Raw JSON / Dict in Troposphere Attribute

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Will Dawe

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Feb 18, 2025, 5:51:05 AMFeb 18

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I'm currently trying to define an EC2 ASG MixedInstancePolicy in my Troposphere script. I have an stack parameter which is a CommaDelimitedList of instance types, which i'd like to use in my MixedInstancePolicy.

However, i'm running into an issue whereby Troposphere requires certain attributes to be a specific class. I can't use raw JSON in certain places.

```

    MixedInstancesPolicy={
        "LaunchTemplate": {
            "LaunchTemplateSpecification": LaunchTemplateSpecification(
                LaunchTemplateId=Ref(launch_template),
                Version=GetAtt(launch_template, "LatestVersionNumber")
            ),
            "Overrides": {
                "Fn::ForEach::InstanceTypes": [
                    "InstanceType",
                    Ref(instance_types),
                    [
                        LaunchTemplateOverrides(
                            InstanceType="${InstanceType}",
                        )
                    ]
                ]
            }
        }
    }

```

The above results in the below error:

```

TypeError: <class 'troposphere.autoscaling.AutoScalingGroup'>: ComponentAutoScalingGroup.MixedInstancesPolicy is <class 'dict'>, expected <class 'troposphere.autoscaling.MixedInstancesPolicy'>

```

Is there a way to override this requirement? So that I can use a dictionary instead of an expected class to output my required contents?

Many thanks :)

Will Dawe

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Feb 18, 2025, 7:28:52 AMFeb 18

to cloudtools-dev

Turns out...

> It cannot be used in the Format version, Description, Metadata, Transform, Parameters, Mappings, Rules, or Hooks sections

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-foreach.html