Deploy GCP Cloud function with local dependencies

Question

I have been trying to deploy a Cloud Function with some private dependencies ( pyodbc ) as I couldn't get it working thru requirements.txt . Please note, I don't want to use Docker here. So all I have built here is below files,

1. main.py
2. process.py ( this one use pyodbc to connect to teradata)
3. libs (folder)
   3.1 pyodbc-4.0.30.dist-info (package)
   3.2 pyodbc (python extension module)
   3.3 __init.py__ ( this is to make this folder as module)
4.requirements.txt

I also updated process.py file to import pyodbc module as below,

import libs.pyodbc

Please note: I used GCP docs to install the pyodbc package and put in libs using https://cloud.google.com/functions/docs/writing/specifying-dependencies-python On top this, I am also requirements.txt to import as default.

But I am still getting module error as below.

Error message: Code in file main.py can't be loaded.
Did you list all required modules in requirements.txt?
Detailed stack trace: Traceback (most recent call last):
  File "/env/local/lib/python3.7/site-packages/google/cloud/functions/worker.py", line 305, in check_or_load_user_function
    _function_handler.load_user_function()
  File "/env/local/lib/python3.7/site-packages/google/cloud/functions/worker.py", line 184, in load_user_function
    spec.loader.exec_module(main)
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/user_code/main.py", line 9, in <module>
    from process import process
  File "/user_code/process.py", line 6, in <module>
    import libs.pyodbc
ModuleNotFoundError: No module named 'libs.pyodbc'

Any leads or help from here is really appreciated. All I am trying to achieve here is, Read CSV files from GCP bucket and process it thru dataframe which loads into teradata and generate output file back into another GCP bucket. I am trying to achieve all with Cloud Functions only. Thank you

Answer 1

The pyodbc project might be a bit of a special case here, because:

1. The project requires some platform-specific code;
2. They haven't published source distributions for their latest release (only built distributions).

Here's what I did to get this to work. Starting with an empty libs directory, first download the latest available source distribution:

$ pip download pyodbc --no-binary :all:

Make a directory for the module:

$ mkdir libs/pyodbc

Untar the source distribution into the module:

$ tar xf pyodbc-4.0.28.tar.gz -C libs/pyodbc

Then, in the function you can do:

import libs.pyodbc