Position objects or entities as relationships

Question

I am trying to draw some diagrams mimicking examples at awslabs/aws-icons-for-plantuml . There are two issues I am facing (please excuse the loose terminologies):

How to add objects on top of another object/entity?
How to add objects/entities between entities in place of notes or comments?

In the diagram below,

a) I would like to add Role1 on top of vpc or ec2 instance or any boundary to highlight that only r1 can access this resource.

b) I would like to add Role2 entity between EC2 and Queue Service. This is to highlight that r2 has access to SNS message between (not shown).

Code:

@startuml VPC
!define AWSPuml https://raw.githubusercontent.com/awslabs/aws-icons-for-plantuml/v13.1/dist
!include AWSPuml/AWSCommon.puml
!include AWSPuml/AWSSimplified.puml
!include AWSPuml/Compute/EC2.puml
!include AWSPuml/Compute/EC2Instance.puml
!include AWSPuml/Groups/AWSCloud.puml
!include AWSPuml/Groups/VPC.puml
!include AWSPuml/Groups/AvailabilityZone.puml
!include AWSPuml/Groups/PublicSubnet.puml
!include AWSPuml/Groups/PrivateSubnet.puml
!include AWSPuml/NetworkingContentDelivery/VPCNATGateway.puml
!include AWSPuml/SecurityIdentityCompliance/IdentityAccessManagementRole.puml
!include AWSPuml/ApplicationIntegration/SimpleQueueService.puml

hide stereotype
skinparam linetype ortho
AWSCloudGroup(cloud) {

  VPCGroup(vpc) {

    AvailabilityZoneGroup(az_1, "\tAvailability Zone 1\t") {
      PublicSubnetGroup(az_1_public, "Public subnet") {
        VPCNATGateway(az_1_nat_gateway, "NAT gateway", "") #Transparent
      }
      PrivateSubnetGroup(az_1_private, "Private subnet") {
        EC2Instance(az_1_ec2_1, "Instance", "") #Transparent
      }

  IdentityAccessManagementRole("r1", "Role1", " ")
  IdentityAccessManagementRole("r2", "Role2", " ")

  SimpleQueueService("sqs", "Queue Service", " ")

    az_1_ec2_1 .u.> az_1_nat_gateway
    az_1_ec2_1 --> sqs:[$r1]
    }

  }
}
@enduml

Corresponding diagram:

I would like the roles to be placed at positions shown by arrowhead:

I'm not sure what you mean by "on top of." It might be better if you can edit an image (by hand, or with annotations) to show how you want things positioned. — Fuhrmanator, Aug 18 '22 at 14:42
@Fuhrmanator updated image. Place `Role1` and `Role2` be at the end of arrow (on top of availability zone and in between Instance and Queue Service). Hope that clarifies the problem. — jimmu, Aug 18 '22 at 15:55

score 1 · Accepted Answer · answered Aug 18 '22 at 18:37

The strategy is to use the <img:...> inside of labels or names of elements. I found some insight to make your role icons smaller in an issue on the aws-icons-for-plantuml repo. You may feel like adjusting the {scale=..} values.

To position Role2, I made a hidden rectangle above az_1 whose name is the image wrapped with the role name in bold. Because it's a rectangle name, the font is bigger than the label used on an association (as in Role1). These are "hacks" and so as you can see they're far from perfect.

@startuml VPC
!define AWSPuml https://raw.githubusercontent.com/awslabs/aws-icons-for-plantuml/v13.1/dist
!include AWSPuml/AWSCommon.puml
!include AWSPuml/AWSSimplified.puml
!include AWSPuml/Compute/EC2.puml
!include AWSPuml/Compute/EC2Instance.puml
!include AWSPuml/Groups/AWSCloud.puml
!include AWSPuml/Groups/VPC.puml
!include AWSPuml/Groups/AvailabilityZone.puml
!include AWSPuml/Groups/PublicSubnet.puml
!include AWSPuml/Groups/PrivateSubnet.puml
!include AWSPuml/NetworkingContentDelivery/VPCNATGateway.puml
!include AWSPuml/SecurityIdentityCompliance/IdentityAccessManagementRole.puml
!include AWSPuml/ApplicationIntegration/SimpleQueueService.puml

skinparam Rectangle<<hidden>> {
    BackgroundColor transparent
    BorderColor transparent
}

hide stereotype
skinparam linetype ortho
AWSCloudGroup(cloud) {

  VPCGroup(vpc) {

    'IdentityAccessManagementRole("r1", "Role1", " ")
    rectangle "<img:AWSPuml/SecurityIdentityCompliance/IdentityAccessManagementRole.png{scale=0.4}>\n<b>Role1</b>" as r1  <<hidden>>
    AvailabilityZoneGroup(az_1, "\tAvailability Zone 1\t") {
        PublicSubnetGroup(az_1_public, "Public subnet") {
            VPCNATGateway(az_1_nat_gateway, "NAT gateway", "") #Transparent
        }
        PrivateSubnetGroup(az_1_private, "Private subnet") {
            EC2Instance(az_1_ec2_1, "Instance", "") #Transparent
        }

        SimpleQueueService("sqs", "Queue Service", " ")

        az_1_ec2_1 .u.> az_1_nat_gateway
        'IdentityAccessManagementRole("r1", "Role1", " ")
        az_1_ec2_1 --> sqs:"<img:AWSPuml/SecurityIdentityCompliance/IdentityAccessManagementRole.png{scale=0.4}>  \n<b>Role2  </b>"
    }

    az_1 -[hidden]up- r1 

  }
}
@enduml

Here's a PNG of that:

PNG

Awesome, wasn't aware of the `` construct. This works as expected, thanks! — jimmu, Aug 18 '22 at 18:44

Position objects or entities as relationships

1 Answers1