Short answer: yes. Point your Prefect worker container at a JSON logging config so it emits structured logs to stdout, then let ECS/FireLens ship them to Datadog. Here’s the simplest, reliable way in Prefect 3.x. 1) Add a Prefect logging config that uses the JSON formatter Create a file (e.g.,

/etc/prefect/logging.yml

) in the worker image:

version: 1
disable_existing_loggers: false

formatters:
  json:
    (): prefect.logging.formatters.JsonFormatter
    # "default" is compact; "pretty" adds indentation
    format: "default"

handlers:
  console:
    class: logging.StreamHandler
    level: DEBUG
    formatter: json
    stream: <ext://sys.stdout>

  # Optional: still send logs to Prefect API
  api:
    class: prefect.logging.handlers.APILogHandler
    level: INFO

  # Worker-specific API handler
  worker_api:
    class: prefect.logging.handlers.WorkerAPILogHandler
    level: INFO

loggers:
  # Worker logs (what you asked about)
  prefect.workers:
    level: INFO
    handlers: [console, worker_api]  # drop worker_api if you do NOT want logs in Prefect
    propagate: false

  # Core Prefect logs
  prefect:
    level: INFO
    handlers: [console]
    propagate: false

root:
  level: INFO
  handlers: [console]

Notes - This uses Prefect’s built-in

JsonFormatter

so each log line is a JSON object (includes fields like

severity

,

flow_run_id

,

task_run_id

, etc. when applicable). - If you do not want any logs sent to Prefect’s API, remove `worker_api`/`api` handlers and/or set the env var noted below. 2) Point Prefect at that config and disable color/markup Add these environment variables to your ECS worker task definition:

PREFECT_LOGGING_SETTINGS_PATH=/etc/prefect/logging.yml
PREFECT_LOGGING_COLORS=false
PREFECT_LOGGING_MARKUP=false
# Optional: if you do NOT want logs in Prefect’s API as well
# PREFECT_LOGGING_TO_API_ENABLED=false

3) Ensure ECS sends stdout/stderr to Datadog - If you use CloudWatch Logs: use the

awslogs

driver and Datadog’s CloudWatch log forwarder. - If you use FireLens/Fluent Bit (recommended for direct ingest): configure the worker container with

awsfirelens

and a log router sidecar. Example (FireLens to Datadog) snippet in the worker task definition:

{
  "containerDefinitions": [
    {
      "name": "prefect-worker",
      "image": "prefecthq/prefect:3-latest",
      "essential": true,
      "command": [
        "prefect",
        "worker",
        "start",
        "--pool",
        "my-ecs-pool"
      ],
      "environment": [
        {
          "name": "PREFECT_LOGGING_SETTINGS_PATH",
          "value": "/etc/prefect/logging.yml"
        },
        {
          "name": "PREFECT_LOGGING_COLORS",
          "value": "false"
        },
        {
          "name": "PREFECT_LOGGING_MARKUP",
          "value": "false"
        }
      ],
      "logConfiguration": {
        "logDriver": "awsfirelens",
        "options": {
          "Name": "datadog",
          "apikey": "<DATADOG_API_KEY>",
          "provider": "ecs",
          "service": "prefect-worker",
          "env": "prod"
        }
      },
      "mountPoints": [
        {
          "sourceVolume": "prefect-config",
          "containerPath": "/etc/prefect"
        }
      ]
    },
    {
      "name": "log-router",
      "image": "amazon/aws-for-fluent-bit:latest",
      "essential": true,
      "firelensConfiguration": {
        "type": "fluentbit"
      }
    }
  ],
  "volumes": [
    {
      "name": "prefect-config",
      "host": {
        "sourcePath": "/path/on/host/with/logging.yml"
      }
    }
  ]
}

Practical tips - Put the

logging.yml

in your worker image (or mount it as a volume) and set

PREFECT_LOGGING_SETTINGS_PATH

to that location. - The same approach works for flow-run containers too. If you also want structured logs from your flows, include the same file and env var in the image used by your deployments. - Keep

colors=false

and

markup=false

to avoid escape codes that would break JSON parsing. - Datadog will automatically parse the JSON and surface your custom attributes (e.g.,

flow_run_id

,

task_run_id

, etc.) for filtering and dashboards. References

- Prefect logging components (JsonFormatter, handlers): JsonFormatter source and logging package - ECS worker docs: Prefect AWS ECS worker Want me to tailor a minimal

logging.yml

and task definition patch based on your current ECS task JSON and how you’re sending logs to Datadog (CloudWatch forwarder vs FireLens)?