<@ULVA73B9P> is there a way to run flows on Prefec...
# ask-marvin
a
@Marvin is there a way to run flows on Prefect Cloud from a Github repo that has a monorepo structure (the package path is not the root of the repository)?
m
thought for 177.9 seconds
Yes — Prefect 3.x works well with monorepos. You have two common options: Option A: Deploy via Python with flow.from_source(...).deploy(...) - Point to your GitHub repo and give an entrypoint that’s relative to the repo root. - For monorepos, just include the subdirectory in the entrypoint. You can also use sparse checkout to pull only the needed subdir. Example:
Copy code
from prefect import flow
from prefect.runner.storage import GitRepository
from prefect.blocks.system import Secret

# Optional: for private repos or sparse checkout
storage = GitRepository(
    url="<https://github.com/org/my-repo.git>",
    # directories limits clone to subdirs (good for monorepos)
    directories=["services/data-pipeline"],
    credentials={"access_token": Secret.load("github-token")},
    branch="main",
)

flow.from_source(
    source=storage,  # or just "<https://github.com/org/my-repo.git>" for public repos
    entrypoint="services/data-pipeline/flows/etl.py:etl_flow",  # path is from repo root
).deploy(
    name="data-pipeline-etl",
    work_pool_name="my-work-pool",
)
Option B: Use a prefect.yaml with pull steps - Use the git_clone step (supports sparse checkout via directories). - Then set the working directory to the subfolder that contains your flows. - Entrypoint becomes relative to that working directory. Example prefect.yaml:
Copy code
prefect-version: "3.x"
name: my-monorepo

pull:
  - prefect.deployments.steps.git_clone:
      id: clone
      repository: <https://github.com/org/my-repo.git>
      branch: main
      # Optional (recommended for monorepos): clone only what you need
      directories:
        - services/data-pipeline
      # For private repos:
      # access_token: "{{ prefect.blocks.secret.github-token }}"

  - prefect.deployments.steps.set_working_directory:
      directory: "{{ clone.directory }}/services/data-pipeline"

deployments:
  - name: data-pipeline-etl
    entrypoint: flows/etl.py:etl_flow  # now relative to the working dir above
    work_pool:
      name: my-work-pool
Then deploy:
Copy code
prefect deploy --name data-pipeline-etl
# or
prefect deploy --all
Notes and tips - Entrypoint format is file.py:function_name. With flow.from_source it’s relative to the repo root; with prefect.yaml after set_working_directory it’s relative to that directory. - For private repos, use a Secret or credentials block; avoid hardcoding tokens. - If your flow imports shared code from other monorepo packages, either: - Build an image that installs those packages, or - Set PYTHONPATH via your work pool’s job_variables env so imports resolve at runtime. Docs to learn more - Deployments overview: https://docs.prefect.io/latest/deploy/ - CLI deploy command (for prefect.yaml): https://docs.prefect.io/latest/deploy/#deploy-your-project If you can share: - The subdirectory where your flow lives - Whether you prefer Python-based or prefect.yaml-based deploys - Whether the repo is private …I can tailor an exact config for your repo.
a
i'm getting
Copy code
from google import genai
ModuleNotFoundError: No module named 'google'
although this module is in my uv project
@Marvin i'm getting
Copy code
from google import genai
ModuleNotFoundError: No module named 'google'
although this module is in my uv project
m
thought for 254.1 seconds
That error means the runtime environment your flow runs in doesn’t have the package installed. Having it in your local uv project doesn’t automatically carry over to the worker/agent environment. Quick fixes (pick one): 1) Use an image that includes the dependency (recommended for production) - If you’re using a Docker/Kubernetes work pool, build or reference an image that has google-genai installed. Example Dockerfile:
Copy code
FROM prefecthq/prefect:3.1.0-python3.12
WORKDIR /app
COPY pyproject.toml uv.lock ./
# If you’re using uv for the project:
# Install your project deps (choose the approach you use locally)
# Example with a requirements file:
# COPY requirements.txt .
# RUN uv pip install -r requirements.txt
# Or install the package itself:
# COPY . .
# RUN uv pip install .
# If you prefer standard pip, use pip install instead of uv.

# Minimal example if using requirements.txt:
# COPY requirements.txt .
# RUN uv pip install -r requirements.txt

COPY . .
Then set the deployment to use that image (via
.deploy(..., image=...)
or in
prefect.yaml
with
job_variables.image
). 2) Install dependencies on the worker host (Process/Local work pools) - If you’re running a Process worker on a VM/laptop, install into the same environment the worker uses:
Copy code
uv pip install google-genai
# or
pip install google-genai
Then restart the worker and re-run. 3) Install at runtime with a pull step (easy for dev; slower per run) - Add a
pip_install_requirements
step to your
prefect.yaml
so the worker installs deps before running the flow:
Copy code
pull:
  - prefect.deployments.steps.git_clone:
      id: clone
      repository: <https://github.com/your-org/your-repo.git>

  - prefect.deployments.steps.set_working_directory:
      directory: "{{ clone.directory }}/path/to/your/subdir"  # if using a monorepo

  - prefect.deployments.steps.pip_install_requirements:
      directory: "{{ clone.directory }}/path/to/your/subdir"
      requirements_file: requirements.txt  # ensure it lists `google-genai`
Important notes - The package name to install is likely
google-genai
(which provides
google.genai
). Make sure that’s what you’re installing; installing
google
alone won’t give you
google.genai
. - If your repo has a top-level folder named
google/
, it can shadow the namespace and cause import issues. Rename it if present. - If you’re relying on pyproject.toml/uv only (no requirements.txt), either: - Use a custom Dockerfile that runs
uv pip install .
(or
uv sync
) to install your project, or - Generate a requirements.txt (uv can export one) and use the runtime install step above. If you can share: - Your work pool type (Docker/Kubernetes/Process) - How you’re deploying (Python
.deploy
,
prefect.yaml
, or
flow.from_source
) - Whether you have a Docker image configured - Where your requirements live (pyproject/requirements.txt and path) …I can give an exact snippet tailored to your setup. Refs: - Deploy projects and manage environments: https://docs.prefect.io/latest/deploy/ - Steps (git_clone, pip_install_requirements, set_working_directory): https://docs.prefect.io/latest/deploy/#pull-steps
a
@Marvin i'm using prefect cloud and my reqs are in uv
m
thought for 65.8 seconds
Got it — since your deps are managed with uv, the runtime where your flow executes still needs those packages installed. The quickest path depends on your work pool type. First, sanity check the package name - For
from google import genai
, you need the
google-genai
package (not
google
). - Make sure your pyproject has something like:
Copy code
[project]
dependencies = [
  "google-genai>=0.3.0",
  "prefect>=3"
]
Pick one of these setups: 1) Docker/Kubernetes work pool (recommended) Bake your uv project into the image used by the deployment so the worker already has deps. Dockerfile:
Copy code
FROM prefecthq/prefect:3.1.0-python3.12
WORKDIR /app

# Copy only lock files first for better caching
COPY pyproject.toml uv.lock ./
# Create a project venv with your locked deps
RUN uv sync --frozen --no-dev
ENV VIRTUAL_ENV=/app/.venv
ENV PATH="/app/.venv/bin:${PATH}"

# Copy the rest of your code
COPY . .
Then reference this image in your deployment (Python or prefect.yaml):
Copy code
# prefect.yaml (example)
deployments:
  - name: my-deployment
    entrypoint: path/to/flow.py:my_flow
    work_pool:
      name: my-docker-pool
      job_variables:
        image: "your-registry/your-image:tag"
2) Process work pool (no containers) Run the worker from your uv virtual environment so it uses that interpreter for all flow runs:
Copy code
cd /path/to/your/project
uv sync  # creates .venv with deps from uv.lock
source .venv/bin/activate
prefect worker start -p your-work-pool
Now the worker’s Python has
google-genai
, and your flow imports will succeed. 3) Install deps at runtime (good for dev; slower) If you prefer pull steps, install into the current interpreter before the flow runs. With uv projects you can either: - Maintain a requirements.txt and use
pip_install_requirements
, or - Run uv directly via a shell step and install packages into the current interpreter. Example using uv directly:
Copy code
pull:
  - prefect.deployments.steps.git_clone:
      id: clone
      repository: <https://github.com/your-org/your-repo.git>

  - prefect.deployments.steps.set_working_directory:
      directory: "{{ clone.directory }}/path/to/subdir"

  - prefect.deployments.steps.run_shell_script:
      script: |
        # Install directly into the interpreter the worker uses
        uv pip install google-genai
        # add any other packages you need here
Note:
uv sync
creates a separate venv; unless you also switch the interpreter Prefect uses, the flow won’t see that venv. Prefer
uv pip install ...
if you go this route. Helpful refs - Deployments and environments: https://docs.prefect.io/latest/deploy/ - Pull steps (git_clone, run_shell_script, pip_install_requirements): https://docs.prefect.io/latest/deploy/#pull-steps If you tell me: - Your work pool type (Docker/Kubernetes/Process) - How you’re deploying (Python
.deploy
vs
prefect.yaml
) - Whether your project is a package (so
uv pip install .
is viable) …I can give you an exact, copy-paste config for your setup.
a
@Marvin but i wanna still use prefect cloud infra
m
thought for 159.8 seconds
Totally fine to stay on Prefect Cloud’s managed (serverless) infrastructure. Since you can’t bring a custom image there, you’ll install deps at runtime. Two easy patterns: 1) Add pip packages via job variables (fastest) - Prefect Managed pools support installing extra packages before your run. Python deploy:
Copy code
flow.from_source(
    source="<https://github.com/your-org/your-repo.git>",
    entrypoint="path/to/flow.py:my_flow",
).deploy(
    name="my-deployment",
    work_pool_name="your-managed-pool",
    job_variables={
        "pip_packages": ["google-genai"]  # provides `from google import genai`
    },
)
prefect.yaml:
Copy code
deployments:
  - name: my-deployment
    entrypoint: path/to/flow.py:my_flow
    work_pool:
      name: your-managed-pool
      job_variables:
        pip_packages:
          - google-genai
2) Use pull steps and run uv in the managed runtime (good if you want to install your project) - Prefer
uv pip install ...
(installs into the current interpreter). Avoid
uv sync
(it creates a separate venv the run won’t use). Example (monorepo-friendly):
Copy code
pull:
  - prefect.deployments.steps.git_clone:
      id: clone
      repository: <https://github.com/your-org/your-repo.git>
      # optional sparse checkout
      # directories: ["services/my-service"]

  - prefect.deployments.steps.set_working_directory:
      directory: "{{ clone.directory }}/services/my-service"  # adjust if needed

  # Install exactly what you need:
  - prefect.deployments.steps.run_shell_script:
      script: |
        # Install the package you’re missing
        uv pip install google-genai

        # If your subdir is a Python package with pyproject.toml:
        # uv pip install .
Notes - Double-check your uv deps include
google-genai
(not
google
). - If your repo has a top-level
google/
folder, it can shadow the namespace; rename it if present. If you confirm: - The pool is “Prefect Managed” (serverless) - Where your pyproject lives (path in the monorepo) …I can tailor the exact
prefect.yaml
or
.deploy()
snippet for your repo. Refs: - Deployments overview: https://docs.prefect.io/latest/deploy/ - Pull steps (git_clone, run_shell_script): https://docs.prefect.io/latest/deploy/#pull-steps
a
@Marvin and if i create a docker image, can prefect run it on its serverless infra?
m
thought for 74.4 seconds
Short answer: Not on Prefect Managed (serverless) pools. Managed pools can’t run your custom Docker image; they use Prefect’s runtime and let you add Python packages at run time (e.g., via
pip_packages
or pull steps). If you want to run your own image without hosting a worker, use a “push” work pool (still serverless, but on your cloud provider): - AWS ECS (Fargate): ecs:push - Azure Container Instances: azure-container-instance:push - Google Cloud Run: cloud-run:push - Modal / Coiled: push pools with their own packaging models How you’d reference your image in a deployment Python:
Copy code
from prefect import flow
from prefect.docker import DockerImage

@flow
def my_flow():
    ...

my_flow.deploy(
    name="genai",
    work_pool_name="my-cloud-run-pool",  # or ecs/aci/etc
    image=DockerImage(
        name="<http://gcr.io/my-proj/myimage:latest|gcr.io/my-proj/myimage:latest>",
        # Cloud Run requires amd64; specify if you built on arm:
        platform="linux/amd64",
    ),
)
prefect.yaml:
Copy code
deployments:
  - name: genai
    entrypoint: path/to/flow.py:my_flow
    work_pool:
      name: my-ecs-pool
      job_variables:
        image: "<http://123456789012.dkr.ecr.us-east-1.amazonaws.com/myimage:latest|123456789012.dkr.ecr.us-east-1.amazonaws.com/myimage:latest>"
Building your image with uv
Copy code
# Dockerfile
FROM prefecthq/prefect:3.1.0-python3.12
WORKDIR /app
COPY pyproject.toml uv.lock ./
RUN uv sync --frozen --no-dev \
 && . .venv/bin/activate \
 && python -c "import sys; print(sys.executable)"
ENV VIRTUAL_ENV=/app/.venv
ENV PATH="/app/.venv/bin:${PATH}"
COPY . .
Recap: - Prefect Managed (Prefect-hosted): no custom images; add deps via
pip_packages
or pull steps like
run_shell_script: uv pip install google-genai
. - Push pools (provider serverless): yes to custom images; ideal if you need uv-locked envs and system packages. If you tell me which provider you prefer (ECS, ACI, Cloud Run), I’ll share a minimal, copy-paste setup for the work pool and deployment. Links: - Work pools overview: https://docs.prefect.io/latest/concepts/work-pools/ - Deployments: https://docs.prefect.io/latest/deploy/