Script: $using:Key variable in a script receives the wrong value

NReilingh commented 4 years ago

Details of the scenario you tried and the problem that is occurring

When a variable in configuration scope named Key is used inside the GetScript, SetScript, or TestScript properties of the Script resource by way of the using: annotation, it is compiled into the .mof file with a value of Credential regardless of what the variable value in the configuration scope actually is.

This works the same way whether importing PSDesiredStateConfiguration or PSDscResources 2.12.0.0.

I don't know if the logic that generates the MOF file is in this repo or not, or whether that would indicate an issue with a different part of DSC, or perhaps a documentation lapse.

The DSC configuration that is used to reproduce the issue (as detailed as possible)

Configuration TestConfig
{
    Import-DscResource -ModuleName PSDscResources -Name Script

    $Key = "My Value"

    Node localhost
    {
        Script TestScript
        {
            GetScript = {
                Write-Verbose "`$Key value is $using:Key"
                # NoOp
            }
            TestScript = {
                Write-Verbose "`$Key value is $using:Key"

                if ($using:Key -eq 'Credential') {
                    return $false
                } else {
                    return $true
                }
            }
            SetScript = {
                Write-Verbose "`$Key value is $using:Key"
                # NoOp
            }
        }
    }
}

The operating system the development system is running

OsName               : Microsoft Windows 10 Pro
OsOperatingSystemSKU : 48
OsArchitecture       : 64-bit
WindowsVersion       : 1903
WindowsBuildLabEx    : 18362.1.amd64fre.19h1_release.190318-1202
OsLanguage           : en-US
OsMuiLanguages       : {en-US}

Version and build of PowerShell the target node is running

Name                           Value
----                           -----
PSVersion                      5.1.18362.145
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.18362.145
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

Version of the DSC module that was used ('dev' if using current dev branch)

2.12.0.0

mhendric commented 4 years ago

Looks like this is reproducible. Looks like the workaround is pretty simple (don't use a variable named $Key), however this should probably be documented. If we want to fix this behavior, I'm not sure if we should do it here, or only do it in xPSDesiredStateConfiguration. @PlagueHO and @johlju , what's your thoughts on this?

MOF output With $Key Variable:

/*
@TargetNode='localhost'
@GeneratedBy=Mike
@GenerationDate=09/25/2019 09:57:19
@GenerationHost=DP7510
*/

instance of MSFT_ScriptResource as $MSFT_ScriptResource1ref
{
ResourceID = "[Script]TestScript";
 GetScript = "$Key ='Credential'\n\n                Write-Verbose \"`$Key value is $Key\"\n                # NoOp\n            ";
 TestScript = "$Key ='Credential'\n\n                Write-Verbose \"`$Key value is $Key\"\n\n                if ($Key -eq 'Credential') {\n                    return $false\n                } else {\n                    return $true\n                }\n            ";
 SourceInfo = "D:\\Test.ps1::9::9::Script";
 SetScript = "$Key ='Credential'\n\n                Write-Verbose \"`$Key value is $Key\"\n                # NoOp\n            ";
 ModuleName = "PSDscResources";
 ModuleVersion = "2.12.0.0";

 ConfigurationName = "TestConfig";

};
instance of OMI_ConfigurationDocument

                    {
 Version="2.0.0";

                        MinimumCompatibleVersion = "1.0.0";

                        CompatibleVersionAdditionalProperties= {"Omi_BaseResource:ConfigurationName"};

                        Author="Mike";

                        GenerationDate="09/25/2019 09:57:19";

                        GenerationHost="DP7510";

                        Name="TestConfig";

                    };

MOF Output With $NotKey Variable (instead of $Key):

/*
@TargetNode='localhost'
@GeneratedBy=Mike
@GenerationDate=09/25/2019 09:56:12
@GenerationHost=DP7510
*/

instance of MSFT_ScriptResource as $MSFT_ScriptResource1ref
{
ResourceID = "[Script]TestScript";
 GetScript = "$NotKey ='My Value'\n\n                Write-Verbose \"`$NotKey value is $NotKey\"\n                # NoOp\n            ";
 TestScript = "$NotKey ='My Value'\n\n                Write-Verbose \"`$NotKey value is $NotKey\"\n\n                if ($NotKey -eq 'Credential') {\n                    return $false\n                } else {\n                    return $true\n                }\n            ";
 SourceInfo = "D:\\Test.ps1::9::9::Script";
 SetScript = "$NotKey ='My Value'\n\n                Write-Verbose \"`$NotKey value is $NotKey\"\n                # NoOp\n            ";
 ModuleName = "PSDscResources";
 ModuleVersion = "2.12.0.0";

 ConfigurationName = "TestConfig";

};
instance of OMI_ConfigurationDocument

                    {
 Version="2.0.0";

                        MinimumCompatibleVersion = "1.0.0";

                        CompatibleVersionAdditionalProperties= {"Omi_BaseResource:ConfigurationName"};

                        Author="Mike";

                        GenerationDate="09/25/2019 09:56:12";

                        GenerationHost="DP7510";

                        Name="TestConfig";

                    };