NetopsWIFAuth.psm1

<#
  .Synopsis
  Displays a message.
  
  .Description
  Displays a message. Supports a message parameter.
  Will use the default message if no parameter is given.
  
  .Parameter Message
  The message to display.
  
  .Outputs
  System.String
  
  .Example
  # Show the default message.
  Show-Message
  
  .Example
  # Display a specific message.
  Show-Message -Message "Hello World!"
#>

Function Show-Message
{
    param( [string] $Message = "Default Message" )

    $Message
}
# Export-ModuleMember -Function Show-Message

<#
  .Synopsis
  Outputs workload identity credentials files.

  .Description
  Outputs workload identity credentials files.
  Wrapper around the gcloud iam workload-identity-pools create-cred-config command.
  Supports an OutputFolderPath parameter.
  Writes an access token file and a json credentials file to the filesystem:
  - "$OutputFolderPath/access-token-file"
  - "$OutputFolderPath/credentials.json"

  .Parameter Username
  The client_id of the workload, provided as part of the client_credentials by the API marketplace.
  For example: cbe6172c-af90-4735-868e-4a6e20c57396

  .Parameter Password
  The client_secret of the workload, provided as part of the client_credentials by the API marketplace.
  For example: 64947168-d1f6-4a23-8a1b-f262c7a2dcfd6ba1c089-93ae-5a9e-8429-6b932a806ee8

  .Parameter ServiceAccount
  The email address of the GCP service account being authenticated through Workload Identity Federation.
  For example: automation@tu-nfv-svc-test-project-01-np.iam.gserviceaccount.com

  .Parameter OutputFolderPath
  The filesystem path to the folder where the access token file and the json credentials file will be written.
  For example: /artifacts/credentials

  .Example
  Out-WorkloadCredentials -Username "cbe6172c-af90-4735-868e-4a6e20c57396" `
                          -Password "64947168-d1f6-4a23-8a1b-f262c7a2dcfd6ba1c089-93ae-5a9e-8429-6b932a806ee8" `
                          -ServiceAccount "automation@tu-nfv-svc-test-project-01-np.iam.gserviceaccount.com" `
                          -OutputFolderPath "/artifacts/credentials"
  
#>

Function Out-WorkloadCredentials
{
    Param (
        [string] $Username,
        [string] $Password,
        [string] $ServiceAccount,
        [string] $OutputFolderPath
    )

    $SecurePassword = ConvertTo-SecureString -String $Password -AsPlainText -Force
    $Credential = New-Object "System.Management.Automation.PSCredential" -ArgumentList $Username, $SecurePassword
    $Body = @{ grant_type='client_credentials'; }
    $Response = Invoke-WebRequest `
                -Uri https://apigw-st.telus.com/st/token `
                -Authentication Basic `
                -Credential $Credential `
                -Method POST `
                -Body $Body
    
    $AccessToken = $Response.Content | ConvertFrom-Json | Select-Object -ExpandProperty access_token
    $AccessToken | Out-File -FilePath "${OutputFolderPath}/access-token-file"

    $Audience="projects/1022893644241/locations/global/workloadIdentityPools/cdo-telus-idp-wif-its04/providers/cdo-telus-idp-its04"
    gcloud iam workload-identity-pools create-cred-config ${Audience} `
        --service-account=${ServiceAccount} `
        --service-account-token-lifetime-seconds=3600 `
        --output-file="${OutputFolderPath}/credentials.json" `
        --credential-source-file="${OutputFolderPath}/access-token-file"
}

<#
  .Synopsis
  Displays the email address of the GCP Service Account.
  
  .Description
  Displays the email address of the GCP Service Account.
  Supports a ServiceAccountJsonKeyFilePath parameter.
  The email address of the GCP Service Account is parsed from the contents of the Json Service Account key file.
  
  .Parameter ServiceAccountJsonKeyFilePath
  The filesystem path to the Json Service Account key file.
  
  .Outputs
  System.String
  
  .Example
  # Show the email address of the service account contained inside the Json Service Account key file
  Show-ServiceAccount -ServiceAccountJsonKeyFilePath "/var/tmp/service-account-key.json"
#>

Function Show-ServiceAccount {
  Param ([string] $ServiceAccountJsonKeyFilePath)

  $line = $( get-content ${ServiceAccountJsonKeyFilePath} | select-string -Pattern "client_email" )
  $removeCommas = [System.Text.RegularExpressions.Regex]::Replace(${line},",","")
  $removeLabel = [System.Text.RegularExpressions.Regex]::Replace(${removeCommas},"`"client_email`":","")
  $removeQuotes = [System.Text.RegularExpressions.Regex]::Replace(${removeLabel},"`"","")
  $removeSpaces = [System.Text.RegularExpressions.Regex]::Replace(${removeQuotes}," ","")
  $serviceAccount = ${removeSpaces}

  return ${serviceAccount}
}