pahud
commented
10 months ago resolveSsmParameterAtLaunch creates the resolve:ssm:{ParameterName} string which will only be resolved at instance launch time rather than cloudformation deployment time so we can't see the imageId until instance is launched.
This means cloudformation does not know if that will be resolved to any imageId because it points to a custom SSM parameter name and we will only know that when a new instance is launched.
check out the following documents for more details:
Using SSM Parameter with Autoscaling and Launch Template Launch an instance using a Systems Manager parameter
mgwidmann
IwoTens
kliuModerna
DinosaurDad
Describe the bug
MachineImage.resolveSsmParameterAtLaunch("...")does not produce the correctimageIdstring required by CloudFormation.As can be seen here: https://github.com/aws/aws-cdk/blob/main/packages/aws-cdk-lib/aws-ec2/lib/machine-image/machine-image.ts#L259
The string produced is
resolve:ssm:${this.parameterName}${versionString}when the CloudFormation documentation states it should be{{resolve:ssm:${this.parameterName}${versionString}}}instead (two extra open and close braces at start and end).CloudFormation Documentation on dynamic SSM parameter references: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/dynamic-references.html
Expected Behavior
The
imageIdvalue is produced with the correct syntax and CloudFormation is able to successfully process the value.Current Behavior
CloudFormation currently fails with the following error message:
Reproduction Steps
Use
MachineImage.resolveSsmParameterAtLaunch("any-ssm-parameter-name")in a LaunchTemplate for an ASG.Possible Solution
Current workaround is to use
MachineImage.fromSsmParameter("any-ssm-parameter-name").Additional Information/Context
No response
CDK CLI Version
2.90.0
Framework Version
No response
Node.js Version
18.17.1
OS
Mac M1
Language
Python
Language Version
3.10.11
Other information
No response