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fix(cloudformation): honor LaunchTemplate/MixedInstancesPolicy on CFN AutoScalingGroup#2017

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vieiralucas merged 1 commit into
mainfrom
wt-bh-asg
Jun 28, 2026
Merged

fix(cloudformation): honor LaunchTemplate/MixedInstancesPolicy on CFN AutoScalingGroup#2017
vieiralucas merged 1 commit into
mainfrom
wt-bh-asg

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@vieiralucas vieiralucas commented Jun 28, 2026

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Bug-hunt batch 6 (cycle 6).

The CFN AWS::AutoScaling::AutoScalingGroup provisioner read only the legacy LaunchConfigurationName and hardcoded launch_template: None, so a group declared with a LaunchTemplate (the modern CDK/CFN shape) or a MixedInstancesPolicy was created with no launch spec at all and DescribeAutoScalingGroups reported none. It now parses the LaunchTemplate / LaunchTemplateSpecification block (LaunchTemplateId/LaunchTemplateName + Version) and carries it onto the group.

E2E test asserts a CFN ASG with a LaunchTemplate reports it. Builds clean; clippy -D warnings clean.

(The sibling finding — CFN ASG/RDS minting placeholder instances/DBs with no real container — is the larger architectural "provisioner should spawn through the real runtime" change, tracked separately.)


Summary by cubic

Fixes CloudFormation AWS::AutoScaling::AutoScalingGroup to honor LaunchTemplate and MixedInstancesPolicy. CFN-created groups now retain and report their launch template instead of dropping it.

  • Bug Fixes
    • Parse CFN LaunchTemplate/LaunchTemplateSpecification (LaunchTemplateId/LaunchTemplateName + Version) and persist it to the group; keeps support for LaunchConfigurationName.
    • Add e2e test in fakecloud-e2e verifying DescribeAutoScalingGroups returns the launch template for a CFN ASG.

Written for commit 9234c9c. Summary will update on new commits.

Review in cubic

… AutoScalingGroup

The CFN AWS::AutoScaling::AutoScalingGroup provisioner read only the legacy
LaunchConfigurationName and hardcoded launch_template: None, so a group declared
with a LaunchTemplate (the modern CDK/CFN shape) or a MixedInstancesPolicy was
created with no launch spec at all and DescribeAutoScalingGroups reported none.
It now parses the LaunchTemplate / LaunchTemplateSpecification block
(LaunchTemplateId/LaunchTemplateName + Version) and carries it onto the group.

Adds an e2e test asserting a CFN ASG with a LaunchTemplate reports it.
@vieiralucas vieiralucas merged commit 51deb13 into main Jun 28, 2026
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@vieiralucas vieiralucas deleted the wt-bh-asg branch June 28, 2026 01:39
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