feat(cdk): generate Lambda metrics from model

packages/@aws-cdk/aws-lambda/lib/alias.ts

@@ -1,6 +1,6 @@
 import iam = require('@aws-cdk/aws-iam');
 import cdk = require('@aws-cdk/cdk');
-import { FunctionBase, FunctionImportProps, IFunction } from './lambda-ref';
+import { FunctionBase, FunctionImportProps, IFunction } from './function-base';
 import { Version } from './lambda-version';
 import { CfnAlias } from './lambda.generated';
 import { Permission } from './permission';

packages/@aws-cdk/aws-lambda/lib/event-source-mapping.ts

@@ -1,5 +1,5 @@
 import cdk = require('@aws-cdk/cdk');
-import { IFunction } from './lambda-ref';
+import { IFunction } from './function-base';
 import { CfnEventSourceMapping } from './lambda.generated';
 
 export interface EventSourceMappingProps {

packages/@aws-cdk/aws-lambda/lib/event-source.ts

@@ -1,4 +1,4 @@
-import { FunctionBase } from './lambda-ref';
+import { FunctionBase } from './function-base';
 
 /**
  * An abstract class which represents an AWS Lambda event source.

packages/@aws-cdk/aws-lambda/lib/lambda-ref.ts → packages/@aws-cdk/aws-lambda/lib/function-base.ts

@@ -71,13 +71,6 @@ export interface IFunction extends cdk.IConstruct, events.IEventRuleTarget, logs
    */
   metric(metricName: string, props?: cloudwatch.MetricCustomization): cloudwatch.Metric;
 
-  /**
-   * Metric for the Errors executing this Lambda
-   *
-   * @default sum over 5 minutes
-   */
-  metricErrors(props?: cloudwatch.MetricCustomization): cloudwatch.Metric;
-
   /**
    * Metric for the Duration of this Lambda
    *
@@ -275,54 +268,6 @@ export abstract class FunctionBase extends cdk.Construct implements IFunction  {
     }
   }
 
-  /**
-   * Return the given named metric for this Lambda
-   */
-  public metric(metricName: string, props?: cloudwatch.MetricCustomization): cloudwatch.Metric {
-    return new cloudwatch.Metric({
-      namespace: 'AWS/Lambda',
-      metricName,
-      dimensions: { FunctionName: this.functionName },
-      ...props
-    });
-  }
-
-  /**
-   * Metric for the Errors executing this Lambda
-   *
-   * @default sum over 5 minutes
-   */
-  public metricErrors(props?: cloudwatch.MetricCustomization): cloudwatch.Metric {
-    return this.metric('Errors', { statistic: 'sum', ...props });
-  }
-
-  /**
-   * Metric for the Duration of this Lambda
-   *
-   * @default average over 5 minutes
-   */
-  public metricDuration(props?: cloudwatch.MetricCustomization): cloudwatch.Metric {
-    return this.metric('Duration', props);
-  }
-
-  /**
-   * Metric for the number of invocations of this Lambda
-   *
-   * @default sum over 5 minutes
-   */
-  public metricInvocations(props?: cloudwatch.MetricCustomization): cloudwatch.Metric {
-    return this.metric('Invocations', { statistic: 'sum', ...props });
-  }
-
-  /**
-   * Metric for the number of throttled invocations of this Lambda
-   *
-   * @default sum over 5 minutes
-   */
-  public metricThrottles(props?: cloudwatch.MetricCustomization): cloudwatch.Metric {
-    return this.metric('Throttles', { statistic: 'sum', ...props });
-  }
-
   public logSubscriptionDestination(sourceLogGroup: logs.ILogGroup): logs.LogSubscriptionDestination {
     const arn = sourceLogGroup.logGroupArn;
 
@@ -419,4 +364,4 @@ export abstract class FunctionBase extends cdk.Construct implements IFunction  {
     throw new Error(`Invalid principal type for Lambda permission statement: ${JSON.stringify(this.node.resolve(principal))}. ` +
       'Supported: AccountPrincipal, ServicePrincipal');
   }
-}
+}

packages/@aws-cdk/aws-lambda/lib/lambda.ts → packages/@aws-cdk/aws-lambda/lib/function.ts

@@ -4,7 +4,7 @@ import iam = require('@aws-cdk/aws-iam');
 import sqs = require('@aws-cdk/aws-sqs');
 import cdk = require('@aws-cdk/cdk');
 import { Code } from './code';
-import { FunctionBase, FunctionImportProps, IFunction } from './lambda-ref';
+import { FunctionBase, FunctionImportProps, IFunction } from './function-base';
 import { Version } from './lambda-version';
 import { CfnFunction } from './lambda.generated';
 import { ILayerVersion } from './layers';

packages/@aws-cdk/aws-lambda/lib/index.ts

@@ -1,6 +1,6 @@
 export * from './alias';
-export * from './lambda-ref';
-export * from './lambda';
+export * from './function-base';
+export * from './function';
 export * from './layers';
 export * from './permission';
 export * from './pipeline-action';
@@ -13,3 +13,5 @@ export * from './event-source-mapping';
 
 // AWS::Lambda CloudFormation Resources:
 export * from './lambda.generated';
+
+import './lambda-augmentations.generated';

packages/@aws-cdk/aws-lambda/lib/lambda-version.ts

@@ -1,5 +1,5 @@
 import { Construct } from '@aws-cdk/cdk';
-import { IFunction } from './lambda-ref';
+import { IFunction } from './function-base';
 import { CfnVersion } from './lambda.generated';
 
 /**

packages/@aws-cdk/aws-lambda/lib/pipeline-action.ts

@@ -1,7 +1,7 @@
 import codepipeline = require('@aws-cdk/aws-codepipeline-api');
 import iam = require('@aws-cdk/aws-iam');
 import cdk = require('@aws-cdk/cdk');
-import { IFunction } from './lambda-ref';
+import { IFunction } from './function-base';
 
 /**
  * Common properties for creating a {@link PipelineInvokeAction} -

packages/@aws-cdk/aws-lambda/lib/singleton-lambda.ts

@@ -1,7 +1,7 @@
 import iam = require('@aws-cdk/aws-iam');
 import cdk = require('@aws-cdk/cdk');
-import { Function as LambdaFunction, FunctionProps } from './lambda';
-import { FunctionBase, FunctionImportProps, IFunction } from './lambda-ref';
+import { Function as LambdaFunction, FunctionProps } from './function';
+import { FunctionBase, FunctionImportProps, IFunction } from './function-base';
 import { Permission } from './permission';
 
 /**

packages/@aws-cdk/aws-lambda/test/test.lambda.ts

@@ -1058,6 +1058,27 @@ export = {
     test.done();
   },
 
+  'Can use metricErrors on a lambda Function'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const fn = new lambda.Function(stack, 'Function', {
+      code: lambda.Code.inline('xxx'),
+      handler: 'index.handler',
+      runtime: lambda.Runtime.NodeJS810,
+    });
+
+    // THEN
+    test.deepEqual(stack.node.resolve(fn.metricErrors()), {
+      dimensions: { FunctionName: { Ref: 'Function76856677' }},
+      namespace: 'AWS/Lambda',
+      metricName: 'Errors',
+      periodSec: 300,
+      statistic: 'Sum',
+    });
+
+    test.done();
+  },
+
   'addEventSource calls bind'(test: Test) {
     // GIVEN
     const stack = new cdk.Stack();

packages/@aws-cdk/cfnspec/lib/augmentations/AWS_Lambda_Function.json

@@ -0,0 +1,27 @@
+{
+  "metrics": {
+    "namespace": "AWS/Lambda",
+    "dimensions": { "FunctionName": "this.functionName" },
+    "metrics": [
+      {
+        "name": "Throttles",
+        "description": "How often this Lambda is throttled",
+        "isEventCount": true
+      },
+      {
+        "name": "Invocations",
+        "description": "How often this Lambda is invoked",
+        "isEventCount": true
+      },
+      {
+        "name": "Errors",
+        "description": "How many invocations of this Lambda fail",
+        "isEventCount": true
+      },
+      {
+        "name": "Duration",
+        "description": "How long execution of this Lambda takes"
+      }
+    ]
+  }
+}

packages/@aws-cdk/cfnspec/lib/index.ts

@@ -23,6 +23,18 @@ export function resourceSpecification(typeName: string): schema.ResourceType {
   return ret;
 }
 
+/**
+ * Get the resource augmentations for a given type
+ */
+export function resourceAugmentation(typeName: string): schema.ResourceAugmentation {
+  const fileName = typeName.replace(/::/g, '_');
+  try {
+    return require(`./augmentations/${fileName}.json`);
+  } catch (e) {
+    return {};
+  }
+}
+
 /**
  * Return the property specification for the given resource's property
  */

packages/@aws-cdk/cfnspec/lib/schema/augmentation.ts

@@ -0,0 +1,34 @@
+/**
+ * Augmentations for a CloudFormation resource type
+ */
+export interface ResourceAugmentation {
+  /**
+   * Metric augmentations for this resource type
+   */
+  metrics?: ResourceMetricAugmentations;
+}
+
+export interface ResourceMetricAugmentations {
+  namespace: string;
+  dimensions: {[key: string]: string};
+  metrics: ResourceMetric[];
+}
+
+export interface ResourceMetric {
+  /**
+   * Uppercase-first metric name
+   */
+  name: string;
+
+  /**
+   * Documentation line
+   */
+  documentation: string;
+
+  /**
+   * Whether this is an even count (1 gets emitted every time something occurs)
+   *
+   * @default false
+   */
+  isEventCount?: boolean;
+}

packages/@aws-cdk/cfnspec/lib/schema/index.ts

@@ -2,3 +2,4 @@ export * from './base-types';
 export * from './property';
 export * from './resource-type';
 export * from './specification';
+export * from './augmentation';

tools/cfn2ts/lib/augmentation-generator.ts

@@ -0,0 +1,116 @@
+import cfnSpec = require('@aws-cdk/cfnspec');
+import { schema } from '@aws-cdk/cfnspec';
+import { CodeMaker } from 'codemaker';
+import genspec = require('./genspec');
+import { SpecName } from './spec-utils';
+
+export class AugmentationGenerator {
+  private readonly code = new CodeMaker();
+  private readonly outputFile: string;
+
+  constructor(moduleName: string, private readonly spec: schema.Specification) {
+    this.outputFile = `${moduleName}-augmentations.generated.ts`;
+    this.code.openFile(this.outputFile);
+
+    this.code.line(`// Copyright 2012-${new Date().getFullYear()} Amazon.com, Inc. or its affiliates. All Rights Reserved.`);
+    this.code.line();
+    this.code.line('// tslint:disable:max-line-length | This is generated code - line lengths are difficult to control');
+  }
+
+  public emitCode() {
+    for (const resourceTypeName of Object.keys(this.spec.ResourceTypes).sort()) {
+      const aug = cfnSpec.resourceAugmentation(resourceTypeName);
+
+      if (aug.metrics) {
+        this.code.line('import cloudwatch = require("@aws-cdk/aws-cloudwatch");');
+
+        this.emitMetricAugmentations(resourceTypeName, aug.metrics);
+      }
+    }
+  }
+
+  /**
+   * Saves the generated file.
+   */
+  public async save(dir: string) {
+    this.code.closeFile(this.outputFile);
+    return await this.code.save(dir);
+  }
+
+  private emitMetricAugmentations(resourceTypeName: string, metrics: schema.ResourceMetricAugmentations) {
+    const cfnName = SpecName.parse(resourceTypeName);
+    const resourceName = genspec.CodeName.forCfnResource(cfnName);
+    const l2ClassName = resourceName.className.replace(/^Cfn/, '');
+
+    const baseClassName = l2ClassName + 'Base';
+    const interfaceName = 'I' + l2ClassName;
+    const baseClassModule = `./${l2ClassName.toLowerCase()}-base`;
+
+    this.code.line(`import { ${baseClassName} } from "${baseClassModule}";`);
+
+    this.code.openBlock(`declare module "${baseClassModule}"`);
+
+    // Add to the interface
+    this.code.openBlock(`interface ${interfaceName}`);
+    this.emitMetricFunctionDeclaration(cfnName);
+    for (const m of metrics.metrics) {
+      this.emitSpecificMetricFunctionDeclaration(m);
+    }
+    this.code.closeBlock();
+
+    // Add declaration to the base class (implementation added below)
+    this.code.openBlock(`interface ${baseClassName}`);
+    this.emitMetricFunctionDeclaration(cfnName);
+    for (const m of metrics.metrics) {
+      this.emitSpecificMetricFunctionDeclaration(m);
+    }
+    this.code.closeBlock();
+
+    this.code.closeBlock();
+
+    // Emit the monkey patches for all methods
+    this.emitMetricFunction(baseClassName, metrics);
+    for (const m of metrics.metrics) {
+      this.emitSpecificMetricFunction(baseClassName, m);
+    }
+  }
+
+  private emitMetricFunctionDeclaration(resource: SpecName) {
+    this.code.line(`/**`);
+    this.code.line(` * Return the given named metric for this ${resource.resourceName}`);
+    this.code.line(` */`);
+    this.code.line(`metric(metricName: string, props?: cloudwatch.MetricCustomization): cloudwatch.Metric;`);
+  }
+
+  private emitMetricFunction(className: string, metrics: schema.ResourceMetricAugmentations) {
+    this.code.line(`${className}.prototype.metric = function(metricName: string, props?: cloudwatch.MetricCustomization) {`);
+    this.code.line(`  return new cloudwatch.Metric({`);
+    this.code.line(`    namespace: '${metrics.namespace}',`);
+    this.code.line(`    metricName,`);
+
+    const dimStrings = new Array<string>();
+    for (const [key, field] of Object.entries(metrics.dimensions)) {
+      dimStrings.push(`${key}: ${field}`);
+    }
+
+    this.code.line(`    dimensions: { ${dimStrings.join(', ') } },`);
+    this.code.line(`    ...props`);
+    this.code.line(`  });`);
+    this.code.line('};');
+  }
+
+  private emitSpecificMetricFunctionDeclaration(metric: schema.ResourceMetric) {
+    this.code.line(`/**`);
+    this.code.line(` * ${metric.documentation}`);
+    this.code.line(` *`);
+    this.code.line(` * ${metric.isEventCount ? 'Sum' : 'Average'} over 5 minutes`);
+    this.code.line(` */`);
+    this.code.line(`metric${metric.name}(props?: cloudwatch.MetricCustomization): cloudwatch.Metric;`);
+  }
+
+  private emitSpecificMetricFunction(className: string, metric: schema.ResourceMetric) {
+    this.code.line(`${className}.prototype.metric${metric.name} = function(props?: cloudwatch.MetricCustomization) {`);
+    this.code.line(`  return this.metric('${metric.name}', { ${metric.isEventCount ? "statistic: 'sum', " : ""}...props });`);
+    this.code.line('};');
+  }
+}

tools/cfn2ts/lib/codegen.ts

@@ -33,7 +33,7 @@ export default class CodeGenerator {
       fingerprint: spec.Fingerprint
     };
 
-    this.code.line('// Copyright 2012-2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.');
+    this.code.line(`// Copyright 2012-${new Date().getFullYear()} Amazon.com, Inc. or its affiliates. All Rights Reserved.`);
     this.code.line('// Generated from the AWS CloudFormation Resource Specification');
     this.code.line('// See: docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-resource-specification.html');
     this.code.line(`// @cfn2ts:meta@ ${JSON.stringify(meta)}`);