SSM Command document to run a Powershell command on Windows instances and a shell command on Linux instances. The commands are hard-coded, but could be moved to input parameters.

SsmCommandDocument-RunScript.yml

# SSM Command document to run a Powershell command on Windows instances and a shell command
# on Linux instances. The commands are hard-coded, but could be moved to input parameters.

schemaVersion: "2.2"
description: Run a PowerShell command on Windows instances and a shell command on Linux instances
mainSteps:
- precondition:
    StringEquals: [platformType, Windows]
  action: "aws:runPowerShellScript"
  name: runPowerShellScript
  inputs:
    workingDirectory: C:\Windows\Temp\
    runCommand:
    - $ErrorActionPreference = "Stop"
    - Write-Output "Start script (PowerShell $($PSVersionTable.PSVersion))"

    - '"File contents from Command document!" | Out-File -FilePath C:\Windows\Temp\file.txt'

    - Write-Output "Complete"
- precondition:
    StringEquals: [platformType, Linux]
  action: "aws:runShellScript"
  name: runShellScript
  inputs:
    workingDirectory: /tmp
    runCommand:
    - set -e
    - echo "Start script ($SHELL)"

    - echo "File contents from Command document!" > /tmp/file.txt

    - echo "Complete"