Serverless-python-requirements: Functions without requirements fail to package

[xedef]

I have a service with several Python functions in it. Only a couple of them need extra Python packages, so I added a requirements.txt file only for those and set the module for each function.

The problem seems to be that the plugin always expects a requirements file to install for all Python functions so for those that don't have one, it fails with this error:

  Error --------------------------------------------------

  ENOENT: no such file or directory, open 'requirements.txt'

     For debugging logs, run again after setting the "SLS_DEBUG=*" environment variable.

  Stack Trace --------------------------------------------

Error: ENOENT: no such file or directory, open 'requirements.txt'
    at Object.fs.openSync (fs.js:653:18)
    at Object.fs.readFileSync (fs.js:554:33)
    at generateRequirementsFile (/Users/fede/sls-lambda-project/node_modules/serverless-python-requirements/lib/pip.js:175:6)
    at installRequirements (/Users/fede/sls-lambda-project/node_modules/serverless-python-requirements/lib/pip.js:41:5)
    at values.filter.map.f (/Users/fede/sls-lambda-project/node_modules/serverless-python-requirements/lib/pip.js:235:11)
    at Array.map (<anonymous>)
    at ServerlessPythonRequirements.installAllRequirements (/Users/fede/sls-lambda-project/node_modules/serverless-python-requirements/lib/pip.js:222:8)
From previous event:
    at PluginManager.invoke (/Users/fede/.nvm/versions/node/v8.5.0/lib/node_modules/serverless/lib/classes/PluginManager.js:372:22)
    at PluginManager.run (/Users/fede/.nvm/versions/node/v8.5.0/lib/node_modules/serverless/lib/classes/PluginManager.js:403:17)
    at variables.populateService.then (/Users/fede/.nvm/versions/node/v8.5.0/lib/node_modules/serverless/lib/Serverless.js:102:33)
    at runCallback (timers.js:781:20)
    at tryOnImmediate (timers.js:743:5)
    at processImmediate [as _immediateCallback] (timers.js:714:5)
From previous event:
    at Serverless.run (/Users/fede/.nvm/versions/node/v8.5.0/lib/node_modules/serverless/lib/Serverless.js:89:74)
    at serverless.init.then (/Users/fede/.nvm/versions/node/v8.5.0/lib/node_modules/serverless/bin/serverless:42:50)
    at <anonymous>

Is there a way to omit certain functions? Or am I missing something?

Thanks!

[dschep]

mind sharing your serverless.yml? If I understand the issue it is a bug, the default packaging (not per function) skips with out errors(or at least used to) if no requirements files were found. Per function packaging should do the same. I'll see if I can create some test cases to covers these.

[xedef]

Hi. I think the key part from your answer is "not per function".

I've just tested this yml:

service: requirements-test

provider:
  name: aws
  runtime: python3.6

package:
  individually: true
  exclude:
    - "**/*"

functions:
  func1:
    handler: func1/index.handler
    module: func1
    include:
      - function1/index.py
  func2:
    handler: func2/index.handler
    include:
      - function2/index.py

plugins:
  - serverless-python-requirements

custom:
  pythonRequirements:
    invalidateCaches: true
    dockerizePip: false

If you create those two functions and don't add a requirements.txt at root level and just only one for func1, when you run sls package, the plugin runs correctly for func1 but for func2 gives that error.

λ ~/tmp/requirements-test/ sls package
Serverless: Installing requirements of func1/requirements.txt in .serverless/func1...

  Error --------------------------------------------------

  ENOENT: no such file or directory, open 'requirements.txt'

     For debugging logs, run again after setting the "SLS_DEBUG=*" environment variable.

  Get Support --------------------------------------------
     Docs:          docs.serverless.com
     Bugs:          github.com/serverless/serverless/issues
     Issues:        forum.serverless.com

  Your Environment Information -----------------------------
     OS:                     darwin
     Node Version:           8.5.0
     Serverless Version:     1.27.3

For the moment, I cant get rid of the error just by adding an empty requirements.txt at root level.

[dschep]

Thanks for the details. That's a :bug:

For now I recommend the workaround you mention of an empty requirements.txt, but I'll fix this in the next release.