(ec2): import an existing AutoScalingGroup with a Role

[joon73]

I'm trying to referring an existing AutoScalingGroup from my CodeDeploy with AutoScalingGroup.from_auto_scaling_group_name static method in order to integrate with CodePipeline for automating EC2/On-premise deployment. However, the Role from AutoScalingGroup is not being imported.

Reproduction Steps

• Refer existing AutoScaling Group:
  asg_1 = autoscaling.AutoScalingGroup.from_auto_scaling_group_name(self, "AutoScaleGroup", "WSAutoscaleStack-webServerAsgIdASG12345-XXXXXX")

• EC2 Deployment Groups:
  deployment_group = codedeploy.ServerDeploymentGroup(self, "CodeDeployDeploymentGroup", deployment_group_name="MyDeploymentGroup", install_agent=True, auto_scaling_groups=[asg_1])

What did you expect to happen?

Ideally, the referenced resource should be imported as an object, so that I can use it all dependents including iam.role from the resource. (c.f. from CodeDeploy Application Environment configuration, choose the Amazon EC2 Auto Scaling group where the current application revision is deployed)

What actually happened?

The error that I'm getting is as follows:
jsii.errors.JSIIError: Cannot get policy fragment of AMIPipelineStack/AutoScaleGroup, resource imported without a role

Environment

• CDK CLI Version : 1.94.0 (build 2c1c0eb)
• Framework Version:
• Node.js Version: v15.11.0
• OS : macOS Catalina
• Language (Version): Python (3.8.7)

Other

This issue was posted and confirmed. The issue is linked,
https://stackoverflow.com/questions/66748035/refer-import-existing-autoscalinggroup-resource-from-cdk-stack

---

This is 🐛 Bug Report

[peterwoodworth]

Thanks for submitting this issue @joon73, and sorry for the slow response. I'm able to reproduce this on 1.110.1 with Typescript. Looks like this issue has been ran into in a slightly different place before: #4613

Some clarification: Importing the ASG resource doesn't actually get the role that's attached to it. The docs show that the interface doesn't have a role property, and the implementation of the import isn't doing anything other than creating a new class. It's not actually a method which looks up info from AWS

aws-cdk/packages/@aws-cdk/aws-autoscaling/lib/auto-scaling-group.ts

Lines 853 to 865 in 32f00eb

	public static fromAutoScalingGroupName(scope: Construct, id: string, autoScalingGroupName: string): IAutoScalingGroup {
	class Import extends AutoScalingGroupBase {
	public autoScalingGroupName = autoScalingGroupName;
	public autoScalingGroupArn = Stack.of(this).formatArn({
	service: 'autoscaling',
	resource: 'autoScalingGroup:*:autoScalingGroupName',
	resourceName: this.autoScalingGroupName,
	});
	public readonly osType = ec2.OperatingSystemType.UNKNOWN;
	}
	return new Import(scope, id);
	}

However, I'm not sure what the root cause of this issue is. @skinny85 you've tackled this error in the past, can you take a look here?