Slackbot
09/16/2024, 1:15 AMMarvin
09/16/2024, 1:16 AMacocodes
09/16/2024, 1:26 AMMarvin
09/16/2024, 1:26 AMdeploy
function to create these deployments. Each project can have its configurations, dependencies, and workflows. Here’s an example to illustrate creating multiple deployments:
python
from prefect import deploy, flow
@flow(log_prints=True)
def buy():
print("Buying securities")
@flow(log_prints=True)
def sell():
print("Selling securities")
if __name__ == "__main__":
deploy(
buy.to_deployment(name="buy-deploy", work_pool_name="my-docker-pool"),
sell.to_deployment(name="sell-deploy"),
image="my-registry/my-image:dev",
push=False,
)
More on Multiple Deployments
#### 2. Using CI/CD for Deployment Management
For complex projects, especially those using monorepos or multiple environments, integrating Prefect with GitHub Actions or another CI/CD tool helps maintain a smooth workflow. Deployments can be automatically selected based on conditions such as branch changes or folder modifications:
yaml
on:
push:
branches:
- stg
- main
paths:
- "project_1/**"
Example Repository with CI/CD Workflow
#### 3. Concurrency Management
When dealing with multiple tasks or flows, managing concurrency ensures you do not exceed resource limits. Prefect provides concurrency limits to control the number of tasks running in parallel:
python
from prefect.concurrency.sync import concurrency
@task
def database_query(query):
with concurrency("database", occupy=1):
# execute query
...
Concurrency Limits
#### 4. Organizing Workspaces
Workspaces in Prefect can be used to separate environments like staging and production. This approach allows you to isolate the changes and impacts of your deployments.
yaml
- stg
- main
#### 5. Dynamic vs. Static Infrastructure
Choose between static infrastructure (long-lived) or dynamic infrastructure (scalable) based on your use case. Using the serve
method on the Flow object is a good fit for managing multiple flows on static infrastructure.
Static vs. Dynamic Infrastructure
### References:
1. Deploy to CI/CD Workspaces
2. Concurrency Management
3. Managing Deployments
These best practices should help you keep your Prefect projects organized and running smoothly! If you need more specific information, feel free to ask.acocodes
09/16/2024, 1:30 AMMarvin
09/16/2024, 1:31 AMmain_project_directory/
├── project_1/
│ ├── flows/
│ └── prefect.yaml
└── project_2/
├── flows/
└── prefect.yaml
2. Sample prefect.yaml
File:
Each project will have its own prefect.yaml
that defines its deployment.
project_1/prefect.yaml:
yaml
name: project_1
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
project_2/prefect.yaml:
yaml
name: project_2
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
3. Deploying Projects:
Use the Prefect CLI to deploy each project locally. Navigate to each project's directory and run the deployment command.
bash
cd main_project_directory/project_1
prefect deployment build --apply
bash
cd main_project_directory/project_2
prefect deployment build --apply
4. Using CI/CD for Automated Deployments:
Set up CI/CD pipelines (e.g., GitHub Actions) to handle automatic deployments when changes are pushed. Here’s a simple example using GitHub Actions:
.github/workflows/deploy-projects.yaml:
yaml
name: Deploy Projects
on:
push:
branches:
- main
jobs:
deploy_project_1:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '3.8'
- name: Install Prefect
run: pip install prefect
- name: Deploy Project 1
run: |
cd project_1
prefect deployment build --apply
deploy_project_2:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '3.8'
- name: Install Prefect
run: pip install prefect
- name: Deploy Project 2
run: |
cd project_2
prefect deployment build --apply
This setup keeps each project self-contained while still benefiting from the shared structure of a parent directory. It also simplifies automation with CI/CD tools.
For more information and detailed examples, you can refer to the Prefect 3.x documentation on deployments and best practices:
- Deploy via YAML
- Infrastructure Examples
If you have any more specific questions or need further assistance setting up your projects, let me know!acocodes
09/16/2024, 1:32 AMMarvin
09/16/2024, 1:32 AMmain_project_directory/
├── project_1/
│ ├── flows/
│ ├── requirements.txt
│ └── prefect.yaml
└── project_2/
├── flows/
├── requirements.txt
└── prefect.yaml
### Sample prefect.yaml
Files
You would need to modify each prefect.yaml
file to include steps to install the dependencies specified in the requirements.txt
.
project_1/prefect.yaml:
yaml
name: project_1
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
pull_steps:
- prefect.infrastructure.steps.ProcessEnv:
env:
PIP_INSTALL: "pip install -r ./requirements.txt"
project_2/prefect.yaml:
yaml
name: project_2
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
pull_steps:
- prefect.infrastructure.steps.ProcessEnv:
env:
PIP_INSTALL: "pip install -r ./requirements.txt"
### Deploying Projects with Requirements
When deploying each project, Prefect will automatically run the pip install
command to install the dependencies listed in requirements.txt
.
### Automating with CI/CD
Here’s a simple example of how to set up GitHub Actions to handle the deployments and install the requirements for each project:
.github/workflows/deploy-projects.yaml:
yaml
name: Deploy Projects
on:
push:
branches:
- main
jobs:
deploy_project_1:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '3.8'
- name: Install Prefect
run: pip install prefect
- name: Install Project 1 Requirements
run: |
cd project_1
pip install -r requirements.txt
- name: Deploy Project 1
run: |
cd project_1
prefect deployment build --apply
deploy_project_2:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '3.8'
- name: Install Prefect
run: pip install prefect
- name: Install Project 2 Requirements
run: |
cd project_2
pip install -r requirements.txt
- name: Deploy Project 2
run: |
cd project_2
prefect deployment build --apply
### Conclusion
By using the pull_steps
section in prefect.yaml
, each project can define what needs to be done to set up its environment, including installing its requirements. This way, you maintain independent environments for each project even when deploying from a shared CI/CD pipeline.
For further reading, you can check:
- Prefect Deployment Guide
- CI/CD with Prefect
If you have more questions or need further details, feel free to ask!acocodes
09/16/2024, 1:45 AMprefect.yaml
, is it possible to not call the flow directly? I'm using argparse to dynamically define flow inputs based on config arguments.Marvin
09/16/2024, 1:45 AMargparse
to dynamically define the flow inputs based on config arguments. Here's how you can do it:
### Example Structure
In each project folder, create a script (e.g., run_flow.py
) that handles argument parsing and flow execution:
plaintext
main_project_directory/
├── project_1/
│ ├── flows/
│ ├── prefect.yaml
│ ├── requirements.txt
│ └── run_flow.py
└── project_2/
├── flows/
├── prefect.yaml
├── requirements.txt
└── run_flow.py
### Sample run_flow.py
with argparse
project_1/run_flow.py:
python
import argparse
from prefect import flow
@flow
def my_flow(my_param):
print(f"Flow received parameter: {my_param}")
def main():
parser = argparse.ArgumentParser(description="Run Prefect flow with dynamic parameters.")
parser.add_argument("--my_param", type=str, required=True, help="Parameter for the flow.")
args = parser.parse_args()
my_flow(args.my_param)
if __name__ == "__main__":
main()
### prefect.yaml
Configuration
Modify your prefect.yaml
to use run_flow.py
as the entry point:
project_1/prefect.yaml:
yaml
name: project_1
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
pull_steps:
- prefect.infrastructure.steps.ProcessEnv:
env:
PIP_INSTALL: "pip install -r ./requirements.txt"
entrypoint: "run_flow.py"
By setting the entry point to your custom script, Prefect will run run_flow.py
, which can use argparse
to handle dynamic input parameters.
### Deploying the Project
You can then deploy the project as usual:
bash
cd main_project_directory/project_1
prefect deployment build --apply
#### Automating with CI/CD
.github/workflows/deploy-projects.yaml:
yaml
name: Deploy Projects
on:
push:
branches:
- main
jobs:
deploy_project_1:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '3.8'
- name: Install Prefect
run: pip install prefect
- name: Install Project 1 Requirements
run: |
cd project_1
pip install -r requirements.txt
- name: Deploy Project 1
run: |
cd project_1
prefect deployment build --apply
deploy_project_2:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '3.8'
- name: Install Prefect
run: pip install prefect
- name: Install Project 2 Requirements
run: |
cd project_2
pip install -r requirements.txt
- name: Deploy Project 2
run: |
cd project_2
prefect deployment build --apply
### Conclusion
This setup allows you to dynamically define flow inputs using argparse
within a custom script, facilitating complex workflows and dynamic configurations.
For more details, refer to:
- Prefect Deployment Guide
- Prefect CLI Commands
Let me know if you need further assistance!acocodes
09/16/2024, 2:21 AMMissingFlowError
if I try to call the entire python fileMarvin
09/16/2024, 2:21 AMMissingFlowError
occurs because Prefect requires an explicit flow definition in the entry point to identify and register the flow. Instead of calling the entire Python file, you need to specify the exact flow to Prefect.
### Solution: Modify Prefect CLI Command in Deployment Script
To work around this, use a script to handle argparse
and then call this script separately in your CI/CD pipeline or execution environment rather than as the entry point in Prefect.
Here's how you can do it correctly:
### Directory Structure
Your directory structure remains the same:
main_project_directory/
├── project_1/
│ ├── flows/
│ ├── prefect.yaml
│ ├── requirements.txt
│ └── run_flow.py
└── project_2/
├── flows/
├── prefect.yaml
├── requirements.txt
└── run_flow.py
### run_flow.py
with argparse
Keep your custom script for handling argparse
as is:
python
# project_1/run_flow.py
import argparse
from prefect import flow
@flow
def my_flow(my_param):
print(f"Flow received parameter: {my_param}")
def main():
parser = argparse.ArgumentParser(description="Run Prefect flow with dynamic parameters.")
parser.add_argument("--my_param", type=str, required=True, help="Parameter for the flow.")
args = parser.parse_args()
my_flow(args.my_param)
if __name__ == "__main__":
main()
### Prefect Deployment Script
In prefect.yaml
, you will specify the flow directly. Define a simpler script that Prefect can execute to register the flow:
project_1/prefect.yaml:
yaml
name: project_1
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
pull_steps:
- prefect.infrastructure.steps.ProcessEnv:
env:
PIP_INSTALL: "pip install -r ./requirements.txt"
entrypoint: "flows.my_flow"
### Deployment Process Using CI/CD
.github/workflows/deploy-projects.yaml:
yaml
name: Deploy Projects
on:
push:
branches:
- main
jobs:
deploy_project_1:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '3.8'
- name: Install Prefect
run: pip install prefect
- name: Install Project 1 Requirements
run: |
cd project_1
pip install -r requirements.txt
- name: Deploy Project 1
run: |
cd project_1
prefect deployment build --apply
deploy_project_2:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '3.8'
- name: Install Prefect
run: pip install prefect
- name: Install Project 2 Requirements
run: |
cd project_2
pip install -r requirements.txt
- name: Deploy Project 2
run: |
cd project_2
prefect deployment build --apply
### Running the Flows
To run the flows and pass dynamic parameters, execute run_flow.py
separately in your execution environment:
bash
cd main_project_directory/project_1
python run_flow.py --my_param value
### Conclusion
Prefect requires the exact flow to be specified at deployment for registration purposes. Use a separate script to handle dynamic parameters (run_flow.py
), and call this script separately when you run your flows.
For more information, you can refer to:
- Prefect Deployment Guide
- Prefect CLI Commands
Let me know if you need further assistance!acocodes
09/16/2024, 2:24 AMMarvin
09/16/2024, 2:28 AMprefect.yaml
file is correctly configured with the necessary fields.
Example `prefect.yaml`:
yaml
name: project_1
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
pull_steps:
- prefect.infrastructure.steps.ProcessEnv:
env:
PIP_INSTALL: "pip install -r ./requirements.txt"
entrypoint: "flows.my_flow"
2. Dependency Issues:
Ensure all dependencies specified in the requirements.txt
are installed correctly.
requirements.txt:
plaintext
prefect
any_other_dependency
3. File Paths and Import Errors:
Check that all file paths and imports are correct. Ensure the entrypoint
in prefect.yaml
points to the correct flow.
4. Invalid Flow Definition:
Ensure the flow defined in your Python script matches the expected format. Prefect tries to identify the flow based on the entrypoint
.
5. Permission Issues:
Ensure that the Prefect agent running the deployment has permission to access all required resources (files, network, etc.).
### Troubleshooting Steps
#### 1. Verify prefect.yaml
File
Make sure that the prefect.yaml
file is correctly formatted and contains all required fields.
#### 2. Check Error Logs
Look at the error logs provided by Prefect Cloud. The logs can give detailed insight into what went wrong.
#### 3. Simplify Your Deployment
Start with a minimal prefect.yaml
and gradually add complexity to isolate the issue.
Minimal `prefect.yaml`:
yaml
name: project_1
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
entrypoint: "flows.my_flow"
#### 4. Test Locally
Before deploying to Prefect Cloud, test the entire setup locally.
bash
cd main_project_directory/project_1
prefect deployment build --apply
prefect agent start
Run the flow locally to ensure it works:
bash
python run_flow.py --my_param value
#### 5. Validate Environment Setup
Ensure that the environment where your flow runs has all required dependencies. This might include setting up a virtual environment.
#### 6. Handle Exit Codes in CI/CD
Make sure that your CI/CD pipeline captures and logs the error details if the deployment fails.
Example GitHub Action:
yaml
name: Deploy Projects
on:
push:
branches:
- main
jobs:
deploy_project_1:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Set up Python
uses: actions/setup-python@v2
with:
python-version: '3.8'
- name: Install Prefect
run: pip install prefect
- name: Install Project 1 Requirements
run: |
cd project_1
pip install -r requirements.txt
- name: Deploy Project 1
run: |
cd project_1
prefect deployment build --apply || exit 1
### Conclusion
Diagnosing deployment issues can be tricky without the exact error message, but the above steps and best practices should help you troubleshoot common problems. If the issue persists, please check the detailed logs from Prefect Cloud or try simplifying your prefect.yaml
.
For further insight:
- Prefect Deployment Guide
Feel free to share more details or specific error messages if you need more targeted assistance!acocodes
09/16/2024, 3:27 AMprefect.yaml
, it isn't foundMarvin
09/16/2024, 3:28 AMentrypoint
. However, you can structure your code to work around this.
Here's how you can proceed:
### Example Class with Flow Method
First, let's define a class with a flow method.
python
# project_1/flows/my_module.py
from prefect import flow
class MyClass:
@flow
def my_flow(self, my_param):
print(f"Flow received parameter: {my_param}")
### Workaround: Wrapper Function
Since Prefect expects a standalone function as the entry point, you can create a wrapper function that instantiates the class and calls the class method.
python
# project_1/flows/wrapper.py
from .my_module import MyClass
def run_my_class_flow(my_param):
instance = MyClass()
instance.my_flow(my_param)
### prefect.yaml
Configuration
Set the entry point in prefect.yaml
to point to the wrapper function, not the class method directly.
project_1/prefect.yaml:
yaml
name: project_1
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
pull_steps:
- prefect.infrastructure.steps.ProcessEnv:
env:
PIP_INSTALL: "pip install -r ./requirements.txt"
entrypoint: "flows.wrapper.run_my_class_flow"
### Deployment and Running the Flow
1. Build and Apply Deployment:
bash
cd main_project_directory/project_1
prefect deployment build ./flows/wrapper.py:run_my_class_flow --apply
2. Trigger the Flow:
Now you can trigger the flow as you normally would, and it will call the class method via the wrapper function.
### Running with Arguments
To run the flow with dynamic arguments, you would handle this in your CI/CD or execution environment. The flow would be triggered with the necessary parameters in your wrapper function.
Example:
bash
python -c "from flows.wrapper import run_my_class_flow; run_my_class_flow(my_param='value')"
### Conclusion
Using a wrapper function to call the class method allows Prefect to recognize the function specified in the entrypoint
field of your prefect.yaml
. This approach maintains the object-oriented design while satisfying Prefect's requirement for an entry point.
For more information:
- Prefect Deployment Guide
- Prefect CLI Commands
Let me know if you need more help!acocodes
09/16/2024, 3:50 AMUnicodeEncodeError
when trying to run a simple deployment:
File "C:\Program Files\Python311\Lib\encodings\cp1252.py", line 19, in encode
return codecs.charmap_encode(input,self.errors,encoding_table)[0]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeEncodeError: 'charmap' codec can't encode characters in position 0-2: character maps to <undefined> (edited)Marvin
09/16/2024, 4:52 AMUnicodeEncodeError
when trying to run a simple deployment:
File "C:\Program Files\Python311\Lib\encodings\cp1252.py", line 19, in encode
return codecs.charmap_encode(input,self.errors,encoding_table)[0]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeEncodeError: 'charmap' codec can't encode characters in position 0-2: character maps to <undefined>
The UnicodeEncodeError
you're encountering typically occurs when handling non-ASCII characters in environments set to use cp1252
encoding (common in Windows). This issue can arise during string processing, especially if there are special characters or non-ASCII characters in your script or configurations.
### Solutions
1. Set Environment Variable:
You can set the PYTHONIOENCODING
environment variable to utf-8
to ensure your Python scripts use UTF-8 encoding.
Command Line:
cmd
set PYTHONIOENCODING=utf-8
Permanently (Windows):
- Open Environment Variables (through System Properties).
- Add a new User or System variable: PYTHONIOENCODING
with value utf-8
.
2. Modify Python Script:
Force encoding within your script explicitly.
Example:
python
import sys
sys.stdout = open(sys.stdout.fileno(), mode='w', encoding='utf8', buffering=1)
sys.stderr = open(sys.stderr.fileno(), mode='w', encoding='utf8', buffering=1)
3. Check Source Files and Strings:
Ensure no special or non-ASCII characters exist inadvertently in your script or variables.
### Example Implementation
Here's an example on how to explicitly set encoding in a Python script.
project_1/flows/wrapper.py:
python
import sys
sys.stdout = open(sys.stdout.fileno(), mode='w', encoding='utf8', buffering=1)
sys.stderr = open(sys.stderr.fileno(), mode='w', encoding='utf8', buffering=1)
from .my_module import MyClass
def run_my_class_flow(my_param):
instance = MyClass()
instance.my_flow(my_param)
Running Deployment:
bash
cd main_project_directory/project_1
prefect deployment build ./flows/wrapper.py:run_my_class_flow --apply
### Changing Windows Console Code Page
Another option is to change the console code page to UTF-8 before running your script. This can be temporarily achieved by running:
cmd
chcp 65001
### Conclusion
Ensure that your environment and scripts explicitly handle UTF-8 encoding to avoid issues related to UnicodeEncodeError
. Setting environment variables, modifying your script to enforce UTF-8 encoding, and checking your source files for special characters should resolve the issue.
For further reference:
- Python Unicode HOWTO
- Prefect Deployment Guide
Let me know if these solutions help or if you need more assistance!Marvin
09/16/2024, 4:52 AMself
parameter is required. How do I rewrite code so this isn't required?
Seems like if I make a class method a flow, the self
parameter is required. How do I rewrite code so this isn't required?
If you prefer to avoid requiring the self
parameter within a class method defined as a Prefect flow, you can use class or static methods. These methods don't require an instance of the class (self
), making them easier to work with in some scenarios.
### Using Static Methods
A static method does not depend on the instance (self
) or class (cls
). It's essentially a regular function that resides within a class.
#### Example with Static Method
1. Define a Static Method in Your Class:
python
# project_1/flows/my_module.py
from prefect import flow
class MyClass:
@staticmethod
@flow
def my_flow(my_param):
print(f"Flow received parameter: {my_param}")
2. Wrapper Function:
python
# project_1/flows/wrapper.py
from .my_module import MyClass
def run_my_class_flow(my_param):
MyClass.my_flow(my_param)
3. Prefect YAML Configuration:
yaml
name: project_1
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
pull_steps:
- prefect.infrastructure.steps.ProcessEnv:
env:
PIP_INSTALL: "pip install -r ./requirements.txt"
entrypoint: "flows.wrapper.run_my_class_flow"
### Using Class Methods
A class method depends on the class (cls
), but not on a particular instance (self
). You can use them when you need to operate on the class itself.
#### Example with Class Method
1. Define a Class Method in Your Class:
python
# project_1/flows/my_module.py
from prefect import flow
class MyClass:
@classmethod
@flow
def my_flow(cls, my_param):
print(f"Flow received parameter: {my_param}")
2. Wrapper Function:
python
# project_1/flows/wrapper.py
from .my_module import MyClass
def run_my_class_flow(my_param):
MyClass.my_flow(my_param)
3. Prefect YAML Configuration:
yaml
name: project_1
version: 1
storage:
block: "local"
path: "./flows"
infrastructure:
type: "process"
pull_steps:
- prefect.infrastructure.steps.ProcessEnv:
env:
PIP_INSTALL: "pip install -r ./requirements.txt"
entrypoint: "flows.wrapper.run_my_class_flow"
### Summary
Using static or class methods avoids needing self
, making them useful for scenarios where you don’t require instance-specific data. You still get to keep your methods within a class for better organization while making Prefect deployments work seamlessly.
### Running Deployment
With these changes, build and apply the deployment as usual:
bash
cd main_project_directory/project_1
prefect deployment build ./flows/wrapper.py:run_my_class_flow --apply
For detailed information or more examples, refer to:
- Python Class Methods
- Python Static Methods
- Prefect Deployment Guide
Feel free to reach out if you need more assistance!