Variables don't persist when using persistentrunspace environment

PowerShell Universal
1 
Product: PowerShell Universal
Version: 1.5.19

Hi

My issue is that variables set in one API call don’t persist in other calls even though a persistent runspace environment is used

It’s possible I don’t quite understand how persistent runspaces are supposed to work but I feel that I have things set up correctly, please let me know what I’m doing wrong here

environments.ps1:

New-PSUEnvironment -Name "env" -path "/usr/bin/pwsh" -PersistentRunspace

settings.ps1:

Set-PSUSetting -APIEnvironment 'env'

endpoints.ps1:

New-PSUEndpoint -Url "/test1" -Endpoint {
    $x = 1
    return $x
}

New-PSUEndpoint -Url "/test2" -Endpoint {
    return $x
}

I would expect GET /test2 to return 1 here, but the variable is empty

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Thanks

2

Persistent runspaces will persist variables but PSU is still using a runspace pool. You’re likely hitting two separate runspaces. You will want to use the cache if you want to persist information across runspaces.

3

Hey @ScalbyLausisJim , you can also use a global variable to persist between APIs. The persistent Runspaces switch needs to be enabled in the environment.

# API 1
$Global:xobj = "Hello"

# API 2
$xobj

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2 Likes
4

Hi Adam
Thanks for the advice, that works to an extent, but I am having trouble properly deserializing the output of Get-PSUCache (am working with custom classes that contain other custom classes)

Are the PSUCache commands simply wrappers around Import/Export-CliXml cmdlets? Or is there anything extra going on behind the scenes? I have written a method to deserialize the cached objects which works correctly when dealing with the output of Import-CliXml but not with Get-PSUCache

I am tempted to use Export-CliXml directly instead of the PSUCache commands, unless there is some reason not to? Or alternatively use global variables as suggested above

Thanks

5

The PSUCache cmdlets using the PSSerializer class which serializes and deserializes CliXml.

With the introduction of the $Cache scope in PSUv2, you’ll be able to set items into memory without the CliXml serialization.

New-PSUEndpoint -Url "/test1" -Endpoint {
    $Cache:x = 1
    return $Cache:x
}

New-PSUEndpoint -Url "/test2" -Endpoint {
    return $Cache:x
}

The cache scope will go across runspaces and won’t using any type of serialization.

6

Thanks Adam, this works great

I will note that I didn’t need to set up a persistent environment or set an API environment for the variables in the $cache scope to persist, not sure if this is intended

Cheers

7

That’s intentional. Glad it’s working!

1 Like