Support for using Lambda Layers

docs/providers/aws/guide/functions.md

@@ -334,6 +334,25 @@ Real-world use cases where tagging your functions is helpful include:
 - Keeping track of legacy code (e.g. tag functions which use outdated runtimes: `runtime: nodejs0.10`)
 - ...
 
+## Layers
+
+Using the `layers` configuration makes it possible for your function to use
+[Lambda Layers](https://LINK-TO-AWS-DOCS-ABOUT-LAYERS)
+
+```yml
+functions:
+  hello:
+    handler: handler.hello
+    layers:
+      - arn:aws:lambda:region:XXXXXX:layer:LayerName:Y
+```
+
+Layers can be used in combination with `runtime: provided` to implement your own custom runtime on
+AWS Lambda.
+
+To publish Lambda Layers, check out the
+[serverless-lambda-layers plugin](https://github.com/serverless/lambda-layers-plugin).
+
 ## Log Group Resources
 
 By default, the framework will create LogGroups for your Lambdas. This makes it easy to clean up your log groups in the case you remove your service, and make the lambda IAM permissions much more specific and secure.

docs/providers/aws/guide/serverless.yml.md

@@ -158,6 +158,8 @@ functions:
         - .travis.yml
       artifact: path/to/my-artifact.zip # Own package that should be use for this specific function. You must provide this file.
       individually: true # Enables individual packaging for specific function. If true you must provide package for each function. Defaults to false
+    layers: # An optional list Lambda Layers to use
+      - arn:aws:lambda:region:XXXXXX:layer:LayerName:Y # Layer Version ARN
     events: # The Events that trigger this Function
       - http: # This creates an API Gateway HTTP endpoint which can be used to trigger this function.  Learn more in "events/apigateway"
           path: users/create # Path for this endpoint

lib/plugins/aws/package/compile/functions/index.js

@@ -314,6 +314,10 @@ class AwsCompileFunctions {
     newFunction.DependsOn = [this.provider.naming.getLogGroupLogicalId(functionName)]
       .concat(newFunction.DependsOn || []);
 
+    if (functionObject.layers && _.isArray(functionObject.layers)) {
+      newFunction.Properties.Layers = functionObject.layers;
+    }
+
     const functionLogicalId = this.provider.naming
       .getLambdaLogicalId(functionName);
     const newFunctionObject = {

lib/plugins/aws/package/compile/functions/index.test.js

@@ -2056,5 +2056,87 @@ describe('AwsCompileFunctions', () => {
         ).to.throw(Error);
       });
     });
+
+    it('should not set unset properties when not specified in yml (layers, vpc, etc)', () => {
+      const s3Folder = awsCompileFunctions.serverless.service.package.artifactDirectoryName;
+      const s3FileName = awsCompileFunctions.serverless.service.package.artifact
+        .split(path.sep).pop();
+
+      awsCompileFunctions.serverless.service.functions = {
+        func: {
+          handler: 'func.function.handler',
+          name: 'new-service-dev-func',
+        },
+      };
+      const compiledFunction = {
+        Type: 'AWS::Lambda::Function',
+        DependsOn: [
+          'FuncLogGroup',
+          'IamRoleLambdaExecution',
+        ],
+        Properties: {
+          Code: {
+            S3Key: `${s3Folder}/${s3FileName}`,
+            S3Bucket: { Ref: 'ServerlessDeploymentBucket' },
+          },
+          FunctionName: 'new-service-dev-func',
+          Handler: 'func.function.handler',
+          MemorySize: 1024,
+          Role: { 'Fn::GetAtt': ['IamRoleLambdaExecution', 'Arn'] },
+          Runtime: 'nodejs4.3',
+          Timeout: 6,
+        },
+      };
+
+      return expect(awsCompileFunctions.compileFunctions()).to.be.fulfilled
+      .then(() => {
+        expect(
+          awsCompileFunctions.serverless.service.provider.compiledCloudFormationTemplate
+            .Resources.FuncLambdaFunction
+        ).to.deep.equal(compiledFunction);
+      });
+    });
+
+    it('should set Layers when specified', () => {
+      const s3Folder = awsCompileFunctions.serverless.service.package.artifactDirectoryName;
+      const s3FileName = awsCompileFunctions.serverless.service.package.artifact
+        .split(path.sep).pop();
+
+      awsCompileFunctions.serverless.service.functions = {
+        func: {
+          handler: 'func.function.handler',
+          name: 'new-service-dev-func',
+          layers: ['arn:aws:xxx:*:*'],
+        },
+      };
+      const compiledFunction = {
+        Type: 'AWS::Lambda::Function',
+        DependsOn: [
+          'FuncLogGroup',
+          'IamRoleLambdaExecution',
+        ],
+        Properties: {
+          Code: {
+            S3Key: `${s3Folder}/${s3FileName}`,
+            S3Bucket: { Ref: 'ServerlessDeploymentBucket' },
+          },
+          FunctionName: 'new-service-dev-func',
+          Handler: 'func.function.handler',
+          MemorySize: 1024,
+          Role: { 'Fn::GetAtt': ['IamRoleLambdaExecution', 'Arn'] },
+          Runtime: 'nodejs4.3',
+          Timeout: 6,
+          Layers: ['arn:aws:xxx:*:*'],
+        },
+      };
+
+      return expect(awsCompileFunctions.compileFunctions()).to.be.fulfilled
+      .then(() => {
+        expect(
+          awsCompileFunctions.serverless.service.provider.compiledCloudFormationTemplate
+            .Resources.FuncLambdaFunction
+        ).to.deep.equal(compiledFunction);
+      });
+    });
   });
 });