powershell not able to find software installed in the same script

Question

I have written the below powershell script in the userdata section of a AWS windows EC2 stack creation cloudformation script. I am able to install the AWSCLI using the script but the script is not recognizing 'aws s3 cp' command after install cmdlet. When I login to the EC2 instance I am able to run the aws s3 cp command sucessfully from the powershell prompt. Can anybody tell what I am doing wrong.

{
    "contents":[
        "<powershell> ","\n",
        "$awscliurl = \"https://s3.amazonaws.com/aws-cli/AWSCLI64.msi\"  \n",
        "$awsclidownloadloc = \"C:/Windows/Temp/AWSCLI64.msi\"  \n",
        "(New-Object System.Net.WebClient).DownloadFile($awscliurl, $awsclidownloadloc)   \n",
        "$argstr =  \"/I  C:\\Windows\\Temp\\AWSCLI64.msi  /quiet /L*v   ./awscli-output.log\"  \n",
        "Start-Process msiexec.exe -Wait -ArgumentList $argstr   \n",
        "Start-Process powershell.exe  -RedirectStandardOutput  c:\\s3out.txt  -RedirectStandardError c:\\s3err.out  -Wait -ArgumentList \"aws s3 cp s3://mybucket/myfile.exe  c:\\myfile.exe\"  \n",
        "</powershell>"
    ]
}

When I look at s3err.out I see the below

aws : The term 'aws' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again. At line:1 char:1 + aws s3 cp s3://mybucket/myfile.exe c:\myfile.exe + ~~~ + CategoryInfo : ObjectNotFound: (aws:String) [], CommandNotFoundException + FullyQualifiedErrorId : CommandNotFoundException

MisterSmith MisterSmith · Accepted Answer · 2018-03-15T20:28:50

"AWS" is an executable file located "C:\Program Files\Amazon\AWSCLI\aws.exe". The system PATH environment variable does not include the AWS CLI directory when the user data script started, so it cant find it even after its been installed. When you login you get the updated PATH that will include the cli hence it works when you login and test manually.

In your userdata you should be able to substitute "aws" for the absolute path but you will need to ensure its properly escaped.

The following is untested, but i think should work. Using the PowerShell ` escape character you can include double quotes inside a double quoted string...

-ArgumentList "`"C:\Program Files\Amazon\AWSCLI\aws.exe`" cp ..."

To make this JSON friendly we need to further escape the double quotes so the full line would become:

"Start-Process powershell.exe  -RedirectStandardOutput  c:\\s3out.txt  -RedirectStandardError c:\\s3err.out  -Wait -ArgumentList \"`\"C:\Program Files\Amazon\AWSCLI\aws.exe`\" s3 cp s3://mybucket/myfile.exe  c:\\myfile.exe\"  \n",

An alternative approach would be to use the PowerShell cmdlet for S3:

Read-S3Object -BucketName mybucket -Key myfile.exe -File c:\\myfile.exe

powershell not able to find software installed in the same script

2 Answers