@Marvin how do I get logs from my flow execution running in ECS Fargate to Cloudwatch?

It appears that custom configuration might be needed to ensure that logs from your flow execution in ECS Fargate are sent to CloudWatch. According to Prefect's blog post, most AWS services send logs to CloudWatch automatically, but services like AWS Lambda and ECS can suffer from a lack of observability. To get logs from ECS Fargate to Cloudwatch, you would typically use AWS's built-in capabilities for log streaming. You can set up the AWS Fargate task definition with the

awslogs

log driver and specify the correct log group and region in CloudWatch. Here is an example of a logging configuration in a task definition:

json
"logging": {
    "logDriver": "awslogs",
    "options": {
        "awslogs-group": "your-log-group",
        "awslogs-region": "your-region",
        "awslogs-stream-prefix": "ecs"
    }
}

You'll need to ensure that your ECS task execution role has the necessary permissions to send logs to CloudWatch. If the executions aren't showing up in CloudWatch, you may need to look into the task definition and role permissions. For more specific information in the context of Prefect, you may want to look into the Prefect documentation for logging and observability, or reach out to the community for how others have integrated Prefect flows with CloudWatch logs.

@Marvin, I do this for our agent, where we control the task definition. But for the flows the agent is creating the task definition for us, and in that definition this is not set. How do I set it for the definition which is created for a flow run?

When using Prefect with ECS Fargate, the agent generates the task definitions for flow runs, which may not initially include the desired log configuration. According to information from Prefect's documentation on logs, you may be able to override logging configurations using environment variables or Prefect Profile settings. You can set these variables to configure the logging behavior for your flows. The important aspect here is that you would need to use the appropriate syntax:

PREFECT_LOGGING_[PATH]_[TO]_[KEY]

, where

[PATH]_[TO]_[KEY]

corresponds to the nested address of the setting you want to change. However, specific documentation on how to add AWS CloudWatch logging configurations to the task definitions generated by the Prefect ECS agent was not found in the search results. I would recommend reaching out to the Prefect community or examining the ECS agent source code to determine how to inject custom logging settings into the automatically generated task definitions. In the meantime, you might also consider contributing to the Prefect discussions or raising an issue in their GitHub repository if this functionality seems to be lacking or unclear. For more in-depth assistance, please refer to the following resources: - Prefect Logging Guide - Prefect Community Slack - Prefect GitHub Issues