Fixes weird bug, where root & submodule requirements weren't packaged correctly

[bweigel]

What it does?

This PR fixes a weird bug, that wouldn't let you use a top-level requirements.txt alongside sub-module requirement.txt-files.

Problem

The previous (I guess) unwanted behavior was, that when you had a root level function (i.e. module: .) with a requirements.txt and a second (sub-module) function (i.e. module: my_submodule) the first function didn't receive any requirements at all, whereas all requirements (from root and submodule) ended up in the artifact for function two:

see sample code: https://github.com/bweigel/serverless_playground/tree/293_weird_bug/sls_package

serverless.yml:

service: packaging_test

plugins:
  - serverless-python-requirements

provider:
  name: aws
  runtime: python3.6
  region: eu-central-1

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

functions:
  function-one:
    handler: main.handler
    package:
      include:
        - 'main.py'

  function-two:
    handler: main.handler
    module: fn
    package:
      include:
        - 'fn/**'

$ sls package

The top-level requirements are not packaged for function-one:

$ zipinfo .serverless/function-one.zip
Archive:  .serverless/function-one.zip
Zip file size: 251 bytes, number of entries: 1
-rw-rw-r--  3.0 unx      260 b- defN 80-Jan-01 00:00 main.py
1 file, 260 bytes uncompressed, 139 bytes compressed:  46.5%

but are instead included in function-two (where they don't belong):

 $ zipinfo .serverless/fn-packaging_test-dev-function-two.zip
Archive:  .serverless/fn-packaging_test-dev-function-two.zip
Zip file size: 116671 bytes, number of entries: 52
-rw-rw-r--  3.0 unx        0 b- stor 98-Jan-01 00:00 __init__.py
drwxrwxr-x  3.0 unx        0 b- stor 19-Jan-04 14:40 __pycache__/
-rw-rw-r--  3.0 unx      148 b- defN 98-Jan-01 00:00 __pycache__/__init__.cpython-36.pyc
-rw-rw-r--  3.0 unx      290 b- defN 98-Jan-01 00:00 __pycache__/other_module.cpython-36.pyc
-rw-rw-r--  3.0 unx      237 b- defN 98-Jan-01 00:00 __pycache__/yam.cpython-36.pyc
-rw-rw-r--  3.0 unx      260 b- defN 98-Jan-01 00:00 main.py
-rw-rw-r--  3.0 unx       61 b- defN 98-Jan-01 00:00 other_module.py
-rw-rw-r--  3.0 unx        8 b- defN 98-Jan-01 00:00 requirements.txt
-rw-rw-r--  3.0 unx    45208 b- defN 98-Jan-01 00:00 dataclasses.py
drwxrwxr-x  3.0 unx        0 b- stor 19-Jan-04 14:40 urllib3/
-rw-rw-r--  3.0 unx    13839 b- defN 98-Jan-01 00:00 urllib3/connection.py
-rw-rw-r--  3.0 unx     2722 b- defN 98-Jan-01 00:00 urllib3/__init__.py
-rw-rw-r--  3.0 unx    10746 b- defN 98-Jan-01 00:00 urllib3/_collections.py
drwxrwxr-x  3.0 unx        0 b- stor 19-Jan-04 14:40 urllib3/contrib/
-rw-rw-r--  3.0 unx        0 b- stor 98-Jan-01 00:00 urllib3/contrib/__init__.py
drwxrwxr-x  3.0 unx        0 b- stor 19-Jan-04 14:40 urllib3/contrib/_securetransport/
-rw-rw-r--  3.0 unx        0 b- stor 98-Jan-01 00:00 urllib3/contrib/_securetransport/__init__.py
-rw-rw-r--  3.0 unx      717 b- defN 98-Jan-01 00:00 urllib3/contrib/_appengine_environ.py
-rw-rw-r--  3.0 unx    35097 b- defN 98-Jan-01 00:00 urllib3/connectionpool.py
-rw-rw-r--  3.0 unx    10914 b- defN 98-Jan-01 00:00 urllib3/contrib/appengine.py
-rw-rw-r--  3.0 unx    17560 b- defN 98-Jan-01 00:00 urllib3/contrib/_securetransport/bindings.py
-rw-rw-r--  3.0 unx    12162 b- defN 98-Jan-01 00:00 urllib3/contrib/_securetransport/low_level.py
-rw-rw-r--  3.0 unx     4459 b- defN 98-Jan-01 00:00 urllib3/contrib/ntlmpool.py
-rw-rw-r--  3.0 unx    15806 b- defN 98-Jan-01 00:00 urllib3/contrib/pyopenssl.py
-rw-rw-r--  3.0 unx     6391 b- defN 98-Jan-01 00:00 urllib3/contrib/socks.py
-rw-rw-r--  3.0 unx     6604 b- defN 98-Jan-01 00:00 urllib3/exceptions.py
-rw-rw-r--  3.0 unx     5943 b- defN 98-Jan-01 00:00 urllib3/fields.py
-rw-rw-r--  3.0 unx    30309 b- defN 98-Jan-01 00:00 urllib3/contrib/securetransport.py
-rw-rw-r--  3.0 unx     2436 b- defN 98-Jan-01 00:00 urllib3/filepost.py
drwxrwxr-x  3.0 unx        0 b- stor 19-Jan-04 14:40 urllib3/packages/
-rw-rw-r--  3.0 unx      109 b- defN 98-Jan-01 00:00 urllib3/packages/__init__.py
drwxrwxr-x  3.0 unx        0 b- stor 19-Jan-04 14:40 urllib3/packages/backports/
-rw-rw-r--  3.0 unx        0 b- stor 98-Jan-01 00:00 urllib3/packages/backports/__init__.py
-rw-rw-r--  3.0 unx    30098 b- defN 98-Jan-01 00:00 urllib3/packages/six.py
-rw-rw-r--  3.0 unx     1456 b- defN 98-Jan-01 00:00 urllib3/packages/backports/makefile.py
drwxrwxr-x  3.0 unx        0 b- stor 19-Jan-04 14:40 urllib3/packages/ssl_match_hostname/
-rw-rw-r--  3.0 unx      688 b- defN 98-Jan-01 00:00 urllib3/packages/ssl_match_hostname/__init__.py
-rw-rw-r--  3.0 unx     5683 b- defN 98-Jan-01 00:00 urllib3/packages/ssl_match_hostname/_implementation.py
-rw-rw-r--  3.0 unx    16853 b- defN 98-Jan-01 00:00 urllib3/poolmanager.py
drwxrwxr-x  3.0 unx        0 b- stor 19-Jan-04 14:40 urllib3/util/
-rw-rw-r--  3.0 unx     4639 b- defN 98-Jan-01 00:00 urllib3/util/connection.py
-rw-rw-r--  3.0 unx      497 b- defN 98-Jan-01 00:00 urllib3/util/queue.py
-rw-rw-r--  3.0 unx    25609 b- defN 98-Jan-01 00:00 urllib3/response.py
-rw-rw-r--  3.0 unx     3705 b- defN 98-Jan-01 00:00 urllib3/util/request.py
-rw-rw-r--  3.0 unx     2586 b- defN 98-Jan-01 00:00 urllib3/util/response.py
-rw-rw-r--  3.0 unx    15105 b- defN 98-Jan-01 00:00 urllib3/util/retry.py
-rw-rw-r--  3.0 unx    13143 b- defN 98-Jan-01 00:00 urllib3/util/ssl_.py
-rw-rw-r--  3.0 unx     9757 b- defN 98-Jan-01 00:00 urllib3/util/timeout.py
-rw-rw-r--  3.0 unx     6487 b- defN 98-Jan-01 00:00 urllib3/util/url.py
-rw-rw-r--  3.0 unx     5403 b- defN 98-Jan-01 00:00 urllib3/util/wait.py
-rw-rw-r--  3.0 unx     1044 b- defN 98-Jan-01 00:00 urllib3/util/__init__.py
-rw-rw-r--  3.0 unx     5991 b- defN 98-Jan-01 00:00 urllib3/request.py
52 files, 370770 bytes uncompressed, 110057 bytes compressed:  70.3%

Relates to

• General requirements.txt while using Per-function requirements #174

[dschep]

Thanks @bweigel, this PR looks great. Love the attention to detail!

I'll merge it after tests pass.