How do I deploy a function in python with its dependencies?

Question

I'm trying to use the serverless framework to create and deploy an AWS Lambda function. I created a folder named vendored in the root of the project and installed (using pip install) the function dependencies. However, whenever I try to run it (using serverless function run) I got an error:

Serverless: Running isNewUser...
Serverless: WARNING: This variable is not defined: region
Serverless: -----------------
Serverless: Failed - This Error Was Returned:
Serverless: {"exception": ["Traceback (most recent call last):\n", " File \"/home/fernando/.nvm/versions/node/v5.10.1/bin/serverless-run-python-handler\", line 170, in \n handler = import_program_as_module(path)\n", " File \"/home/fernando/.nvm/versions/node/v5.10.1/bin/serverless-run-python-handler\", line 149, in import_program_as_module\n module = make_module_from_file('lambda_handler', handler_file)\n", " File \"/home/fernando/.nvm/versions/node/v5.10.1/bin/serverless-run-python-handler\", line 129, in make_module_from_file\n py_source_description\n", " File \"/home/fernando/workspace/os-cac/isNewUser/handler.py\", line 11, in \n from vtex.order import Order\n", "ImportError: No module named vtex.order\n"], "success": false} Serverless: Exception message from Python
Serverless: Traceback (most recent call last): , File "/home/fernando/.nvm/versions/node/v5.10.1/bin/serverless-run-python-handler", line 170, in handler = import_program_as_module(path) , File "/home/fernando/.nvm/versions/node/v5.10.1/bin/serverless-run-python-handler", line 149, in import_program_as_module module = make_module_from_file('lambda_handler', handler_file) , File "/home/fernando/.nvm/versions/node/v5.10.1/bin/serverless-run-python-handler", line 129, in make_module_from_file py_source_description , File "/home/fernando/workspace/os-cac/isNewUser/handler.py", line 11, in from vtex.order import Order ,ImportError: No module named vtex.order `

vtex.order is a module imported in handler.py

The structure of my project is something like:

/root/
     |
     |--_meta/
     |--vendored/
                |--dependencies...
     |--function-name/
                     |--handler.py
                     |--event.json
                     |--s-function.json
     |--requirements.txt
     |--admin.env
     |--package.json
     |--s-project.json
     |--s-resources-cf.json
     |--s-project.json

Is there anything I'm doing wrong? Should I somehow configure my function to include the dependencies from vendored?

Answer 1

Here are a few steps that should make it work:

1. Make sure that the handler entry in s-function.json has the function-name in its path: "handler": "function-name/handler.handler",

2. in handler.py add the following:

   import os
   import sys
   
   here = os.path.dirname(os.path.realpath(__file__))
   sys.path.append(os.path.join(here, "../vendored"))
   
   from vtex.order import Order
   

That's it. Let me know if it worked.

Answer 2

I'd recommend using the serverless-python-requirements plugin to include packages installed via pip

Answer 3

I followed below steps to deploy with dependencies:

• Created a directory for dependencies in project root mkdir .vendor

• Add dependencies in requirements.txt file manually or use pip freeze > requirements.txt

• Update serverless.yml file

package: include: - .vendor/**

• Include .vendor directory to system path in handler.py file

import sys sys.path.insert(0, './.vendor')

• Install dependencies pip install -r requirements.txt -t .vendor

Now serverless deploy will upload function with dependencies.