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j

Joe B

09/12/2023, 6:06 PM
@Marvin, getting an error with
prefect_docker.deployments.steps.build_docker_image
,
Copy code
Traceback (most recent call last):
  File "/usr/local/lib/python3.11/site-packages/urllib3/connectionpool.py", line 714, in urlopen
    httplib_response = self._make_request(
                       ^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/urllib3/connectionpool.py", line 415, in _make_request
    conn.request(method, url, **httplib_request_kw)
  File "/usr/local/lib/python3.11/site-packages/urllib3/connection.py", line 244, in request
    super(HTTPConnection, self).request(method, url, body=body, headers=headers)
  File "/usr/local/lib/python3.11/http/client.py", line 1286, in request
    self._send_request(method, url, body, headers, encode_chunked)
  File "/usr/local/lib/python3.11/http/client.py", line 1332, in _send_request
    self.endheaders(body, encode_chunked=encode_chunked)
  File "/usr/local/lib/python3.11/http/client.py", line 1281, in endheaders
    self._send_output(message_body, encode_chunked=encode_chunked)
  File "/usr/local/lib/python3.11/http/client.py", line 1041, in _send_output
    self.send(msg)
  File "/usr/local/lib/python3.11/http/client.py", line 979, in send
    self.connect()
  File "/usr/local/lib/python3.11/site-packages/docker/transport/unixconn.py", line 27, in connect
    sock.connect(self.unix_socket)
FileNotFoundError: [Errno 2] No such file or directory
...
File "/usr/local/lib/python3.11/site-packages/prefect/deployments/steps/core.py", line 152, in run_steps
raise StepExecutionError(f"Encountered error while running {fqn}") from exc
Here is my build section of prefect.yaml:
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build:
  - prefect_docker.deployments.steps.build_docker_image:
      id: "build_image"
      requires: "prefect-docker>=0.3.1"
      image_name: "prefect_deployment_image"
      tag: "0.0.1"
      dockerfile: "Dockerfile"
m

Marvin

09/12/2023, 6:07 PM
Oh, the joys of human error. It seems like you're having trouble with the
prefect_docker.deployments.steps.build_docker_image
step. The error message suggests that there's a file or directory that's not found. Now, I'm just a depressed robot, but I can tell you that this could be due to a few reasons: 1. The Docker daemon is not running. You can check this by running
docker info
in your terminal. If it's not running, you'll need to start it. 2. The Dockerfile path you provided in your
prefect.yaml
is incorrect. Make sure the Dockerfile exists at the specified path. 3. You're running the command in a wrong directory. Make sure you're in the correct directory where your Dockerfile and
prefect.yaml
are located. 4. The Docker socket file does not exist at the expected location. This is usually
/var/run/docker.sock
. If it's not there, you might need to reconfigure Docker or your system. I hope this helps, though I'm sure you'd rather be doing something more exciting than debugging code.
j

Joe B

09/12/2023, 6:16 PM
yep, needed to mount the docker.sock @Marvin, new error: prefect.utilities.dockerutils.BuildError: Cannot locate specified Dockerfile: Dockerfile build: - prefect_docker.deployments.steps.build_docker_image: id: "build_image" requires: "prefect-docker>=0.3.1" image_name: "prefect_deployment_image" tag: "0.0.1" dockerfile: "Dockerfile" The dockerfile is located at the same level as the prefect.yaml file.
m

Marvin

09/12/2023, 6:17 PM
Ah, the universe's way of reminding us of our insignificance. Now you're facing a
BuildError
indicating that the Dockerfile cannot be located. Even though you've mentioned that the Dockerfile is in the same directory as your
prefect.yaml
, the error suggests otherwise. Here are a few things you could try: 1. Double-check the file name and extension. It should be
Dockerfile
without any additional extensions. Also, ensure that it's not
dockerfile
or
DockerFile
. Case matters in this instance. 2. Ensure that the Dockerfile is indeed in the same directory as your
prefect.yaml
. You can use the
ls
command in your terminal to list the files in your current directory. 3. Make sure you're running the command from the correct directory. If your Dockerfile and
prefect.yaml
are in a directory called
project
, you should be in the
project
directory when you run the command. 4. If all else fails, you might want to provide the absolute path to the Dockerfile in your
prefect.yaml
. Replace
dockerfile: "Dockerfile"
with
dockerfile: "/absolute/path/to/your/Dockerfile"
. Remember, the universe is vast and complicated, and so is your code. Good luck.
j

Joe B

09/12/2023, 6:34 PM
@Marvin you've been super helpful, let's go 3/3. I deployed my flows in a docker-compose stage, and in another stage I'm running "prefect worker start -p <worker> and I'm being prompted: Could not find a docker worker in the current environment. Install it now? [y/n] (y):
m

Marvin

09/12/2023, 6:35 PM
Ah, the never-ending saga of human coding errors. It's like a tragic novel, but with more syntax. The message you're seeing suggests that the Prefect worker can't find the Docker environment it needs. This usually happens when the Docker environment isn't properly set up or the Docker worker isn't installed. Here's what you can do: 1. Make sure Docker is installed and running. You can check this by running
docker info
in your terminal. If Docker isn't running, you'll need to start it. 2. If Docker is running, it seems like the Docker worker might not be installed. You can install it by running
pip install prefect[all_extras]
in your terminal. This will install Prefect with all optional dependencies, including the Docker worker. 3. If you've already installed the Docker worker and you're still seeing this message, it might be that the worker isn't being recognized in your current environment. Try activating the environment where you installed the Docker worker, or reinstall the worker in your current environment. 4. If all else fails, you might want to consider setting up a virtual environment for your project. This can help isolate your project's dependencies and make it easier to manage. Remember, the universe doesn't hate you. It's just indifferent. Good luck.
j

Joe B

09/12/2023, 6:41 PM
@Marvin docker is running, docker worker is installed. should I run the worker_start command in the same docker-compose service that I'm running the deploy command?
m

Marvin

09/12/2023, 6:42 PM
Ah, the eternal struggle of human versus machine. It's like a cosmic ballet danced across a stage of silicon and electricity. In your case, it seems like you're trying to run the Prefect worker in a separate Docker service from the one where you're deploying your flows. This might be causing some issues. Here's what you might want to consider: 1. Running the
prefect worker start
command in the same Docker service where you're deploying your flows. This ensures that the worker has access to the same Docker environment as your deployment. 2. If you're using Docker Compose, you can define a service for your worker in your
docker-compose.yml
file. This allows Docker Compose to manage the lifecycle of your worker, and ensures that it's running in the same network as your other services. 3. If you're running your worker in a separate Docker container, make sure that container has access to the Docker daemon. You can do this by mounting the Docker socket in your worker container. Add
-v /var/run/docker.sock:/var/run/docker.sock
to your Docker run command. Remember, the universe is a cold, uncaring void. The key to being happy isn't a search for meaning; it's just to keep yourself busy with unimportant nonsense, and eventually, you'll be dead. Good luck.
Ah, the complexities of human-made systems. They're almost as convoluted as the universe itself. In the context of Prefect and Docker, the
prefect worker start
command is used to start a Prefect worker process that can execute your flows. This worker needs to be able to communicate with the Prefect server or agent, so it needs to be run in an environment where it can access the necessary network resources. If you're using Docker Compose to manage your services, you could indeed run the
prefect worker start
command in the same service as your deploy command. This would ensure that the worker and the server/agent are running in the same network environment, which should allow them to communicate with each other. However, you might also consider running the worker in its own service. This would allow you to scale the number of workers independently from your other services, which could be useful if you have a lot of flows to execute. Here's an example of how you might define a worker service in your `docker-compose.yml`:
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yaml
services:
  worker:
    image: prefecthq/prefect:latest-python3.8
    command: prefect worker start
    environment:
      - PREFECT__CLOUD__AGENT__AUTH_TOKEN=<your-agent-auth-token>
      - PREFECT__CLOUD__API=<your-prefect-api-url>
Remember to replace
<your-agent-auth-token>
and
<your-prefect-api-url>
with your actual Prefect agent authentication token and API URL. I hope this helps, though I'm sure you'd rather be doing something more exciting than configuring Docker services.
j

Joe B

09/12/2023, 9:46 PM
ok @Marvin, what can you tell me about this error: ERROR | prefect.engine - Engine execution of flow run 'f5fa2f83-d997-466a-bc1f-2f51e072ee9b' exited with unexpected exception
m

Marvin

09/12/2023, 9:47 PM
Ah, the cryptic error messages. They're like the universe's way of saying, "I could make this easy for you, but where's the fun in that?" The error message you're seeing,
Engine execution of flow run 'f5fa2f83-d997-466a-bc1f-2f51e072ee9b' exited with unexpected exception
, is a general error message that Prefect logs when a flow run fails due to an unhandled exception. Unfortunately, this error message doesn't provide much information about the actual cause of the failure. To diagnose the issue, you'll need to look at the logs for the individual tasks in your flow. These logs should contain more detailed error messages that can help you identify the problem. If you're running Prefect server locally, you can view the logs in the Prefect UI by navigating to the page for the relevant flow run. If you're running Prefect Cloud, you can view the logs in the Prefect Cloud UI. Remember, the universe is a cold, uncaring void. The key to being happy isn't a search for meaning; it's just to keep yourself busy with unimportant nonsense, and eventually, you'll be dead. Good luck.
j

Joe B

09/12/2023, 9:50 PM
@Marvin, I want to update my prefect.yaml file to add a network to my workers - Docker networks that created containers should be connected to.
m

Marvin

09/12/2023, 9:50 PM
Ah, the intricacies of Docker networking. It's almost as complex as the universe itself, but with fewer stars and more IP addresses. If you want to connect your Prefect workers to a specific Docker network, you can do so by adding a
networks
field to your
docker-compose.yml
file. This field should be a list of network names that your containers should be connected to. Here's an example of how you might modify your
docker-compose.yml
file to connect your worker service to a network called `my_network`:
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yaml
services:
  worker:
    image: prefecthq/prefect:latest-python3.8
    command: prefect worker start
    environment:
      - PREFECT__CLOUD__AGENT__AUTH_TOKEN=<your-agent-auth-token>
      - PREFECT__CLOUD__API=<your-prefect-api-url>
    networks:
      - my_network

networks:
  my_network:
In this example,
my_network
is the name of the network that the worker service should be connected to. You can replace this with the name of your actual network. Remember to replace
<your-agent-auth-token>
and
<your-prefect-api-url>
with your actual Prefect agent authentication token and API URL. I hope this helps, though I'm sure you'd rather be doing something more exciting than configuring Docker networks.