# Serverless Layers [](http://www.serverless.com) [](https://github.com/agutoli/serverless-layers/issues) [](https://www.npmjs.com/package/serverless-layers) [](https://www.npmjs.com/package/serverless-layers) [](https://travis-ci.org/agutoli/serverless-layers) [](#contributing)  * 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 ## Options * [NodeJS](#nodejs) * [Ruby](#ruby) * [Python](#python) ## Common Requirements * AWS only (sorry) * Serverless >= 1.34.0 (layers support) ## Install ```bash npm install -D serverless-layers ``` or ```bash serverless plugin install --name serverless-layers ``` Add the plugin to your `serverless.yml` file: ## Single layer config Example: ```yaml 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: ```yaml 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::layer:node-v13-11-0:5 functions: foo: handler: handler.hello bar: handler: handler.hello ```  | 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](https://github.com/agutoli/serverless-layers/blob/master/src/runtimes/nodejs.js) | 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](https://github.com/agutoli/serverless-layers/blob/master/src/runtimes/ruby.js) | 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](https://github.com/agutoli/serverless-layers/blob/master/src/runtimes/python.js) | 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` ```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](https://github.com/airbnb/javascript). Made with [contributors-img](https://contrib.rocks).