将标签动态应用到 AWS CloudFormation 堆栈

Question

I have been searching for a way to dynamically applied tags to AWS CloudFormation Stack resource. I could not find the right answer. Below is my CloudFormation stack resource.

AWSTemplateFormatVersion: '2010-09-09' 
Parameters: 
 ami:
  Type: String
 instanceType:
  Type: String
 blockdevice:
  Type: String
Resources: 
 ec2Stack: 
  Type: AWS::CloudFormation::Stack 
  Properties: 
   TemplateURL: !Sub "${s3ArtifactPath}/ec2/ec2-base-app.yml"
   Parameters:
     ami: !Ref ami
     instanceType: !Ref instanceType
     blockdevice: !Ref blockdevice
   Tags:
     - Key: sampleKey
       Value: sampleValue

I have been trying to find a way where I only pass a list or simply ref a parameter is Tags section. Here is what I did

AWSTemplateFormatVersion: '2010-09-09' 
Parameters: 
 ami:
   Type: String
 instanceType:
   Type: String
   Default: nbs
   MinLength: 3
   MaxLength: 5
 blockdevice:
   Type: String
 tagsJsonList:
   Type: String
   Default: '[{"key1":"value1"}, {"key2":"value2"}]'
Resources: 
 ec2Stack: 
     Type: AWS::CloudFormation::Stack 
     Properties: 
       TemplateURL: !Sub "${s3ArtifactPath}/ec2/ec2-base-app.yml"
       Parameters:
         ami: !Ref ami
         instanceType: !Ref instanceType
         blockdevice: !Ref blockdevice
       Tags: !Ref tagsJsonList

I was expecting the CloudFormation to formulate the tag list from the variable. The purpose behind this will be that we'll be able to scale in the list and the new tags key-value pairs will be added automatically. This approach did not work.

I also tried the following way

AWSTemplateFormatVersion: '2010-09-09' 
Parameters: 
  ami:
    Type: String
  instanceType:
    Type: String
    Default: nbs
    MinLength: 3
    MaxLength: 5
  blockdevice:
    Type: String
Resources: 
  ec2Stack: 
      Type: AWS::CloudFormation::Stack 
      Properties: 
        TemplateURL: !Sub "${s3ArtifactPath}/ec2/ec2-base-app.yml"
        Parameters:
          ami: !Ref ami
          instanceType: !Ref instanceType
          blockdevice: !Ref blockdevice
        Tags:
          - Key: !Select [0, !Split ["=", !Select [0, !Split [",", !ImportValue someExport] ] ] ]
            Value: !Select [1, !Split ["=", !Select [0, !Split [",", !ImportValue someExport] ] ] ]

# someExport -->  k1=v1,k2=v2,k3=v3

1. One problem with this approach is that I can't use Sub intrinsic function to make the someExport variable dynamic.
2. Other problem is that I'll have to write multiple statements for Key, Value statements for applying multiple tags

Answer 1

I know you got it working already, but you could try the tag string as:

'{"key1":"value1", "key2":"value2"}'