feat: allow specifying regions/accounts at a more granular level (#533)

This allows users to target different regions/account for specific
things within a facade rather than relying on 1 facade per
region/account with the facade's global settings, so something like:

```ts
this.facade
  .monitorDynamoTable({
    ...,
  })
  .monitorDynamoTable({
    ...,
    region: <some_other_region>,
    account: <some_other_account>,
  })
```

---

_By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache-2.0 license_

Author: Eugene Cheung

API.md

@@ -417,6 +417,48 @@ Now, this widget will be added to both dashboards and will show different conten
 * Dashboard Name: "ExampleDashboards-Infrastructure"
   * Content: "This shows metrics for the AWS Infrastructure supporting your hosted service"
 
+### Cross-account cross-Region Dashboards
+
+Facades can be configured for different regions/accounts as a whole:
+
+```ts
+new MonitoringFacade(stack, "Monitoring", {
+  metricFactoryDefaults: {
+    // Different region/account than what you're deploying to
+    region: "us-west-2",
+    account: "01234567890",
+  }
+});
+```
+
+Or at a more granular level:
+
+```ts
+monitoring
+  .monitorDynamoTable({
+    // Table from the same account/region
+    table: Table.fromTableName(stack, "ImportedTable", "MyTableName"),
+  })
+  .monitorDynamoTable({
+    // Table from another account/region
+    table: Table.fromTableArn(
+      stack,
+      "XaXrImportedTable",
+      "arn:aws:dynamodb:us-west-2:01234567890:table/my-other-table",
+    ),
+    region: "us-west-2",
+    account: "01234567890",
+  });
+```
+
+The order of precedence of the region/account values is:
+
+1. The individual metric factory's props (e.g. via the `monitorDynamoTable` props).
+1. The facade's `metricFactoryDefaults` props.
+1. The region/account that the stack is deployed to.
+
+Note that certain metrics are based on [math expressions](https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/using-metric-math.html) and cannot be alarmed upon in a cross-account cross-Region context, and you will see an error at synthesis time.
+
 ### Monitoring scopes
 
 You can monitor complete CDK construct scopes using an aspect. It will automatically discover all monitorable resources within the scope recursively and add them to your dashboard.

README.md

@@ -1,15 +1,33 @@
 import { MetricFactory } from "./MetricFactory";
 
 export interface BaseMetricFactoryProps {
-  // TODO: this will eventually include other common things like account/region
+  /**
+   * Region where the metrics exist.
+   *
+   * @default The region configured by the construct holding the Monitoring construct
+   * @see https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Cross-Account-Cross-Region.html
+   */
+  readonly region?: string;
+
+  /**
+   * Account where the metrics exist.
+   *
+   * @default The account configured by the construct holding the Monitoring construct
+   * @see https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Cross-Account-Cross-Region.html
+   */
+  readonly account?: string;
 }
 
 export abstract class BaseMetricFactory<
   PropsType extends BaseMetricFactoryProps,
 > {
   protected readonly metricFactory: MetricFactory;
+  protected readonly account?: string;
+  protected readonly region?: string;
 
-  constructor(metricFactory: MetricFactory, _props: PropsType) {
+  constructor(metricFactory: MetricFactory, props: PropsType) {
     this.metricFactory = metricFactory;
+    this.account = props.account;
+    this.region = props.region;
   }
 }

lib/common/metric/BaseMetricFactory.ts

@@ -31,21 +31,6 @@ export interface MetricFactoryDefaults extends BaseMetricFactoryProps {
    * @default - DefaultMetricPeriod
    */
   readonly period?: Duration;
-
-  /**
-   * Region where the metrics exist.
-   *
-   * @default The region configured by the construct holding the Monitoring construct
-   * @see https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Cross-Account-Cross-Region.html
-   */
-  readonly region?: string;
-  /**
-   * Account where the metrics exist.
-   *
-   * @default The account configured by the construct holding the Monitoring construct
-   * @see https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Cross-Account-Cross-Region.html
-   */
-  readonly account?: string;
 }
 
 export interface MetricFactoryProps {

lib/common/metric/MetricFactory.ts

@@ -38,6 +38,9 @@ export class CertificateManagerMetricFactory extends BaseMetricFactory<Certifica
       this.dimensionsMap,
       undefined,
       Namespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 }

lib/monitoring/aws-acm/CertificateManagerMetricFactory.ts

@@ -94,6 +94,9 @@ export class ApiGatewayMetricFactory extends BaseMetricFactory<ApiGatewayMetricF
       this.dimensionsMap,
       undefined,
       ApiGatewayNamespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -105,6 +108,9 @@ export class ApiGatewayMetricFactory extends BaseMetricFactory<ApiGatewayMetricF
       this.dimensionsMap,
       undefined,
       ApiGatewayNamespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -126,6 +132,9 @@ export class ApiGatewayMetricFactory extends BaseMetricFactory<ApiGatewayMetricF
       this.dimensionsMap,
       undefined,
       ApiGatewayNamespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -169,6 +178,9 @@ export class ApiGatewayMetricFactory extends BaseMetricFactory<ApiGatewayMetricF
       this.dimensionsMap,
       undefined,
       ApiGatewayNamespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 }

lib/monitoring/aws-apigateway/ApiGatewayMetricFactory.ts

@@ -101,6 +101,9 @@ export class ApiGatewayV2HttpApiMetricFactory extends BaseMetricFactory<ApiGatew
       this.dimensionsMap,
       undefined,
       ApiGatewayNamespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -122,6 +125,9 @@ export class ApiGatewayV2HttpApiMetricFactory extends BaseMetricFactory<ApiGatew
       this.dimensionsMap,
       undefined,
       ApiGatewayNamespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -186,6 +192,9 @@ export class ApiGatewayV2HttpApiMetricFactory extends BaseMetricFactory<ApiGatew
       this.dimensionsMap,
       undefined,
       ApiGatewayNamespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -198,6 +207,9 @@ export class ApiGatewayV2HttpApiMetricFactory extends BaseMetricFactory<ApiGatew
       this.dimensionsMap,
       undefined,
       ApiGatewayNamespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 }

lib/monitoring/aws-apigatewayv2/ApiGatewayV2HttpApiMetricFactory.ts

@@ -75,6 +75,9 @@ export class AppSyncMetricFactory extends BaseMetricFactory<AppSyncMetricFactory
       this.dimensionsMap,
       undefined,
       Namespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -86,6 +89,9 @@ export class AppSyncMetricFactory extends BaseMetricFactory<AppSyncMetricFactory
       this.dimensionsMap,
       undefined,
       Namespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -97,6 +103,9 @@ export class AppSyncMetricFactory extends BaseMetricFactory<AppSyncMetricFactory
       this.dimensionsMap,
       undefined,
       Namespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -108,6 +117,9 @@ export class AppSyncMetricFactory extends BaseMetricFactory<AppSyncMetricFactory
       this.dimensionsMap,
       undefined,
       Namespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -119,6 +131,9 @@ export class AppSyncMetricFactory extends BaseMetricFactory<AppSyncMetricFactory
       this.dimensionsMap,
       undefined,
       Namespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 
@@ -140,6 +155,9 @@ export class AppSyncMetricFactory extends BaseMetricFactory<AppSyncMetricFactory
       this.dimensionsMap,
       undefined,
       Namespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 

lib/monitoring/aws-appsync/AppSyncMetricFactory.ts

@@ -72,6 +72,7 @@ export class CloudFrontDistributionMetricFactory extends BaseMetricFactory<Cloud
       CloudFrontNamespace,
       undefined,
       CloudFrontDefaultMetricRegion,
+      this.account,
     );
   }
 
@@ -108,6 +109,7 @@ export class CloudFrontDistributionMetricFactory extends BaseMetricFactory<Cloud
       CloudFrontNamespace,
       undefined,
       CloudFrontDefaultMetricRegion,
+      this.account,
     );
   }
 
@@ -121,6 +123,7 @@ export class CloudFrontDistributionMetricFactory extends BaseMetricFactory<Cloud
       CloudFrontNamespace,
       undefined,
       CloudFrontDefaultMetricRegion,
+      this.account,
     );
   }
 
@@ -139,6 +142,7 @@ export class CloudFrontDistributionMetricFactory extends BaseMetricFactory<Cloud
       CloudFrontNamespace,
       undefined,
       CloudFrontDefaultMetricRegion,
+      this.account,
     );
   }
 
@@ -152,6 +156,7 @@ export class CloudFrontDistributionMetricFactory extends BaseMetricFactory<Cloud
       CloudFrontNamespace,
       undefined,
       CloudFrontDefaultMetricRegion,
+      this.account,
     );
   }
 
@@ -165,6 +170,7 @@ export class CloudFrontDistributionMetricFactory extends BaseMetricFactory<Cloud
       CloudFrontNamespace,
       undefined,
       CloudFrontDefaultMetricRegion,
+      this.account,
     );
   }
 
@@ -178,6 +184,7 @@ export class CloudFrontDistributionMetricFactory extends BaseMetricFactory<Cloud
       CloudFrontNamespace,
       undefined,
       CloudFrontDefaultMetricRegion,
+      this.account,
     );
   }
 }

lib/monitoring/aws-cloudfront/CloudFrontDistributionMetricFactory.ts

@@ -39,6 +39,9 @@ export class CloudWatchLogsMetricFactory extends BaseMetricFactory<CloudWatchLog
       this.dimensionsMap,
       undefined,
       CloudWatchLogsNamespace,
+      undefined,
+      this.region,
+      this.account,
     );
   }
 }