Support CW events. Add SERVERLESS_ALIAS variable to aliased functions.

Author: Frank Schmid

README.md

@@ -32,11 +32,6 @@ hook into the deployment process.
 Additionally the new `alias` command is added to Serverless which offers some
 functionality for aliases.
 
-## Interoperability
-
-Care has to be taken when using other plugins that modify the CF output too.
-I will add configuration instructions in this section for these plugin combinations.
-
 ## Deploy the default alias
 
 The default alias (for the stage) is deployed just by doing a standard stage
@@ -226,6 +221,19 @@ the alias stack has been removed.
 The alias plugin is compatible with all standard Serverless commands and switches.
 For example, you can use `--noDeploy` and the plugin will behave accordingly.
 
+## Interoperability
+
+Care has to be taken when using other plugins that modify the CF output too.
+I will add configuration instructions in this section for these plugin combinations.
+
+### [serverless-plugin-warmup](https://github.com/FidelLimited/serverless-plugin-warmup)
+
+The warmup plugin will keep your Lambdas warm and reduce the cold start time
+effectively. When using the plugin, it must be listed **before** the alias plugin
+in the plugin list of _serverless.yml_. The warmup lambda created by the plugin
+will be aliased too, so that the warmup plugin can be configured differently
+per deployed alias.
+
 ## Test it
 
 In case you wanna test how it behaves, I provided a predefined test service in
@@ -307,6 +315,8 @@ and _serverless.service.provider.deployedAliasTemplates[]_.
 
 * 0.5.0-alpha1 Fixes a bug with deploying event sources introduced with 0.4.0
                Use new event model introduced in SLS 1.12. Needs SLS 1.12 or greater from now on.
+							 Add support for CW events.
+							 Set SERVERLESS_ALIAS environment variable on deployed functions.
 * 0.4.0-alpha1 APIG support fixed. Support external IAM roles. BREAKING.
 * 0.3.4-alpha1 Bugfixes. IAM policy consolitaion. Show master alias information.
 * 0.3.3-alpha1 Bugfixes. Allow manual resource overrides. Allow methods attached to APIG root resource.

lib/aliasRestructureStack.js

@@ -91,6 +91,12 @@ module.exports = {
 			}
 		};
 
+		// Set SERVERLESS_ALIAS environment variable
+		_.forOwn(stageStack.Resources, resource => {
+			if (resource.Type === 'AWS::Lambda::Function') {
+				_.set(resource, 'Properties.Environment.Variables.SERVERLESS_ALIAS', this._alias);
+			}
+		});
 
 		const versions = _.assign({}, _.pickBy(stageStack.Resources, [ 'Type', 'AWS::Lambda::Version' ]));
 		if (!_.isEmpty(versions)) {
@@ -313,6 +319,55 @@ module.exports = {
 		return BbPromise.resolve([ currentTemplate, aliasStackTemplates, currentAliasStackTemplate ]);
 	},
 
+	aliasHandleCWEvents(currentTemplate, aliasStackTemplates, currentAliasStackTemplate) {
+
+		const stageStack = this._serverless.service.provider.compiledCloudFormationTemplate;
+		const aliasStack = this._serverless.service.provider.compiledCloudFormationAliasTemplate;
+
+		const cwEvents = _.assign({}, _.pickBy(_.get(stageStack, 'Resources', {}), [ 'Type', 'AWS::Events::Rule' ]));
+		const cwEventLambdaPermissions =
+				_.assign({},
+					_.pickBy(_.pickBy(stageStack.Resources, [ 'Type', 'AWS::Lambda::Permission' ]),
+					['Properties.Principal', 'events.amazonaws.com']));
+
+		_.forOwn(cwEvents, (cwEvent, name) => {
+			// Reference alias as FunctionName
+			const targetRefs = utils.findAllReferences(_.get(cwEvent, 'Properties.Targets'));
+			cwEvent.DependsOn = cwEvent.DependsOn || [];
+			_.forEach(targetRefs, ref => {
+				const functionName = _.replace(ref.ref, /LambdaFunction$/, '');
+				_.set(cwEvent.Properties.Targets, ref.path, { Ref: `${functionName}Alias` });
+				cwEvent.DependsOn.push(`${functionName}Alias`);
+			});
+
+			// Remove mapping from stage stack
+			delete stageStack.Resources[name];
+		});
+
+		// Move event subscriptions to alias stack
+		_.defaults(aliasStack.Resources, cwEvents);
+
+		// Adjust permission to reference the function aliases
+		_.forOwn(cwEventLambdaPermissions, (permission, name) => {
+			const targetFunctionRef = utils.findAllReferences(_.get(permission, 'Properties.FunctionName'));
+			const functionName = _.replace(targetFunctionRef[0].ref, /LambdaFunction$/, '');
+
+			// Adjust references and alias permissions
+			permission.Properties.FunctionName = { Ref: `${functionName}Alias` };
+
+			// Add dependency on function alias
+			permission.DependsOn = [ `${functionName}Alias` ];
+
+			delete stageStack.Resources[name];
+		});
+
+		// Add all alias stack owned resources
+		_.defaults(aliasStack.Resources, cwEventLambdaPermissions);
+
+		// Forward inputs to the promise chain
+		return BbPromise.resolve([ currentTemplate, aliasStackTemplates, currentAliasStackTemplate ]);
+	},
+
 	aliasFinalize(currentTemplate, aliasStackTemplates, currentAliasStackTemplate) {
 		const aliasStack = this._serverless.service.provider.compiledCloudFormationAliasTemplate;
 
@@ -336,6 +391,7 @@ module.exports = {
 		.spread(this.aliasHandleFunctions)
 		.spread(this.aliasHandleApiGateway)
 		.spread(this.aliasHandleEvents)
+		.spread(this.aliasHandleCWEvents)
 		.spread(this.aliasFinalize)
 		.then(() => BbPromise.resolve());
 	}

lib/stackops/apiGateway.js

@@ -95,7 +95,11 @@ module.exports = function(currentTemplate, aliasStackTemplates, currentAliasStac
 		}
 
 		// Fetch lambda permissions, methods and resources. These have to be updated later to allow the aliased functions.
-		const apiLambdaPermissions = _.assign({}, _.pickBy(stageStack.Resources, [ 'Type', 'AWS::Lambda::Permission' ]));
+		const apiLambdaPermissions =
+				_.assign({},
+					_.pickBy(_.pickBy(stageStack.Resources, [ 'Type', 'AWS::Lambda::Permission' ]),
+					['Properties.Principal', 'apigateway.amazonaws.com']));
+
 		const apiMethods = _.assign({}, _.pickBy(stageStack.Resources, [ 'Type', 'AWS::ApiGateway::Method' ]));
 		//const apiResources = _.assign({}, _.pickBy(stageStack.Resources, [ 'Type', 'AWS::ApiGateway::Resource' ]));
 		const aliases = _.assign({}, _.pickBy(aliasStack.Resources, [ 'Type', 'AWS::Lambda::Alias' ]));