poc-prefect-containerized

Proof of concept for simple containerized flows with prefect in a local environment. The repo structure can be used as a template and the example folder removed respectively.

Pre-Requisites

• Docker installed, if run with cuda -> nvidia-docker installed
• Each flow repository consists of a working Dockerfile
• Flow tested locally and it is running

Build steps

Use this repo structure as template and copy your data flow repository inside this structure.

1. Clone Repos with prefect flows inside root
2. Build Images from Repo Dockerfiles
   • Make sure naming of images is equal to image names in docker-compose.yaml
3. Run Images in container and build prefect deployments
4. Start prefect orion UI
5. Start docker compose cli and apply prefect deployments
6. Start agents

1. Clone flows and applications

git clone <dataflow-repo>
git clone <another-dataflow-repo>

2. Build Flow Images from Dockerfiles

Build images from Dockerfiles for each repo or application containing a prefect flow. The Dockerfile need prefect as base image or as pip installation in the requirements.

docker build . -f <your-Dockerfile> --tag custom-worker-image

Remark: Make sure that the named tag corresponds with the ones given in the docker-compose.yaml for each agent.

3. Build Prefect deployments

Now, the prefect deployments will be made within each container as the correct dependencies for the prefect builds are available.

docker run -it -v $PWD:/root/ <your-flow-image>

within the flow-container

prefect deployment build <script-name>:<flow-function> -n <deployment-name> -q <working-queue-name>

Remark: The working queue names need to be consistent with the queue names in the docker-compose.yaml

4. Start orion UI with

docker compose --profile orion up

The Orion UI should no be accessible witin your localhost 127.0.0.1:4200

5. Run compose cli and apply builds

docker compose run cli

then, apply the created deployment yaml

prefect deployment apply <flow-function>-deployment.yaml

Check the if the deployments are available in the orion UI under deployments. If they are, everything worked fine.

6. Start Agents

docker compose --profile <agent> up

Check the working queues in the Orion UI. If the queues are marked as Healthy, than the agents are listening to the UI.

Sources

https://github.com/rpeden/prefect-docker-compose

rpeden/prefect-docker-compose#1

https://docs.prefect.io/