Hi all I have some odd behavior happening for a flow deploye

Question

Hi all I have some odd behavior happening for a flow deployed to prefect cloud This might be hard to explain but I will put most of the details in a thread

Leon Kozlowski · Answer

Agent Kubernetes Storage Docker

Leon Kozlowski · Answer

I use a jenkins pipeline to build and register my flows This jenkins pipeline creates tmp directories to build and install dependencies in order to execute `prefect build ` and `prefect register ` My Dockerfiles are configured to use a `WORKDIR` called ` app`

Leon Kozlowski · Answer

Typically in flow logs for failures I m able to see a traceback and see ```File app src lt some file gt py line 28 lt function name gt ``` etc

Leon Kozlowski · Answer

The most recent flow I deployed I am seeing tracebacks that are calling functions from `tmp` directories that my Jenkinsfile creates which is causing flows to fail while loading environment variables since my environment variables exist in cluster through k8s secrets

Leon Kozlowski · Answer

An example traceback blanked out function file names ```Task XXXXX Exception encountered during task execution Traceback most recent call last File usr local lib python3 8 site packages prefect engine task runner py line 876 in get task run state value = prefect utilities executors run task with timeout File usr local lib python3 8 site packages prefect utilities executors py line 467 in run task with timeout return task run args kwargs type ignore File tmp jenkins XXXXXX workspace XXXXX prefect flows flows XXXXX src tasks XXXXX py line 32 in XXXXX File app src helpers py line 28 in query db engine = create engine url=url File lt string gt line 2 in create engine``` I tried rebuilding my flow with no cache but I m still seeing this odd jenkins tmp filepath being called for task runs

Anna Geller · Answer

could this import error be because the WORKDIR is not ` app src` looks like your flow is looking for this one rather than app re environment variables this is a common and understandable source of issues with respect to build time vs runtime that Prefect 2 0 tries to address you need to make sure that if you use those env variables somewhere in your flow code then they must also exist in your build environment Jenkins server not only in your execution layer Kubernetes

Leon Kozlowski · Answer

I copy `src` into my `WORKDIR`

Anna Geller · Answer

I see still somehow copying files over doesn t seem to add them to the PYTHONPATH to make those importable in your flow code Have you thought about building a package to make that easier

Anna Geller · Answer

it could be something as simple as then copy and install as

Leon Kozlowski · Answer

hmm I m just sort of confused because I havent experienced this with any of my other flows

Leon Kozlowski · Answer

I am setting a pythonpath in my dockerfile ```ENV PYTHONPATH= $PYTHONPATH src COPY from=builder usr local lib python3 8 site packages usr local lib python3 8 site packages WORKDIR app COPY src src COPY job template yaml COPY VERSION ```

Anna Geller · Answer

I can understand that Python path is peculiar smile

Leon Kozlowski · Answer

So I actually just got it to work

Leon Kozlowski · Answer

And this might sound insane but 1 of my tasks was a function with a decorator

Anna Geller · Answer

wow what did you do differently

Leon Kozlowski · Answer

and I changed that to a subclass of `Task` and it worked

Anna Geller · Answer

generally ` task` is preferred over `Task` but if it works slightly smiling face

Leon Kozlowski · Answer

What do you mean

Anna Geller · Answer

it would be good to understand why this change helped