run ID: {flow_run_id}")

# Test the flow manually
abc(flow_run_id="test-flow-run-id")
By following these steps, you should be able to diagnose where the parameter passing is failing and ensure that the
flow_run_id
is correctly passed to your flow. If the issue persists, consider reviewing the automation setup in the Prefect UI for any misconfigurations.