<@ULVA73B9P> I have a case, I want to deploy my pr...
# ask-community
j
@Marvin I have a case, I want to deploy my prefect project in a docker container. But on documentation I only find the case for a file with a simple workflow. I am not a docker expert but If any could help me with this I'd glad this is my docker file
Copy code
# Use an official Python runtime as a parent image
FROM python:3.10-slim

# Add our requirements.txt file to the image and install dependencies
COPY requirements.txt .
COPY src/ /src/
# Install any needed packages specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt
WORKDIR /src
EXPOSE 4200
# Run our flow script when the container starts
CMD ["python", "workflow.py"]
what I expect is a docker container running a server with the flow deployed and with the schedules ready:
Copy code
@flow
def main_flow(
    mlflow_path: str = "sqlite:///mlflow/mlflow.db",
    experiment: str = "random-forest",
) -> None:
    """The main training pipeline"""
    datasets = load_data()
    best_hyper_params = train_model(datasets)
    <http://logging.info|logging.info>(f"Best hyperparameters: {best_hyper_params}")
    register_model(mlflow_path, experiment)



if __name__ == "__main__":
    main_flow.serve(
        name="src", 
        cron="*/2 * * * *",
        tags=["mlops", "tracking"],
        description="keep track on the model performance",
        version="0.1.0",
        )
The above code depends on several other file, like utils, other task and so on. so I need to deploy, but when I run this I got an error
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docker run --network="host" -e PREFECT_API_URL=<http://host.docker.internal:4200/api> workflow
the error is httpx.ConnectError: All connection attempts failed httpcore.ConnectError: All connection attempts failed
m
Your message was too long by 118 tokens - please shorten it and try again. For reference, here's your message at the allowed limit:
I have a case, I want to deploy my prefect project in a docker container. But on documentation I only find the case for a file with a simple workflow. I am not a docker expert but If any could help me with this I'd glad
this is my docker file
Copy code
# Use an official Python runtime as a parent image
FROM python:3.10-slim

# Add our requirements.txt file to the image and install dependencies
COPY requirements.txt .
COPY src/ /src/
# Install any needed packages specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt
WORKDIR /src
EXPOSE 4200
# Run our flow script when the container starts
CMD ["python", "workflow.py"]
what I expect is a docker container running a server with the flow deployed and with the schedules ready: ```@flow def main_flow( mlflow_path: str = "sqlite:///mlflow/mlflow.db", experiment: str = "random-forest", ) -> None: """The main training pipeline""" datasets = load_data() best_hyper_params = train_model(datasets) logging.info(f"Best hyperparameters: {best_hyper_params}") register_model(mlflow_path, experiment) if name == "__main__": main_flow.serve( name="src", cron="*/2 * * * *",
j
@Marvin I have a case, I want to deploy my prefect project in a docker container. But on documentation I only find the case for a file with a simple workflow. I am not a docker expert but If any could help me with this I'd glad This is my docker file
Copy code
# Use an official Python runtime as a parent image
FROM python:3.10-slim
# Add our requirements.txt file to the image and install dependencies
COPY requirements.txt .
COPY src/ /src/
# Install any needed packages specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt
WORKDIR /src
EXPOSE 4200
# Run our flow script when the container starts
CMD ["python", "workflow.py"]
what I expect is a docker container running a server with the flow deployed and with the schedules ready:
Copy code
@flow
def main_flow(
    mlflow_path: str = "sqlite:///mlflow/mlflow.db",
    experiment: str = "random-forest",
) -> None:
    """The main training pipeline"""

if __name__ == "__main__":
    main_flow.serve(
        name="src", 
        cron="*/2 * * * *",
        tags=["mlops", "tracking"],
        description="keep track on the model performance",
        version="0.1.0",
        )
so I need to deploy, but when I run this I got an error
Copy code
docker run --network="host" -e PREFECT_API_URL=<http://host.docker.internal:4200/api> workflow
errors: httpx.ConnectError: All connection attempts failed httpcore.ConnectError: All connection attempts failed
m
Your message was too long by 49 tokens - please shorten it and try again. For reference, here's your message at the allowed limit:
I have a case, I want to deploy my prefect project in a docker container. But on documentation I only find the case for a file with a simple workflow. I am not a docker expert but If any could help me with this I'd glad
This is my docker file
Copy code
# Use an official Python runtime as a parent image
FROM python:3.10-slim
# Add our requirements.txt file to the image and install dependencies
COPY requirements.txt .
COPY src/ /src/
# Install any needed packages specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt
WORKDIR /src
EXPOSE 4200
# Run our flow script when the container starts
CMD ["python", "workflow.py"]
what I expect is a docker container running a server with the flow deployed and with the schedules ready:
Copy code
@flow
def main_flow(
    mlflow_path: str = "sqlite:///mlflow/mlflow.db",
    experiment: str = "random-forest",
) -> None:
    """The main training pipeline"""

if __name__ == "__main__":
    main_flow.serve(
        name="src", 
        cron="*/2 * * * *",
        tags=["mlops", "tracking"],
        description="keep track on the model performance",
        version="0.1.0",
        )
so I need to deploy, but when I run this I got an error ```
j
@Marvin I have a case, I want to deploy my prefect project in a docker container. But on documentation I only find the case for a file with a simple workflow. I am not a docker expert but If any could help me with this I'd glad This is my docker file
Copy code
# Use an official Python runtime as a parent image
FROM python:3.10-slim
# Add our requirements.txt file to the image and install dependencies
COPY requirements.txt .
COPY src/ /src/
# Install any needed packages specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt
WORKDIR /src
EXPOSE 4200
# Run our flow script when the container starts
CMD ["python", "workflow.py"]
what I expect is a docker container running a server with the flow deployed and with the schedules ready:
Copy code
if __name__ == "__main__":
    main_flow.serve(
        name="src", 
        cron="*/2 * * * *",
        tags=["mlops", "tracking"],
        description="keep track on the model performance",
        version="0.1.0",
        )
so I need to deploy, but when I run this I got an error
Copy code
docker run --network="host" -e PREFECT_API_URL=<http://host.docker.internal:4200/api> workflow
errors: httpx.ConnectError: All connection attempts failed httpcore.ConnectError: All connection attempts failed
m
Your message was too long by 2 tokens - please shorten it and try again. For reference, here's your message at the allowed limit:
I have a case, I want to deploy my prefect project in a docker container. But on documentation I only find the case for a file with a simple workflow. I am not a docker expert but If any could help me with this I'd glad
This is my docker file
Copy code
# Use an official Python runtime as a parent image
FROM python:3.10-slim
# Add our requirements.txt file to the image and install dependencies
COPY requirements.txt .
COPY src/ /src/
# Install any needed packages specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt
WORKDIR /src
EXPOSE 4200
# Run our flow script when the container starts
CMD ["python", "workflow.py"]
what I expect is a docker container running a server with the flow deployed and with the schedules ready:
Copy code
if __name__ == "__main__":
    main_flow.serve(
        name="src", 
        cron="*/2 * * * *",
        tags=["mlops", "tracking"],
        description="keep track on the model performance",
        version="0.1.0",
        )
so I need to deploy, but when I run this I got an error
Copy code
docker run --network="host" -e PREFECT_API_URL=<http://host.docker.internal:4200/api> workflow
errors: httpx.ConnectError: All connection attempts failed httpcore.ConnectError: All connection
j
@Marvin I want to deploy my prefect project in a docker container. But on documentation I only find the case for a file with a simple workflow. I am not a docker expert but If any could help me with this I'd glad This is my docker file
Copy code
# Use an official Python runtime as a parent image
FROM python:3.10-slim
# Add our requirements.txt file to the image and install dependencies
COPY requirements.txt .
COPY src/ /src/
# Install any needed packages specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt
WORKDIR /src
EXPOSE 4200
# Run our flow script when the container starts
CMD ["python", "workflow.py"]
what I expect is a docker container running a server with the flow deployed and with the schedules ready:
Copy code
if __name__ == "__main__":
    main_flow.serve(
        name="src", 
        cron="*/2 * * * *",
        tags=["mlops", "tracking"],
        description="keep track on the model performance",
        version="0.1.0",
        )
so I need to deploy, but when I run this I got an error
Copy code
docker run --network="host" -e PREFECT_API_URL=<http://host.docker.internal:4200/api> workflow
errors: httpx.ConnectError: All connection attempts failed httpcore.ConnectError: All connection attempts failed
m
To deploy your Prefect project inside a Docker container and avoid the connection error, follow these revised steps: 1. Dockerfile Adjustment: Your
Dockerfile
is mostly correct, but make sure you install Prefect and any required packages in
requirements.txt
. Additionally, ensure the Prefect environment variable is set properly within the container.
Copy code
dockerfile
    # Use an official Python runtime as a parent image
    FROM python:3.10-slim

    # Set the working directory
    WORKDIR /src

    # Add our requirements.txt file to the image
    COPY requirements.txt .

    # Install any needed packages specified in requirements.txt
    RUN pip install --no-cache-dir -r requirements.txt

    # Copy source code to the image
    COPY src/ /src/

    # Expose Prefect API port
    EXPOSE 4200

    # Set environment variables for Prefect
    ENV PREFECT_API_URL=<http://host.docker.internal:4200/api>

    # Run our flow script when the container starts
    CMD ["python", "workflow.py"]
2. Project Structure: Make sure your project structure is correct:
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my_project/
    ├── Dockerfile
    ├── requirements.txt
    └── src/
        └── workflow.py
3. Running Docker Container: Use the
docker run
command to set the network mode to
host
and pass the environment variable.
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sh
    docker run --network="host" -e PREFECT_API_URL=<http://host.docker.internal:4200/api> my_project
4. Additional Notes: - Ensure Docker is running and properly configured on your machine. - Verify that Prefect’s API URL (
PREFECT_API_URL
) is correct and accessible from within the Docker container. - Depending on your network configuration,
host.docker.internal
might need to be replaced with the actual IP address or a different host. For further details, refer to the links provided for more information on Prefect Deployment and Configuring a Prefect Server Instance. If the issue persists, consider checking Prefect's GitHub issues for similar problems like HTTP connection errors. Good luck! Let me know if you need more help.
j
@Marvin keep the same error I try to change it to ENV PREFECT_API_URL=http://127.0.0.1:4200/api remember I am trying to get localhost
m
Got it, let's try to address the connection issue more effectively. Prefect running inside a Docker container may not correctly resolve
localhost
or
127.0.0.1
as the host machine. In Docker, using
host.docker.internal
is typically recommended for accessing host services, but this can sometimes be tricky depending on the Docker setup (especially on Linux). Here are some steps to debug and potentially resolve the issue: 1. Ensure Docker Network Configuration: Make sure Docker is set to use the Docker network
host
mode. However, this is not supported on Docker for Mac or Windows directly, and solutions may vary across different operating systems. 2. Verify Connectivity: Before proceeding, ensure you can ping
host.docker.internal
from within your Docker container, and it resolves correctly:
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sh
   docker run -it --rm --network="host" my_project ping -c 4 host.docker.internal
3. Use Docker Compose: Sometimes using Docker Compose for more controlled networking might be better. Here is a basic example using Docker Compose. docker-compose.yml:
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yaml
    version: '3.8'

    services:
      workflow:
        build: .
        environment:
          - PREFECT_API_URL=<http://host.docker.internal:4200/api>
        network_mode: "host"
        ports:
          - "4200:4200"
4. Modify Dockerfile for Enhanced Debugging: Adding a simple script to run before your flow to ensure connectivity: src/entrypoint.sh:
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sh
    #!/bin/sh

    # Wait for Prefect API to be ready
    until curl -s <http://host.docker.internal:4200/api/health;> do
      >&2 echo "Prefect API is unavailable - sleeping"
      sleep 1
    done

    >&2 echo "Prefect API is up - executing command"
    exec "$@"
Dockerfile:
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dockerfile
    # Use an official Python runtime as a parent image
    FROM python:3.10-slim

    # Set the working directory
    WORKDIR /src

    # Add our requirements.txt file to the image
    COPY requirements.txt .

    # Install any needed packages specified in requirements.txt
    RUN pip install --no-cache-dir -r requirements.txt

    # Copy source code to the image
    COPY src/ /src/
    
    # Add the entrypoint script
    RUN chmod +x /src/entrypoint.sh

    # Expose Prefect API port
    EXPOSE 4200

    # Set environment variables for Prefect
    ENV PREFECT_API_URL=<http://host.docker.internal:4200/api>

    # Run the entrypoint script
    ENTRYPOINT ["/src/entrypoint.sh"]

    # Run our flow script when the container starts
    CMD ["python", "workflow.py"]
5. Using Docker Compose to Run: Finally, use Docker Compose to run your container:
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sh
   docker-compose up
These steps should help ensure that your Docker container can correctly connect to the Prefect API running on the host machine. If the problem persists, we might need to dive deeper into Docker networking configurations for your specific OS. For more detailed information, refer to Prefect Configuration with Docker and the GitHub issues like Indirect Connectivity Issues.
j
no, at the end I get Prefect API is unavailable - sleeping
@Marvin no, at the end I get Prefect API is unavailable - sleeping
m
Alright, let's tackle the issue where your Docker container cannot connect to the Prefect API. Here are a few additional steps to ensure that the Prefect API is accessible from within the Docker container: 1. Ensure Prefect Server is Running: Ensure that your Prefect API server is indeed running and accessible from your host. You should be able to access
<http://127.0.0.1:4200/api/health>
from your host machine's browser or use `curl`:
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sh
   curl <http://127.0.0.1:4200/api/health>
2. Use Host Networking with Docker: On some systems (like Linux), host networking is required. If you are using Docker on Linux, you can use
host
networking to directly access services running on your host machine:
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sh
   docker run --network="host" -e PREFECT_API_URL=<http://127.0.0.1:4200/api> my_project
3. Check Docker Network: Ensure your Prefect server and Docker container use the same Docker network. You can create a custom bridge network and connect both to it:
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sh
   docker network create prefect_network
   docker run -d --network=prefect_network --name prefect_server -p 4200:4200 prefecthq/prefect:2-python3.10 prefect server start
   docker run --network=prefect_network -e PREFECT_API_URL=<http://prefect_server:4200/api> my_project
4. Docker Compose: Using Docker Compose can ensure services start in the required order and are on the same network: docker-compose.yml:
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yaml
   version: '3.8'
   
   services:
     prefect_server:
       image: prefecthq/prefect:2-python3.10
       command: prefect server start
       ports:
         - "4200:4200"
       networks:
         - prefect_network

     workflow:
       build: .
       environment:
         - PREFECT_API_URL=<http://prefect_server:4200/api>
       networks:
         - prefect_network

   networks:
     prefect_network:
       driver: bridge
5. Update Entrypoint Script: src/entrypoint.sh:
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sh
    #!/bin/sh

    # Wait for Prefect API to be ready
    while ! nc -z prefect_server 4200; do
      >&2 echo "Prefect API is unavailable - sleeping"
      sleep 1
    done

    >&2 echo "Prefect API is up - executing command"
    exec "$@"
6. Update Dockerfile: Dockerfile:
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dockerfile
    # Use an official Python runtime as a parent image
    FROM python:3.10-slim

    # Set the working directory
    WORKDIR /src

    # Add our requirements.txt file to the image
    COPY requirements.txt .

    # Install any needed packages specified in requirements.txt
    RUN pip install --no-cache-dir -r requirements.txt

    # Copy source code to the image
    COPY src/ /src/
    
    # Add the entrypoint script
    RUN chmod +x /src/entrypoint.sh

    # Determine default shell
    SHELL ["/bin/sh", "-c"]

    # Set environment variables for Prefect
    ENV PREFECT_API_URL=<http://prefect_server:4200/api>

    # Run the entrypoint script
    ENTRYPOINT ["/src/entrypoint.sh"]

    # Run our flow script when the container starts
    CMD ["python", "workflow.py"]
7. Run Docker Compose:
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sh
    docker-compose up --build
This approach ensures that both Prefect Server and your workflow script are on the same network and can communicate with each other. If these steps still don't work, consider exploring detailed network setup logs and Docker networking documentation for the specific OS being used.
j
@Marvin can I start a server on docker?
m
Yes, you can start a Prefect server within a Docker container. Below is a step-by-step guide to set up a Prefect server and your workflow in separate Docker containers using Docker Compose: ### 1. Create Directory Structure Ensure your project directory structure looks like this:
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my_project/
├── docker-compose.yml
├── Dockerfile
├── requirements.txt
└── src/
    ├── workflow.py
    └── entrypoint.sh
### 2. Docker Compose File Create a
docker-compose.yml
file to start both the Prefect server and your workflow container: docker-compose.yml:
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yaml
version: '3.8'
services:
  prefect_server:
    image: prefecthq/prefect:2-python3.10
    command: prefect server start
    ports:
      - "4200:4200"
    networks:
      - prefect_network

  workflow:
    build: .
    environment:
      - PREFECT_API_URL=<http://prefect_server:4200/api>
    networks:
      - prefect_network

networks:
  prefect_network:
    driver: bridge
### 3. Dockerfile Update your
Dockerfile
to install necessary dependencies and copy your source code: Dockerfile:
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dockerfile
# Use an official Python runtime as a parent image
FROM python:3.10-slim

# Set the working directory
WORKDIR /src

# Add our requirements.txt file to the image
COPY requirements.txt .

# Install any needed packages specified in requirements.txt
RUN pip install --no-cache-dir -r requirements.txt

# Copy source code to the image
COPY src/ /src/

# Add the entrypoint script
COPY src/entrypoint.sh /usr/local/bin/entrypoint.sh
RUN chmod +x /usr/local/bin/entrypoint.sh

# Expose Prefect API port
EXPOSE 4200

# Run the entrypoint script
ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]

# Run our flow script when the container starts
CMD ["python", "workflow.py"]
### 4. Entrypoint Script Create an entrypoint script to wait for the Prefect server to be available before running your workflow: src/entrypoint.sh:
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sh
#!/bin/sh

# Function to test if Prefect server API is up
wait_for_prefect_server() {
  while ! curl -s $PREFECT_API_URL/health; do
    >&2 echo "Prefect API is unavailable - sleeping"
    sleep 1
  done
}

# Wait for Prefect API
wait_for_prefect_server

>&2 echo "Prefect API is up - executing command"
exec "$@"
### 5. Requirements File Include Prefect and any other dependencies in your `requirements.txt`: requirements.txt:
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prefect==2.0.0
### 6. Workflow Script Ensure your workflow script (
workflow.py
) is properly structured. For example: src/workflow.py:
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python
from prefect import flow

@flow
def main_flow():
    print("Flow is running!")

if __name__ == "__main__":
    main_flow.serve(
        name="src", 
        cron="*/2 * * * *",
        tags=["mlops", "tracking"],
        description="keep track on the model performance",
        version="0.1.0",
    )
### 7. Run Docker Compose Finally, use Docker Compose to build and start your containers:
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sh
docker-compose up --build
This setup will ensure that the Prefect server and your workflow container are started together, and your workflow will wait until the Prefect server is ready before executing. Please adjust the version numbers and package names in
requirements.txt
based on your specific needs. Let me know if you have any further questions or issues!