Reference value from state’s input, using JSONPath syntax in a SSMSendCommand API step through parameter which expects an array - json

Question

I have on a AWS state machine the following step defined for api aws-sdk:ssm:sendCommand
{
"Type": "Task",
"Parameters": {
"DocumentName.$": "$.result.DocumentName",
"InstanceIds.$": "$..Dimensions[?(#.Name=~/.*InstanceId.*/)].Value",
"MaxErrors": "0",
"MaxConcurrency": "100%",
"CloudWatchOutputConfig": {
"CloudWatchLogGroupName": "diskspace-log",
"CloudWatchOutputEnabled": true
},
"Parameters": {
"workingDirectory": [
""
],
"executionTimeout": [
"3600"
],
"commands": [
"echo -------------------Mounting volume without signals $..Dimensions[?(#.Name=~/.*device.*/)].Value---------------------",
"echo",
"mount $..Dimensions[?(#.Name=~/.*device.*/)].Value"
]
}
}
}
The section: "commands": [] expects an array.
"commands" should accept input reference as any other parameter in the schema, so in theory will be posible to use json path parameters (Example: "size.$": "$.product.details.size") for referencing needed parameters from input.
https://docs.aws.amazon.com/step-functions/latest/dg/input-output-inputpath-params.html
This following example works without using input referencing :
"commands": [
"echo -------------------Mounting /dev/ebs---------------------",
"echo",
"mount /dev/ebs"
]
But I need to reference from input, hardcoded values won't work for me. I tried, but no working.
"commands": [
"echo -------------------Mounting volume without signals $..Dimensions[?(#.Name=~/.*device.*/)].Value---------------------",
"echo",
"mount $..Dimensions[?(#.Name=~/.*device.*/)].Value"
]
Also tried, not working also:
"commands.$": "States.Array(States.Format('echo -------------------Mounting volume without signals {} ---------------------', $..Dimensions[?(#.Name=~/.*device.*/)].Value),'echo',States.Format('mount {}', $..Dimensions[?(#.Name=~/.*device.*/)].Value))"
I believe some of the provided intrinsic functions will help on achieving the expected result but I'm lost on how to properly set up the syntax.
https://docs.aws.amazon.com/step-functions/latest/dg/amazon-states-language-intrinsic-functions.html#asl-intrsc-func-arrays
The step calls a RunShellScript type of documentCommand.
And executes the commands provided on parameters in the step of the state machine.
I got on the output:
States.Format('echo -------------------Mounting volume without signals {} ---------------------', $..Dimensions[?(#.Name=~/.*device.*/)].Value)'
Its not detecting the input reference, I expect to output.
-------------------Mounting volume without signals /dev/ebs ---------------------
and in the background execute:
mount /dev/ebs

Answer 1

I was able to send the commands through a Pass State Flow, here is the definition:
{
"Type": "Pass",
"Next": "SendCommand",
"ResultPath": "$.ForArgs",
"Parameters": {
"Params": {
"Args": [
{
"Arg1": "ec2-metadata -i"
},
{
"Arg2": "echo"
},
{
"Arg3.$": "States.Format('echo -------------------Mounting volume without signals {} ---------------------', States.ArrayGetItem($..Dimensions[?(#.Name=~/.*device.*/)].Value, 0))"
},
{
"Arg4": "echo"
},
{
"Arg5.$": "States.Format('mount {}', States.ArrayGetItem($..Dimensions[?(#.Name=~/.*device.*/)].Value, 0))"
},
{
"Arg6.$": "States.Format('echo Checking if device {} is mounted', States.ArrayGetItem($..Dimensions[?(#.Name=~/.*device.*/)].Value, 0))"
},
{
"Arg7.$": "States.Format('if findmnt --source \"{}\" >/dev/null', States.ArrayGetItem($..Dimensions[?(#.Name=~/.*device.*/)].Value, 0))"
},
{
"Arg8": "\tthen echo device is mounted"
},
{
"Arg9": "\telse echo device is not mounted"
},
{
"Arg10": "fi"
}
]
}
}
}
Next on the sendCommandApi:
"commands.$": "$.ForArgs.Params.Args[*][*]"