[SOLVED] Value of property VPCZoneIdentifier must be of type List of String

Issue

"wordpressASG": {
      "Type": "AWS::AutoScaling::AutoScalingGroup",
      "Properties": {
        "AvailabilityZones": [
          "ap-southeast-2a",
          "ap-southeast-2b"
        ],
        "VPCZoneIdentifier": [
          {
            "ref": "subnetA"
          },
          {
            "ref": "subnetB"
          }
        ],
        "MinSize": "0",
        "HealthCheckGracePeriod": 300,
        "MaxSize": "0",
        "Cooldown": "300",
        "LaunchTemplate": {
          "LaunchTemplateId": {
            "Ref": "wordpressTemplate"
          },
          "Version": {
            "Fn::GetAtt": [
              "wordpressTemplate",
              "LatestVersionNumber"
            ]
          }
        },
        "MetricsCollection": [
          {
            "Granularity": "1Minute",
            "Metrics": [
              "GroupMinSize",
              "GroupMaxSize"
            ]
          }
        ],
        "TargetGroupARNs": [
          {
            "Ref": "wordpressTG"
          }
        ]
      }
    }

Probably not a new question, but all examples are of using a subnet parameter. List needs to be string, but ref Should give strings for this thing. The Subnets are being created in the same script.

Solution

Based on the comments.

The issue was the use ref instead of Ref when listing subsets in VPCZoneIdentifier.

Answered By - Marcin