serverless-custom-packaging-plugin

What is this plugins purpose?

This plugin was originally built to allow deployment of arbitrarily nested python lambdas using serverless. The functionality is related to the one discussed in this serverless issue (#3366).

The Problem

Vanilla serverless packages your source-code, but retains the folder structure inside the zip-file. However, AWS Lambda can only find the entry-point to your function if it is packaged in a zip-files at root level (see the AWS-Lambda docs).

How it was solved

You define a path that you want to package inside of serverless's package property. The plugin then packages your code, such that te defined path becomes the root-path (.) of the package zip-file.

What else it can do

1. Custom artifact path. You can define an artifact property. The zip-file will be placed there.
2. If you want to include only certain file-names or extensions you may define them using the include_globs property.
3. If you have additional libraries you need inside the lambda environment you may define a path in the libs property. The contents of this folder will be packaged alongside your functions code (in the root of the zip-file). This lets you include arbitrary python modules (i.e. built against the Lambda AMI inside of docker), but keep them away from your code during development.

Installation

npm install serverless-custom-packaging-plugin --save-dev

This installs the plugin into your node_modules and adds the dev-dependency to your package.json.

How to use it

plugins:
  - serverless-custom-packaging-plugin
...
functions:
  myFunction:
    ...
    package:
      path: path/to/my/code
      artifact: path/to/my/artifact.zip
      libs: path/to/libs 
      include_globs:
        - "**/*.py"
        - "**/*.json"

Tested with ...

Serverless version	serverless deploy	serverless package -f <function-name>	serverless deploy function -f <function_name>	comment
1.10.0
1.11.0				not tested
1.12.0				not tested
1.13.0				not tested
1.14.0
1.15.0
1.16.0
1.17.0			/	everything works when patched
1.18.0				package.individually = true must be set

Patches

We have created a couple of patches (so far only for serverless version 1.17.0) to get all the functionality we needed working. You are free to use these patches, but be aware that this could potentially break (other) serverless functionality.

A word of caution

This is a work in progress. This means no guarantees that everything will work as promised. If you would like some more functionality you are welcome to contribute. We greatly appreciate any testing you do with different serverless versions and setups.