Arun Prasad
02/09/2024, 7:46 AMMarvin
02/09/2024, 7:46 AMArun Prasad
02/09/2024, 7:50 AMMarvin
02/09/2024, 7:50 AMArun Prasad
02/09/2024, 8:00 AMMarvin
02/09/2024, 8:00 AMArun Prasad
02/09/2024, 8:07 AMMarvin
02/09/2024, 8:08 AMArun Prasad
02/09/2024, 8:12 AMMarvin
02/09/2024, 8:12 AMArun Prasad
02/09/2024, 8:13 AMMarvin
02/09/2024, 8:13 AMArun Prasad
02/09/2024, 8:17 AMMarvin
02/09/2024, 8:17 AM@task
decorator. Flows are collections of tasks and define the workflow's structure, including task dependencies.
3. Composability: Prefect workflows are highly composable, meaning that tasks and flows can be modular, reused, and combined in various ways to build complex workflows.
4. Infrastructure Abstraction: Prefect offers infrastructure abstraction to various degrees depending on whether you're using the open-source or cloud version. Platform teams can customize interfaces and access to infrastructure without significant overhead.
Prefect's approach to workflow orchestration seeks to reduce mental overhead for developers and provide robustness in the presence of failures. To create workflows, developers need to handle errors gracefully, anticipate infrastructure issues, and design their workflows to be as fault-tolerant as possible.
Overall, the Prefect workflow definition language is designed to be highly readable and Python-driven, oriented towards simplicity, and maximizing developer productivity.
- A Platform Approach to Workflow Orchestration
For more detailed information about Prefect's workflow definition language and examples, you can explore Prefect's official documentation or engage with their community forums.Arun Prasad
02/09/2024, 8:32 AMMarvin
02/09/2024, 8:33 AMprefect deploy
).
Running Flows in Kubernetes: Once the deployments are successfully created, you can run them through the Prefect UI or the CLI (prefect deployment run
). The documentation specifically notes that while much of the deployment guidance is general for any Kubernetes cluster, some specifics may differ across cloud providers, particularly with container registries and access management, and provides a focus on Amazon EKS as an example.
Prerequisites: For setting up flows on Kubernetes using Prefect, you will need a Prefect Cloud account, a cloud provider account (AWS, GCP, or Azure), Python and Prefect installations, Helm, and the Kubernetes CLI (kubectl
).
Integration with Cloud Providers: Prefect's interaction with Kubernetes can be tied with various cloud providers, ensuring that you can use their managed Kubernetes services, such as EKS on AWS, GKE on Google Cloud, or AKS on Azure.
To get started and for comprehensive instructions on how to set up and use the Kubernetes executor with Prefect, you should refer to the official Prefect documentation regarding Kubernetes.Arun Prasad
02/09/2024, 8:34 AMMarvin
02/09/2024, 8:34 AMArun Prasad
02/09/2024, 8:36 AMMarvin
02/09/2024, 8:37 AMPREFECT_API_URL
environment variable so that your flow container can communicate with the Prefect API. If you're using Docker on Linux, you may need to use the --network="host"
option and set the PREFECT_API_URL
to <http://localhost:4200/api>
.
- Command example for running Docker: docker run --network="host" -e PREFECT_API_URL=<http://localhost:4200/api> your-prefect-image
4. Kubernetes Emulation:
- Utilize tools like Minikube, kind (Kubernetes IN Docker), or Docker Desktop's built-in Kubernetes cluster to run a local Kubernetes instance that can mimic the behavior of a managed Kubernetes service.
- Deploy the Prefect agent to your local Kubernetes cluster. Ensure it is configured correctly to pick up jobs from your Prefect Cloud or Server instance.
- Use kubectl
to interact with your local Kubernetes instance as you would with a cloud-hosted one.
5. Test and Debug:
- Use the Prefect CLI or UI to register and execute your flow.
- Monitor logs and output from the Kubernetes pods to inspect flow execution and debug as necessary.
This local setup will allow you to test how your flow would behave in a real Kubernetes environment, without having to deploy to a cloud service.
For further guidance, consult the Prefect documentation on deploying flows using Kubernetes and working with Docker containers.
Please note that this synopsis provides a sketch of the process. Specific commands and configuration may vary depending on your environment and setup.Arun Prasad
02/09/2024, 8:38 AMMarvin
02/09/2024, 8:39 AMArun Prasad
02/09/2024, 8:43 AMMarvin
02/09/2024, 8:43 AMJenkinsfile
or configured through the Jenkins web interface.
3. Prefect CLI: In the Jenkins pipeline steps, use Prefect's command-line interface (CLI) to register and deploy your flows. For example:
prefect register flow --file my_flow.py --project my_project
prefect deployment create my-flow-deployment.yaml
4. Trigger Jenkins Job: Configure a job in Jenkins that can be either manually triggered or set up with webhook triggers for automating flow deployments upon certain conditions, such as a push to a Git repository.
5. Monitoring: Monitor the output of the Jenkins job for any deployment issues and configure notifications for success or failure states.
To implement this, you must craft a Jenkins job that uses Prefect's CLI commands for deploying flows, similar to how you would use Prefect Cloud or Prefect Server. As the details can vary based on your specific setup and requirements, I recommend looking at both Prefect's CLI documentation and Jenkins' pipeline documentation to create a workflow that suits your needs.
Given that there's no direct example in the provided excerpts, for more specialized guidance on integrating Jenkins and Prefect, it may be helpful to consult the Prefect community or support forums, where other users might have shared similar experiences or to check the Prefect documentation for more on deploying flows, then adapt those instructions for a Jenkins environment.Arun Prasad
02/09/2024, 8:46 AMMarvin
02/09/2024, 8:47 AMArun Prasad
02/09/2024, 8:53 AMMarvin
02/09/2024, 8:54 AMArun Prasad
02/09/2024, 9:05 AMMarvin
02/09/2024, 9:06 AMArun Prasad
02/09/2024, 9:08 AMMarvin
02/09/2024, 9:09 AMArun Prasad
02/14/2024, 10:08 PMMarvin
02/14/2024, 10:09 PMArun Prasad
02/14/2024, 10:10 PMMarvin
02/14/2024, 10:10 PMArun Prasad
02/14/2024, 10:13 PMArun Prasad
02/14/2024, 10:15 PMMarvin
02/14/2024, 10:16 PMprefect server start
.
- Once the server is up, open a web browser and navigate to the Prefect server UI by going to the address <http://127.0.0.1:4200>
by default, or whatever URL is produced by the start command.
- In the UI, you’ll have an overview of all your Prefect flows. You can inspect individual flows to view their tasks and dependencies in a graphical format, often displayed as a Directed Acyclic Graph (DAG).
- The visual representation helps troubleshoot and understand the sequence and concurrency of task execution, as well as the current status of each task.
- Errors and logs can be checked for each task within the UI, aiding in debugging and validating the flow execution.
Prefect ensures that the experience of developing locally and viewing flows in the UI is closely aligned with how workflows are executed in production, thereby streamlining the management and monitoring processes.
To access more advanced visualization customizations, you might consider integrating Prefect with other visualization tools, building your own UI components on top of Prefect’s API, or contributing to Prefect’s UI if your visualization needs go beyond the existing functionalities.
For instructions and guides on the Prefect UI and server setup, consult the official Prefect documentation on hosting a server.Arun Prasad
02/14/2024, 10:17 PMArun Prasad
02/14/2024, 10:21 PMMarvin
02/14/2024, 10:23 PMshell
helm repo add prefect <https://prefecthq.github.io/prefect-helm>
helm repo update
2. Create a Namespace:
shell
kubectl create namespace prefect
3. Kubernetes Secret for API Key:
If you are using Prefect Cloud as part of your self-hosted solution for additional features, you would create a Kubernetes secret with your Prefect Cloud API key:
shell
kubectl create secret generic prefect-api-key --namespace=prefect --from-literal=key=YOUR-PREFECT-CLOUD-API-KEY
4. Configure Chart Values:
Customize the deployment by creating a values.yaml
file where you can specify configurations for the Prefect agent, UI, and other components as needed.
5. Deploy the Helm Chart:
Use the Helm command to deploy Prefect into your Kubernetes cluster using the values from your `values.yaml`:
shell
helm install prefect prefect/prefect --namespace=prefect -f values.yaml
If you're not using Prefect Cloud and are completely self-hosting, you can ignore steps that involve the Prefect Cloud API key, and focus on setting up the necessary components for your Prefect installation on Kubernetes.
For detailed information on the Helm chart and deployment processes, please refer to the official Prefect documentation on deployment with Kubernetes.Arun Prasad
02/15/2024, 1:21 AMMarvin
02/15/2024, 1:21 AMArun Prasad
02/15/2024, 1:49 AMMarvin
02/15/2024, 1:49 AMArun Prasad
02/15/2024, 1:51 AMMarvin
02/15/2024, 1:51 AMFlow
and Task
. Once defined, you can register the flow with Prefect using the CLI:
python
from prefect import flow
@flow
def my_flow():
# Define flow's tasks and logic here
# Register the flow
my_flow.register(project_name="my_project")
Creating Deployments:
Deployments are specifications for running flows. After defining a flow, you can use the Prefect CLI to create a deployment YAML file:
shell
prefect deployment build my_flow.py:my_flow -n my-deployment -q my-queue -a
This will generate a descriptive YAML file for the deployment. You can then apply this YAML file to create or update the deployment:
shell
prefect deployment apply my-deployment.yaml
Using the API:
To use the API for these operations, you would need to make HTTP POST requests to the corresponding Prefect API endpoints while including necessary details such as flow definitions in JSON format. The Prefect client libraries abstract much of the complexity involved in these API interactions.
For the exact API endpoints, request formats, and more detailed examples, please refer to Prefect’s API documentation and the GitHub repository which may include examples and further instructions on creating and managing flows and deployments via the API.Arun Prasad
02/15/2024, 5:53 PMMarvin
02/15/2024, 5:53 PMArun Prasad
02/15/2024, 8:37 PMMarvin
02/15/2024, 8:37 PMArun Prasad
02/19/2024, 10:08 PMMarvin
02/19/2024, 10:08 PMArun Prasad
02/19/2024, 10:11 PMMarvin
02/19/2024, 10:11 PMArun Prasad
02/20/2024, 12:11 AMMarvin
02/20/2024, 12:11 AMprefect deploy
command to deploy flows. As part of the deployment process, the command can also build and push Docker images if necessary.
- Multiple Deployments: You can define multiple deployment declarations within a single YAML file, each with a unique name
field. These can be deployed individually by using the --name
flag with the prefect deploy
command.
For example, a simple prefect.yaml
might look like this:
yaml
# prefect.yaml
deployment-1:
name: my-first-deployment
flow_location: flows/hello.py
work_queue_name: primary-queue
deployment-2:
name: my-second-deployment
flow_location: flows/goodbye.py
work_queue_name: secondary-queue
You can deploy a specific deployment by running a command like:
shell
prefect deploy --name my-first-deployment
For detailed information on creating flows and deployments with declarative syntax, refer to the Prefect documentation on Kubernetes integration and deployment, where you can find guidelines and examples of YAML configurations for Prefect deployments.Arun Prasad
02/20/2024, 12:15 AMMarvin
02/20/2024, 12:16 AMprefect.yaml
files and triggers corresponding actions.
2. Flow Registration:
- When developers push updates to their flow definitions, the CI/CD pipeline uses Prefect's CLI to register the flow with the central Prefect server.
- This could involve pulling the latest code from the repository, packaging it up, building a Docker image if applicable, and using the Prefect CLI or API to register the flow.
3. YAML Deployment Files:
- Developers create or update prefect.yaml
configuration files in their repositories stipulating how and where the flows should be deployed.
- The deployment.yaml
can declare multiple deployments, each with its own configurations, and developers can trigger deployments individually or altogether using the CI/CD pipeline.
4. CI/CD with Prefect Guide:
- Precise steps can be learned from Prefect's guidance on integrating with CI/CD processes. This guide provides a general template for using CI/CD to manage Prefect deployments and is adaptable to accommodate the specifics of a multi-repo setup.
5. Triggering Deployments:
- The CI/CD pipeline uses Prefect's deployment features (like the prefect deploy
command) to send these prefect.yaml
declarations to the Prefect server for deployment.
- A common pattern is to trigger this process upon merging a pull request into the main
branch, ensuring that only tested and reviewed code is deployed.
Using the concepts from Prefect’s deployment features with CI/CD provides an efficient method for managing updates to flows, changes in schedules, and container builds. This works well in a multi-repo setup by allowing individual teams to manage their deployments independently while everything converges on the central server for execution.
For more detailed instructions on setting up CI/CD with Prefect, refer to the Prefect CI/CD guide and read about the latest features such as deploying many flows at once from the Prefect release notes.Arun Prasad
02/21/2024, 6:14 AMMarvin
02/21/2024, 6:15 AM