fix(appconfig): allow multiple environment monitor roles to be created (#27243)

Currently, when adding multiple monitors under an environment, users are seeing the following error

```
Error: There is already a Construct with name 'Role' in Environment [MyEnvironment]
```

Before the logical id for any monitor role that is created was just `Role`. In this change, we use the monitor index in the logical id so there aren't any repeats in logical id's. This is also why there is a change in the integ test snapshot, since the logical id was refactored.

----

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

Author: chenjane-dev

packages/@aws-cdk/aws-appconfig-alpha/lib/environment.ts

@@ -236,10 +236,10 @@ export class Environment extends EnvironmentBase {
       applicationId: this.applicationId,
       name: this.name,
       description: this.description,
-      monitors: this.monitors?.map((monitor) => {
+      monitors: this.monitors?.map((monitor, index) => {
         return {
           alarmArn: monitor.alarm.alarmArn,
-          alarmRoleArn: monitor.alarmRole?.roleArn || this.createAlarmRole(monitor.alarm.alarmArn).roleArn,
+          alarmRoleArn: monitor.alarmRole?.roleArn || this.createAlarmRole(monitor.alarm.alarmArn, index).roleArn,
         };
       }),
     });
@@ -256,7 +256,7 @@ export class Environment extends EnvironmentBase {
     this.application.addExistingEnvironment(this);
   }
 
-  private createAlarmRole(alarmArn: string): iam.IRole {
+  private createAlarmRole(alarmArn: string, index: number): iam.IRole {
     const policy = new iam.PolicyStatement({
       effect: iam.Effect.ALLOW,
       actions: ['cloudwatch:DescribeAlarms'],
@@ -265,7 +265,7 @@ export class Environment extends EnvironmentBase {
     const document = new iam.PolicyDocument({
       statements: [policy],
     });
-    const role = new iam.Role(this, 'Role', {
+    const role = new iam.Role(this, `Role${index}`, {
       roleName: PhysicalName.GENERATE_IF_NEEDED,
       assumedBy: new iam.ServicePrincipal('appconfig.amazonaws.com'),
       inlinePolicies: {

packages/@aws-cdk/aws-appconfig-alpha/test/environment.test.ts

@@ -147,7 +147,7 @@ describe('environment', () => {
           },
           AlarmRoleArn: {
             'Fn::GetAtt': [
-              'MyEnvironmentRoleC08961D3',
+              'MyEnvironmentRole01C8C013F',
               'Arn',
             ],
           },
@@ -177,6 +177,80 @@ describe('environment', () => {
     });
   });
 
+  test('environment with monitors with two alarms', () => {
+    const stack = new cdk.Stack();
+    const app = new Application(stack, 'MyAppConfig');
+    new Environment(stack, 'MyEnvironment', {
+      name: 'TestEnv',
+      application: app,
+      monitors: [
+        {
+          alarm: new Alarm(stack, 'Alarm1', {
+            threshold: 5,
+            evaluationPeriods: 5,
+            metric: new Metric(
+              {
+                namespace: 'aws',
+                metricName: 'myMetric',
+              },
+            ),
+          }),
+        },
+        {
+          alarm: new Alarm(stack, 'Alarm2', {
+            threshold: 5,
+            evaluationPeriods: 5,
+            metric: new Metric(
+              {
+                namespace: 'aws',
+                metricName: 'myMetric',
+              },
+            ),
+          }),
+        },
+      ],
+    });
+
+    Template.fromStack(stack).resourceCountIs('AWS::CloudWatch::Alarm', 2);
+    Template.fromStack(stack).resourceCountIs('AWS::IAM::Role', 2);
+    Template.fromStack(stack).hasResourceProperties('AWS::AppConfig::Environment', {
+      Name: 'TestEnv',
+      ApplicationId: {
+        Ref: 'MyAppConfigB4B63E75',
+      },
+      Monitors: [
+        {
+          AlarmArn: {
+            'Fn::GetAtt': [
+              'Alarm1F9009D71',
+              'Arn',
+            ],
+          },
+          AlarmRoleArn: {
+            'Fn::GetAtt': [
+              'MyEnvironmentRole01C8C013F',
+              'Arn',
+            ],
+          },
+        },
+        {
+          AlarmArn: {
+            'Fn::GetAtt': [
+              'Alarm2A7122E13',
+              'Arn',
+            ],
+          },
+          AlarmRoleArn: {
+            'Fn::GetAtt': [
+              'MyEnvironmentRole135A2CEE4',
+              'Arn',
+            ],
+          },
+        },
+      ],
+    });
+  });
+
   test('from environment arn', () => {
     const stack = new cdk.Stack();
     const env = Environment.fromEnvironmentArn(stack, 'MyEnvironment',

packages/@aws-cdk/aws-appconfig-alpha/test/integ.environment.js.snapshot/appconfigenvironmentDefaultTestDeployAssert75BD28E7.assets.json

@@ -18,7 +18,7 @@
     "Threshold": 10
    }
   },
-  "MyEnvironmentRoleC08961D3": {
+  "MyEnvironmentRole01C8C013F": {
    "Type": "AWS::IAM::Role",
    "Properties": {
     "AssumeRolePolicyDocument": {
@@ -72,7 +72,7 @@
       },
       "AlarmRoleArn": {
        "Fn::GetAtt": [
-        "MyEnvironmentRoleC08961D3",
+        "MyEnvironmentRole01C8C013F",
         "Arn"
        ]
       }