4.1.1 - No module named 'Image'

[cql...@gmail.com]

Hey all,
I've recently begun the process of migrating my existing weewx install to my

kubernetes cluster, using this base docker image

I'm still getting used to the setup, but it seems to be pulling data from my
weather station and populating my sqlite db. However, I'm running into problems
generating images due to a ModuleNotFoundError. Below, take a look at some of
the results of my troubleshooting.

• Here's my setup:

root@weewx-84bfc8b796-gwrr7:/home/weewx# python --version
Python 3.9.0
root@weewx-84bfc8b796-gwrr7:/home/weewx# pip --version
pip 20.2.3 from /opt/venv/lib/python3.9/site-packages/pip (python 3.9)
root@weewx-84bfc8b796-gwrr7:/home/weewx# cat version.txt
__version__ = "4.1.1"

• Here's my weewx logs showing the ModuleNotFoundError
• I found a previous thread discussing this issue, but it didn't seem to describe successful workarounds.
  
  • Here's the output from working through that thread
• Looking at this issue outside the context of weewx, it seemed reasonable to try to install pillow via pip, but doing so resulted in this long, ugly error
  

Wondering if anybody has navigated this issue before. Thanks!

[gjr80]

Appreciate you have installed PIL under python3 but are you sure that WeeWX is being run under python3 and not python2? I see nothing in what you have posted that confirms this one way or another. The python version is logged when starting WeeWX. What does the log say when you start WeeWX?

Gary

[cql...@gmail.com]

Good point. Here are the startup logs - looks like it is running the python version I was expecting: 3.9.0. (Makes sense since the base docker image is a python 3 base image)

[cql...@gmail.com]

After spending time in the Pillow github issues, I ended up getting this working by installing several packages:

RUN apt-get install zlib1g-dev libjpeg-dev build-essential -y
RUN python -m pip install Pillow

This allows me to install pillow, have it recognized by python, and therefore build my belchertown frontend!

[vince]

Your underlying issue is that you used a k8s image based on alpine and python3-slim, so it's minimal and doesn't have the build requirements for doing the pip install of Pillow.   That should be somewhat expected.   Unfortunately that's part and parcel of running minimal docker images.  I suspect you might have gotten there a little easier if you just ran a Debian-based base image (since there is already a package for PIL/Pillow you could simply add), but I suspect it would be a much larger Docker image result for your cluster.

Unrelated question - what are you doing in k8s for persistent storage of your archive and public_html trees, as well as for logging ?

[cql...@gmail.com]

You're absolutely right - and this is the consequence of building off of someone else's docker image! Had I started the process from scratch, I probably would have started with a more fully featured base image.

As for your question, I've set up an nfs share mounted to all 3 pi's, and created a persistent volume for my archive and frontend. While I haven't yet persisted my logs, that's probably a good idea, and wouldn't be too hard. I've only had the cluster up and running for a couple weeks now, so I'm definitely still learning a lot.

[vince]

On Monday, January 18, 2021 at 7:17:27 PM UTC-8 cql...@gmail.com wrote:

As for your question, I've set up an nfs share mounted to all 3 pi's, and created a persistent volume for my archive and frontend. While I haven't yet persisted my logs, that's probably a good idea, and wouldn't be too hard. I've only had the cluster up and running for a couple weeks now, so I'm definitely still learning a lot.

That's what's always stopped me here.  The cost/pain to have a quality NFS server exceeds the benefit of running kubernetes for me.

Although my quad 4GB pi4 cluster sure runs k3s nicely to say the least :-)