Public/func_Update-ConfigFileTokens.ps1
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Function Update-ConfigFileTokens { <# .SYNOPSIS Replace tokens in a file with values. .DESCRIPTION Finds tokens in a given file and replace them with values. It is best used to replace configuration values in a release pipeline. .PARAMETER InputFile The file containing the tokens. .PARAMETER OutputFile The output file -- if you leave this empty, the input file will be replaced. .PARAMETER Tokens A hashtable containing the tokens and the value that should replace them. .PARAMETER StartTokenPattern The start of the token, e.g. "{{". .PARAMETER EndTokenPattern The end of the token, e.g. "}}". .PARAMETER NullPattern The pattern that is used to signify $null. The reason for using this is that you cannot set an environment variable to null, so instead, set the environment variable to this pattern, and this script will replace the token with an empty string. .PARAMETER NoWarning If this is used, the script will not warn about tokens that cannot be found in the input file. This is useful when using environment variables to replace tokens since there will be a lot of warnings that aren't really warnings. .EXAMPLE config.template.json: { "url": "{{URL}}", "username": "{{USERNAME}}", "password": "{{PASSWORD}}" } Update-Tokens ` -InputFile config.template.json ` -OutputFile config.json ` -Tokens @{URL="http://localhost:8080";USERNAME="admin";PASSWORD="Test123"} ` -StartTokenPattern "{{" ` -EndTokenPattern "}}" config.json (result): { "url": "http://localhost:8080", "username": "admin", "password": "Test123" } #> [CmdletBinding()] param( [string]$InputFile, [string]$OutputFile = $null, [Hashtable]$Tokens, [string]$StartTokenPattern = '{{', [string]$EndTokenPattern = '}}', [string]$NullPattern = ":::NULL:::", [switch]$NoWarning ) function GetTokenCount($line) { ($line | Select-String -Pattern "$($StartTokenPattern).+?$($EndTokenPattern)" -AllMatches).Matches.Count } # If the OutputFile is null, we will write to a temporary file if ([string]::IsNullOrWhiteSpace($OutputFile)) { Write-Verbose "OutputFile was omitted. Replacing InputFile." $OutputFile = [System.IO.Path]::GetTempFileName() $ReplaceInputFile = $true } # Empty OutputFile if it already exists if (Test-Path -Path $OutputFile) { Write-Verbose "Clearing file $OutputFile" Clear-Content -Path $OutputFile } # Go through each line of the InputFile and replace the tokens with their values $totalTokens = 0 $missedTokens = 0 $usedTokens = New-Object -TypeName "System.Collections.ArrayList" (Get-Content $InputFile) | ForEach-Object { $line = $_ $totalTokens += GetTokenCount($line) foreach ($key in $Tokens.Keys) { $token = "$($StartTokenPattern)$($key)$($EndTokenPattern)" $value = $Tokens.$key if ($line -match $token) { $usedTokens.Add($key) | Out-Null if ($value -eq $NullPattern) { $value = "" } Write-Verbose "Replacing $token with $value" $line = $line -replace "$token", "$value" } } $missedTokens += GetTokenCount($line) $line | Out-File -Append -Encoding UTF8 -FilePath $OutputFile } # If no OutputFile was given, we will replace the InputFile with the temporary file if ($ReplaceInputFile) { Get-Content -Path $OutputFile | Out-File -FilePath $InputFile -Encoding UTF8 } # Write warning if there were tokens given in the Token parameter which were not replaced if (!$NoWarning -and $usedTokens.Count -ne $Tokens.Count) { $unusedTokens = New-Object -TypeName "System.Collections.ArrayList" foreach ($token in $Tokens.Keys) { if (!$usedTokens.Contains($token)) { $unusedTokens.Add($token) | Out-Null } } Write-Warning "The following tokens were not used: $($unusedTokens)" } # Write status message -- warn if there were tokens in the file that were not replaced $message = "Processed: $($InputFile) ($($totalTokens - $missedTokens) out of $totalTokens tokens replaced)" if ($missedTokens -gt 0) { Write-Warning $message } else { Write-Verbose $message } } |