@Marvin create me an async function that will use get_docker_container_logs and stream the logs from the container. Also the logger (logger = get_run_logger()) should not wait for the entire logs but should continuously print them in the UI

To create an async function that fetches and streams Docker container logs with Prefect and continuously prints them to the UI, we will need to combine the capabilities of fetching Docker logs and utilizing Prefect's logging system effectively. Below is an example code to achieve this:

python
import asyncio
from prefect import flow, get_run_logger, task
from prefect_docker.containers import get_docker_container_logs

@task
async def stream_container_logs(container_name: str):
    logger = get_run_logger()

    async for log_line in get_docker_container_logs(container_name=container_name, stream=True):
        <http://logger.info|logger.info>(log_line)

@flow(log_prints=True)
async def docker_logs_flow(container_name: str):
    await stream_container_logs(container_name)

if __name__ == "__main__":
    asyncio.run(docker_logs_flow(container_name="your_container_name"))

In the code above: 1. The

stream_container_logs

task uses

get_docker_container_logs

with

stream=True

to fetch logs continuously. 2. The

logger

obtained via

get_run_logger()

logs the incoming log lines. 3. The

docker_logs_flow

flow calls the task and can be run with

asyncio.run

. You can check out these resources for more details: - Prefect Docker Containers Documentation: https://docs.prefect.io/latest/integrations/prefect-docker/containers/ - Prefect Logging Guide: https://docs.prefect.io/latest/guides/logs/ - Prefect Async Code Example: https://raw.githubusercontent.com/zzstoatzz/prefect-code-examples/main/examples/flows/async_basic.py

@Marvin so in this example you show should I pass as param the container name I want prefect to stream the logs?

Yes, you should pass the container name as a parameter to the

docker_logs_flow

so that Prefect knows which Docker container's logs to stream. Here's how you can pass the container name:

python
import asyncio
from prefect import flow, get_run_logger, task
from prefect_docker.containers import get_docker_container_logs

@task
async def stream_container_logs(container_name: str):
    logger = get_run_logger()

    async for log_line in get_docker_container_logs(container_name=container_name, stream=True):
        <http://logger.info|logger.info>(log_line)

@flow(log_prints=True)
async def docker_logs_flow(container_name: str):
    await stream_container_logs(container_name)

if __name__ == "__main__":
    # Pass the container name as a parameter to the flow
    container_name = "your_container_name"  # Replace with your specific container name
    asyncio.run(docker_logs_flow(container_name=container_name))

In the

docker_logs_flow(container_name)

call, replace

"your_container_name"

with the name of the Docker container you want Prefect to stream logs from. This way, the

docker_logs_flow

will receive the container name and pass it to the

stream_container_logs

task, which then uses it to fetch and stream the logs.

@Marvin it failed with the following: prefect.exceptions.ParameterBindError: Error binding parameters for function 'get_docker_container_logs': missing a required argument: 'container_id'. Function 'get_docker_container_logs' has signature 'container_id: str, docker_host: Optional[prefect_docker.host.DockerHost] = None, **logs_kwargs: Dict[str, Any]) -> str' but received args: () and kwargs: ['container_name', 'stream']. 191601.500 | ERROR | Flow run 'pumpkin-deer' - Finished in state Failed("Flow run encountered an exception: ParameterBindError: Error binding parameters for function 'get_docker_container_logs': missing a required argument: 'container_id'.\nFunction 'get_docker_container_logs' has signature 'container_id: str, docker_host: Optional[prefect_docker.host.DockerHost] = None, **logs_kwargs: Dict[str, Any]) -> str' but received args: () and kwargs: ['container_name', 'stream'].") 191601.501 | ERROR | prefect.engine - Engine execution of flow run '5a9fad86-e977-4242-8233-6cefcde4f949' exited with unexpected exception Traceback (most recent call last):

The

get_docker_container_logs

function requires the container ID (

container_id

) rather than the container name (

container_name

). Let's update the code to use the container ID:

python
import asyncio
from prefect import flow, get_run_logger, task
from prefect_docker.containers import get_docker_container_logs

@task
async def stream_container_logs(container_id: str):
    logger = get_run_logger()

    async for log_line in get_docker_container_logs(container_id=container_id, stream=True):
        <http://logger.info|logger.info>(log_line)

@flow(log_prints=True)
async def docker_logs_flow(container_id: str):
    await stream_container_logs(container_id)

if __name__ == "__main__":
    # Pass the container ID as a parameter to the flow
    container_id = "your_container_id"  # Replace with your specific container ID
    asyncio.run(docker_logs_flow(container_id=container_id))

In the

docker_logs_flow(container_id)

call, replace

"your_container_id"

with the ID of the Docker container you want Prefect to stream logs from. For more information, you can refer to the Prefect Docker Containers Documentation.

@Marvin I get the following error: 192143.027 | ERROR | Task run 'stream_container_logs-0' - Task run failed with exception: TypeError("'async for' requires an object with aiter method, got coroutine") - Retries are exhausted 192143.037 | ERROR | Task run 'stream_container_logs-0' - Finished in state Failed("Task run encountered an exception TypeError: 'async for' requires an object with aiter method, got coroutine") 192143.038 | ERROR | Flow run 'lurking-dragon' - Encountered exception during execution: TypeError("'async for' requires an object with aiter method, got coroutine") async for log_line in get_docker_container_logs(container_id=container_id, stream=True):

It seems the issue arises because

get_docker_container_logs

in Prefect is not directly iterable in an

async for

loop like typical async generators. We need to handle the coroutine properly. Below is the revised code with proper handling:

python
import asyncio
from prefect import flow, get_run_logger, task
from prefect_docker.containers import get_docker_container_logs

@task
async def fetch_container_logs(container_id: str):
    # Fetch logs as a complete coroutine
    logs = await get_docker_container_logs(container_id=container_id, stream=True)
    return logs

@task
def stream_logs(logs: str):
    logger = get_run_logger()
    for log_line in logs.splitlines():
        <http://logger.info|logger.info>(log_line)

@flow(log_prints=True)
async def docker_logs_flow(container_id: str):
    raw_logs = await fetch_container_logs(container_id)
    stream_logs(raw_logs)

if __name__ == "__main__":
    # Pass the container ID as a parameter to the flow
    container_id = "your_container_id"  # Replace with your specific container ID
    asyncio.run(docker_logs_flow(container_id=container_id))

1.

fetch_container_logs

task fetches all logs as a single coroutine. 2.

stream_logs

task processes and logs each line. 3.

docker_logs_flow

orchestrates these tasks. Replace

"your_container_id"

with the actual container ID you want to fetch logs from. This should solve the coroutine handling and logging issues.

@Marvin ERROR | Task run 'get_docker_container_logs-0' - Task run failed with exception: AttributeError("'CancellableStream' object has no attribute 'decode'") - Retries are exhausted ERROR | Task run 'get_docker_container_logs-0' - Finished in state Failed("Task run encountered an exception AttributeError: 'CancellableStream' object has no attribute 'decode'") ERROR | Task run 'fetch_container_logs-0' - Task run failed with exception: AttributeError("'CancellableStream' object has no attribute 'decode'") - Retries are exhausted AttributeError: 'CancellableStream' object has no attribute 'decode' Task run 'fetch_container_logs-0' - Finished in state Failed("Task run encountered an exception AttributeError: 'CancellableStream' object has no attribute 'decode'") ERROR | Flow run 'fluorescent-goldfish' - Encountered exception during execution: AttributeError("'CancellableStream' object has no attribute 'decode'") ERROR | Flow run 'fluorescent-goldfish' - Finished in state Failed("Flow run encountered an exception: AttributeError: 'CancellableStream' object has no attribute 'decode'") ERROR | prefect.engine - Engine execution of flow run '3176fb8c-d5fc-466e-8de4-857d4edc94e6' exited with unexpected exception

Your message was too long by 46 tokens - please shorten it and try again. For reference, here's your message at the allowed limit:

192928.871 | ERROR | Task run 'get_docker_container_logs-0' - Task run failed with exception: AttributeError("'CancellableStream' object has no attribute 'decode'") - Retries are exhausted

192928.882 | ERROR | Task run 'get_docker_container_logs-0' - Finished in state Failed("Task run encountered an exception AttributeError: 'CancellableStream' object has no attribute 'decode'") 192928.882 | ERROR | Task run 'fetch_container_logs-0' - Task run failed with exception: AttributeError("'CancellableStream' object has no attribute 'decode'") - Retries are exhausted AttributeError: 'CancellableStream' object has no attribute 'decode' 192928.893 | ERROR | Task run 'fetch_container_logs-0' - Finished in state Failed("Task run encountered an exception AttributeError: 'CancellableStream' object has no attribute 'decode'") 192928.893 | ERROR | Flow run 'fluorescent-goldfish' - Encountered exception during execution: AttributeError("'CancellableStream' object has no attribute 'decode'") 192928.908 | ERROR | Flow run 'fluorescent-goldfish' - Finished in state Failed("Flow run encountered an exception: AttributeError: 'CancellableStream' object has no attribute 'decode'") 19:29

@Marvin I get this: 193433.998 | ERROR | Flow run 'attentive-rook' - Encountered exception during execution: AttributeError("'CancellableStream' object has no attribute 'decode'") AttributeError: 'CancellableStream' object has no attribute 'decode' 193434.013 | ERROR | Flow run 'attentive-rook' - Finished in state Failed("Flow run encountered an exception: AttributeError: 'CancellableStream' object has no attribute 'decode'") 193434.014 | ERROR | prefect.engine - Engine execution of flow run '39b27857-7e65-49f3-9e66-20b607d8c95c' exited with unexpected exception AttributeError: 'CancellableStream' object has no attribute 'decode'

The error indicates that the

CancellableStream

object returned by

get_docker_container_logs

requires specific handling, as it doesn't directly yield strings that can be decoded or logged. To properly handle the

CancellableStream

, we need to iterate over its content correctly. The

CancellableStream

most likely yields byte chunks which can be converted to strings. Here's the updated code to handle this scenario appropriately:

python
import asyncio
from prefect import flow, get_run_logger, task
from prefect_docker.containers import get_docker_container_logs

@task
async def stream_container_logs(container_id: str):
    logger = get_run_logger()

    async for log_chunk in (await get_docker_container_logs(container_id=container_id, stream=True)):
        log_line = log_chunk.decode("utf-8")
        <http://logger.info|logger.info>(log_line)

@flow(log_prints=True)
async def docker_logs_flow(container_id: str):
    await stream_container_logs(container_id)

if __name__ == "__main__":
    # Pass the container ID as a parameter to the flow
    container_id = "your_container_id"  # Replace with your specific container ID
    asyncio.run(docker_logs_flow(container_id=container_id))

In this version: 1. We decode each

log_chunk

yielded by the

CancellableStream

using

utf-8

. 2. Each decoded line is logged using Prefect's logger. Make sure to replace

"your_container_id"

with the actual Docker container ID. This should correctly handle the streaming logs and handle

CancellableStream

objects.

in this code: import asyncio from prefect import flow, get_run_logger, task from prefect_docker.containers import get_docker_container_logs @task def stream_logs(logs: list): logger = get_run_logger() decoded_logs = [log.decode('utf-8') for log in logs] # Decode the entire list of logs using utf-8 for decoded_log in decoded_logs: # Process the decoded log line logger.info(decoded_log) @flow(log_prints=True) async def docker_logs_flow(container_id: str): all_logs = await get_docker_container_logs(stream=True, container_id=container_id) # Use await log_rows = [log.decode('utf-8') for log in all_logs] # Decode each log line using utf-8 stream_logs(log_rows) # Process the retrieved logs here if name == "__main__": # Pass the container ID as a parameter to the flow container_id = "4f523f70fb51" # Replace with your specific container ID asyncio.run(docker_logs_flow(container_id=container_id)) @Marvin help me fix AttributeError: 'CancellableStream' object has no attribute 'decode'

The issue you're encountering stems from trying to decode the entire

CancellableStream

object, which isn't directly consumable in a list comprehension or in a simple

for

loop. Instead, you need to iterate over the stream as it yields byte strings. Let's break it down into correctly handling the

CancellableStream

object and decoding the chunks properly. Here's the corrected version:

python
import asyncio
from prefect import flow, get_run_logger, task
from prefect_docker.containers import get_docker_container_logs

@task
async def fetch_container_logs(container_id: str):
    logs = []
    async for log_chunk in (await get_docker_container_logs(container_id=container_id, stream=True)):
        logs.append(log_chunk)
    return logs

@task
def stream_logs(logs: list):
    logger = get_run_logger()
    for log in logs:
        decoded_log = log.decode('utf-8')  # Decode using utf-8
        <http://logger.info|logger.info>(decoded_log)

@flow(log_prints=True)
async def docker_logs_flow(container_id: str):
    logs = await fetch_container_logs(container_id)  # Gather logs
    stream_logs(logs)  # Process the retrieved logs

if __name__ == "__main__":
    # Pass the container ID as a parameter to the flow
    container_id = "your_container_id"  # Replace with your specific container ID
    asyncio.run(docker_logs_flow(container_id=container_id))

In this version: 1. `fetch_container_logs`: This task collects all log chunks asynchronously. 2. `stream_logs`: This task decodes each log chunk and logs it. 3. `docker_logs_flow`: This flow coordinates both tasks. Replace

"your_container_id"

with the actual Docker container ID. This setup ensures that you correctly handle the

CancellableStream

and decode each log chunk properly.