Extraction of parameter name from `id_ssm_parameter_arn` variable.

[michw]

Hello Team,

First, thanks for all Your hard work.

I believe extraction of parameter name introduced by 8afc75c is too aggressive.

Based on AWS docs, You can have SSM parameters organized into hierarchies.

If Your id_ssm_parameter_arn variable starts with / (i.e. /tenant/project/region/github-runner/runner-ami), leading / is lost and scale-up lambda errors out with

...
"module":"lambda.ts","error":
{"name":"Error","location":"file:///var/task/index.js:125007","message":"Failed to lookup runner AMI ID from SSM parameter: tenant/project/region/github-runner/runner-ami
...

[Brend-Smits]

We were seeing the same issue in our environment.

[joemiller]

ran into this too, i believe:

ERROR [runners-4cpu-16gb-arm64-scale-up]: Error processing batch (size: 1): Failed to lookup runner AMI ID from SSM parameter: github-action-runners/packer/ubuntu-jammy-arm64/ami-id, GetParameterError: User: arn:aws:sts::1111111111:assumed-role/runners-4cpu-16gb-arm64-scale-up-lambda-13531bee/runners-4cpu-16gb-arm64-scale-up is not authorized to perform: ssm:GetParameter on resource: arn:aws:ssm:us-east-2:1111111111:* because no identity-based policy allows the ssm:GetParameter action, ignoring batch