Awesome

Serverless Layers

Automatically attaches layers to the provider and for each function
- Skips functions with no other layers as they will use the layer(s) we added to the provider
Creates a new layer's version when dependencies are updated
Does not publish a new layer if dependencies are unchanged
Drastically reduces lambda size
Reduces deployment time
Allows sharing of the same layers (libraries) among all lambda functions

Common Requirements

AWS only (sorry)
Serverless >= 1.34.0 (layers support)

Install

npm install -D serverless-layers

serverless plugin install --name serverless-layers

Add the plugin to your serverless.yml file:

Single layer config

Example:

plugins:
  - serverless-layers
  
custom:
  serverless-layers:
    functions: # optional
      - my_func2
    dependenciesPath: ./package.json

functions:
  my_func1:
    handler: handler.hello
  my_func2:
    handler: handler.hello

Multiple layers config

Example:

plugins:
  - serverless-layers
  
custom:
  serverless-layers:
    # applies for all lambdas 
    - common:
        dependenciesPath: ./my-folder/package.json
    # apply for foo only
    - foo:
        functions:
          - foo
        dependenciesPath: my-folder/package-foo.json
    - staticArn:
        functions:
          - foo
          - bar
        arn: arn:aws:lambda:us-east-1:<your_account>:layer:node-v13-11-0:5

functions:
  foo:
    handler: handler.hello
  bar:
    handler: handler.hello

Screen Shot 2020-04-05 at 2 04 38 pm

Option	Type	Default	Description
compileDir	`string`	.serverless	Compilation directory
layersDeploymentBucket	`string`		Specify a bucket to upload lambda layers. `Required if deploymentBucket is not defined.`
customInstallationCommand	`string`		Specify a custom command to install dependencies, e.g., `MY_ENV=1 npm --proxy http://myproxy.com i -P`
customHash	`string`		Specify a custom string that, once changed, will force a new build of the layer
retainVersions	`int`	`null`	Number of layer versions to keep; older versions will be removed after deployments

NodeJS

Requirements

Node >= v6.10.3
NPM >= 3.10.10
A valid package.json file

Options

Option	Type	Default	Description
packageManager	`string`	npm	Possible values: npm, yarn
packagePath	`string`	package.json	`(DEPRECATED)`: Available for `<= 1.5.0`; for versions `>= 2.x`, use `compatibleRuntimes`
dependenciesPath	`string`	package.json	Note: `>= 2.x` versions. You can specify a custom path for your `package.json`
compatibleRuntimes	`array`	`['nodejs']`	Possible values: nodejs, nodejs10.x, nodejs12.x
layerOptimization.cleanupPatterns	`array`	check	Pattern of files to cleanup in the layer artifact before uploading it

Ruby

Requirements

Ruby >= 2.5
A valid Gemfile file

Options

Option	Type	Default	Description
packageManager	`string`	bundle	Possible values: bundle
dependenciesPath	`string`	Gemfile	Note: Available for `>= 2.x` versions. You can specify a custom path for your `Gemfile`
compatibleRuntimes	`array`	`['ruby']`	Possible values: ruby2.5, ruby2.7
layerOptimization.cleanupPatterns	`array`	check	Pattern of files to cleanup in the layer artifact before uploading it

Python

Requirements

Python >= 2.7
A valid requirements.txt file

Options

Option	Type	Default	Description
packageManager	`string`	pip	Possible values: pip
dependenciesPath	`string`	requirements.txt	Note: Available for `>= 2.x` versions. You can specify a custom path for your `requirements.txt`
compatibleRuntimes	`array`	`['python']`	Possible values: python2.7, python3.x
layerOptimization.cleanupPatterns	`array`	check	Pattern of files to cleanup in the layer artifact before uploading it

Default Serverless Setup

This plugin will set up the following options automatically if not specified in serverless.yml.

Option	Type	Default
package.individually	`bool`	false
package.patterns	`array`	`['node_modules/**']`
package.excludeDevDependencies	`bool`	false

Minimal Policy permissions for CI/CD IAM users

serverless-layers-policy.json

{
   "Version":"2012-10-17",
   "Statement":[
      {
         "Effect":"Allow",
         "Action":[
            "s3:PutObject",
            "s3:GetObject"
         ],
         "Resource": "arn:aws:s3:::examplebucket"
      },
      {
         "Effect":"Allow",
         "Action":[
            "cloudformation:DescribeStacks"
         ],
         "Resource": "*"
      },
      {
         "Effect":"Allow",
         "Action":[
            "lambda:PublishLayerVersion"
         ],
         "Resource": "*"
      }
   ]
}

License

MIT

Contributors

Yes, thank you! This plugin is community-driven, and most of its features are from different authors. Please update the docs and tests and add your name to the package.json file. We try to follow Airbnb's JavaScript Style Guide.

<a href="https://github.com/agutoli/serverless-layers/graphs/contributors"> <img src="https://contrib.rocks/image?repo=agutoli/serverless-layers" /> </a>

Made with contributors-img.