How can I access pre-defined Release Management variables in a Powershell script?

Question

According to the documentation , there are a bunch of predefined variables available for the tasks which run in an environment for Release Management. How do I access these variables from within a Powershell script?

For example: the System.TeamProject variable is defined, and should return the current TFS TeamProject. However, when I write:

Write-Host "environment var: $env:System.TeamProjectId"

The output in the log file is:

2016-06-07T09:26:49.5537161Z environment var: release.TeamProject

However, in the Initialize log file, the following is displayed:

4 2016-06-07T09:26:40.4121001Z Environment variables available are below.  Note that these environment variables can be referred to in the task (in the ReleaseDefinition) by replacing "_" with "." e.g. AGENT_NAME environment variable can be referenced using Agent.Name in the ReleaseDefinition: 
 ...
34 2016-06-07T09:26:40.4277002Z [SYSTEM_COLLECTIONID] --> [2043d9ba-7ec9-43f0-8e6c-96a8b28f55d8]
35 2016-06-07T09:26:40.4277002Z [SYSTEM_TEAMPROJECTID] --> [9718773d-2aee-4625-91c6-80de16301479]
36 2016-06-07T09:26:40.4277002Z [SYSTEM_TEAMPROJECT] --> [MyProject]
37 2016-06-07T09:26:40.4277002Z [SYSTEM_CULTURE] --> [en-US]

So this means the variable is there. I tried $(System.TeamProject) as suggested somewhere else, but that fails with The term ... is not recognized -error.

Also, the variables which I have configured myself in the Release Definition, eg priority , I am able to access with $env:priority .

As a workaround I can create my own parameters in the script, and pass them in the Arguments field in the task definition, but this kind of defeats the purpose.

Answer 1

Use curly braces because the variable name contains . . Example:

PS C:\> ${Env:System.TeamProject} = "Var contents"
PS C:\> ${Env:System.TeamProject}
Var contents
PS C:\> Write-Host "Prefix - $Env:System.TeamProject"
Prefix - .TeamProject
PS C:\> Write-Host "Prefix - ${Env:System.TeamProject}"
Prefix - Var contents