chore(logs): Adding a public method to access the physical name of th…

…e log group (#14947)

This PR adds a public method `logGroupPhysicalName()` to access the physical name of a log group which is a private property of the `Resource` class.

This change is needed to enable using KMS keys with log groups for use with ECS exec.
Related: #13618

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/aws-logs/lib/log-group.ts

@@ -72,6 +72,11 @@ export interface ILogGroup extends IResource {
    * Give the indicated permissions on this log group and all streams
    */
   grant(grantee: iam.IGrantable, ...actions: string[]): iam.Grant;
+
+  /**
+   * Public method to get the physical name of this log group
+   */
+  logGroupPhysicalName(): string;
 }
 
 /**
@@ -173,6 +178,14 @@ abstract class LogGroupBase extends Resource implements ILogGroup {
       scope: this,
     });
   }
+
+  /**
+   * Public method to get the physical name of this log group
+   * @returns Physical name of log group
+   */
+  public logGroupPhysicalName(): string {
+    return this.physicalName;
+  }
 }
 
 /**

packages/@aws-cdk/aws-logs/test/test.loggroup.ts

@@ -335,6 +335,24 @@ export = {
 
     test.done();
   },
+
+  'correctly returns physical name of the log group'(test: Test) {
+    // GIVEN
+    const stack = new Stack();
+
+    // WHEN
+    const logGroup = new LogGroup(stack, 'LogGroup', {
+      logGroupName: 'my-log-group',
+    });
+
+    // THEN
+    test.equal(logGroup.logGroupPhysicalName(), 'my-log-group');
+    expect(stack).to(haveResource('AWS::Logs::LogGroup', {
+      LogGroupName: 'my-log-group',
+    }));
+
+    test.done();
+  },
 };
 
 function dataDrivenTests(cases: any[][], body: (test: Test, ...args: any[]) => void) {