ssm automation document input in AWS-RunShellScript not substituting variable - amazon-web-services

Question

I am trying to run a command in bash where part of the command is substituted from a variable that I created in a previous step, however the string substitution is not working. I have tried many variations of this with single, double quotes, etc but cant not get it to work.
mainSteps:
- name: getIps
action: 'aws:invokeLambdaFunction'
timeoutSeconds: 1200
maxAttempts: 1
onFailure: Abort
inputs:
FunctionName: Automation-GetIPs
Payload: '{"asg": "Staging_web_ASG"}'
outputs:
- Name: asg_ips
Selector: $.Payload.IPs
Type: StringList
- name: updatelsync
action: 'aws:runCommand'
timeoutSeconds: 1200
inputs:
DocumentName: AWS-RunShellScript
InstanceIds:
- '{{ InstanceID }}'
Parameters:
commands:
- 'echo {{getIps.asg_ips}} > /root/asg_ips.test'
In the above code. I set asg_ips in step1 who's OutputPayload is as follows :
{"Payload":{"IPs": ["172.xx.x.xxx", "172.xx.x.xxx"]},"StatusCode":200}
but for input in the 2nd step, it shows as follows...
{"commands":["echo {{getIps.asg_ips}} > /root/asg_ips.test"]}
I need to get it to show something like this...
{"commands":["echo ["172.xx.x.xxx", "172.xx.x.xxx"] > /root/asg_ips.test"]}

Answer 1

Based on the comments.
The issue was caused by incorrect use of outputs in aws:invokeLambdaFunction SSM action. Specifically, the lambda action does not have outputs attribute as shown in the linked documentation:
name: invokeMyLambdaFunction
action: aws:invokeLambdaFunction
maxAttempts: 3
timeoutSeconds: 120
onFailure: Abort
inputs:
FunctionName: MyLambdaFunction
In contrast, as a side note, outputs attribute is valid in aws:executeAwsApi.
Therefore, the solution is to directly refer to the Payload returned by the lambda action:
mainSteps:
- name: getIps
action: 'aws:invokeLambdaFunction'
timeoutSeconds: 1200
maxAttempts: 1
onFailure: Abort
inputs:
FunctionName: Automation-GetIPs
Payload: '{"asg": "Staging_web_ASG"}'
- name: updatelsync
action: 'aws:runCommand'
timeoutSeconds: 1200
inputs:
DocumentName: AWS-RunShellScript
InstanceIds:
- '{{ InstanceID }}'
Parameters:
commands:
- 'echo {{getIps.Payload}} > /root/asg_ips.test'
The side effect is that now asg_ips.test needs to be post-processed to get the IP ranges values.