When I use a prefect worker (GCP Cloud Run V2 worker to be precise), I deploy using the official prefect docker image, which is pinned to a version. However, when the

--install-policy

is set to

always

the worker will install the latest version of prefect + dependencies when starting up, which circumvents the pinned version. When I instead change the

--install-policy

to

if-not-present

, it's able to install the

prefect[gcp]

dependencies fine but I keep getting the error

Unable to start worker. Please ensure you have the necessary dependencies installed to run your desired worker type.

after the dependencies have installed correctly:

"Successfully installed google-api-core-2.22.0 google-api-python-client-2.151.0 google-auth-2.35.0 google-auth-httplib2-0.2.0 google-cloud-core-2.4.1 google-cloud-secret-manager-2.21.0 google-cloud-storage-2.18.2 google-crc32c-1.6.0 google-resumable-media-2.7.2 googleapis-common-protos-1.65.0 grpc-google-iam-v1-0.13.1 grpcio-1.67.1 grpcio-status-1.67.1 httplib2-0.22.0 prefect-gcp-0.6.1 proto-plus-1.25.0 protobuf-5.28.3 pyasn1-0.6.1 pyasn1-modules-0.4.1 pyparsing-3.2.0 rsa-4.9 tenacity-9.0.0 uritemplate-4.1.1"

Kinda hard to ascertain what the issue is here, anyone else seen this? I'm deploying the worker via Terraform, with the following

args

list:

args = [
        "prefect",
        "worker",
        "start",
        "--install-policy", "if-not-present",
        "--with-healthcheck",
        "-p", <my-workpool-name>,
        "-t", "cloud-run-v2"
      ]

I am having this issue as well. Unable to resolve

Hey @Daniel, nah didn't find a good resolution yet, just had to upgrade to the latest Prefect version and redeploy. Would like to understand what the actual issue is and get a proper solution but haven't had a chance to log an issue yet.

I seem to have figured out a fix finally. Seems to work for me when the dockerfile that runs the command to start the work pool is setup like this:

# Use Python slim as the base image
FROM python:3.10-slim

# Set the working directory in the container
WORKDIR /app

# Install required system dependencies
RUN apt-get update --allow-releaseinfo-change && \
    apt-get install -y --no-install-recommends \
    curl \
    gcc \
    libffi-dev \
    libssl-dev \
    && rm -rf /var/lib/apt/lists/*

# Install Prefect v2.19.9 and dependencies
RUN pip install --no-cache-dir prefect==2.19.9
RUN pip install prefect-docker
RUN pip install prefect-gcp

I think my issue was that I wasn’t explicitly installing prefect-docker

Yeah building your own image like this will ofc fix the issue, but shouldn't be necessary IMO.

Yeah true