TerraformUtil

0.5.0

Set-TFAlias.ps1

<#
.SYNOPSIS
    Set the "terraform" alias like tfenv
#>
function Set-TFAlias {
    [CmdletBinding(DefaultParameterSetName = 'Help')]
    param (
        [Parameter(ParameterSetName = 'Initialize', Mandatory = $true)]
        [Switch]$Initialize,
        [Parameter(ParameterSetName = 'Latest', Mandatory = $true)]
        [Switch]$Latest,
        [Parameter(ParameterSetName = 'Version', Mandatory = $true)]
        [semver]$Version,
        [Parameter(ParameterSetName = 'FromVersionFile', Mandatory = $true)]
        [Switch]$FromVersionFile,
        [Parameter(ParameterSetName = 'Help', Mandatory = $false)]
        [Switch]$Help
    )
    switch ($PSCmdlet.ParameterSetName) {
        'Initialize' {
            # initialize
            InvokeTFAliasInitialize
            return
        }
        'Latest' {
            InvokeTFAliasLatestVersion
            return
        }
        'Version' {
            InvokeTFAliasVersion -Version $Version
            return
        }
        'FromVersionFile' {
            InvokeTFAliasFromVersionFile 
            return
        }
        Default {
            ShowHelpMessage
        }
    }
}

function ShowHelpMessage () {
    @"
Set the "terraform" alias like tfenv
 
Usage:
  -Initialize Setup TFAlias environment
  -Latast Set alias to the latest Terraform version
  -Version X.Y.Z Set alias to Terraform ver.X.Y.Z
  -FromVersionFile Set alias from .terraform-version file
    * Currently supported "latest", "latest:<regex>", "x.y.z"
  -Help Show this message
 
Example:
  PS > Set-TFAlias -Initialize # Initialize and download the latest version
  PS > terraform version
  Terraform vX.Y.Z
  PS > Set-TFAlias -Version 1.2.3 # download ver.1.2.3 and set alias
  PS > terraform version
  Terraform v1.2.3
"@ | Out-Host
}

function InvokeTFAliasInitialize([Switch]$Update) {
    $aliasRoot = GetTFAliasRoot

    # Check Alias path
    if (-not (Test-Path -LiteralPath $aliasRoot -PathType Container)) {
        WriteInfo ("Create TFAlias path : {0}" -f $aliasRoot)
        [void](New-Item -Path $aliasRoot -ItemType Directory)
    }

    InvokeTFAliasLatestVersion
}

function InvokeTFAliasLatestVersion () {
    $aliasRoot = GetTFAliasRoot

    # Check Alias path
    if (-not (Test-Path -LiteralPath $aliasRoot -PathType Container)) {
        Write-Warning ("Alias path {0} not found. Do Set-TFAlias -Initialize first." -f $aliasRoot)
        return  
    }

    # get the latest version
    $version = Find-TFRelease -Latest | Select-Object -ExpandProperty Version
    Writeinfo ("Terraform v{0} is the latest version." -f $version)
    InvokeTFAliasVersion -Version $version 
}

function InvokeTFAliasVersion ([semver]$Version) {
    $aliasRoot = GetTFAliasRoot
    $ailasAppPath = Join-Path $aliasRoot 'terraform'

    # Check Alias path
    if (-not (Test-Path -LiteralPath $aliasRoot -PathType Container)) {
        Write-Warning ("Alias root path {0} not found. Do Set-TFAlias -Initialize first." -f $aliasRoot)
        return  
    }

    # Check terraform binary
    $binaryName = GetTerraformBinaryName
    $versionPath = Join-Path $ailasAppPath "$Version"
    $versionBinaryPath = Join-Path $versionPath $binaryName
    if (-not (Test-Path -LiteralPath $versionPath -PathType Container)) {
        [void](New-Item -Path $versionPath -ItemType Directory)  
    }
    if (-not (Test-Path -LiteralPath $versionBinaryPath -PathType Leaf)) {
        # Install Terraform
        WriteInfo ("Install Terraform v{0} to {1}..." -f $Version, $versionPath)
        Save-TFBinary -Version $Version -DestinationPath $versionPath  
    }

    # Set alias
    Writeinfo ("Set the v{0} terraform alias." -f $Version)
    DoSetAlias -BinaryPath $versionBinaryPath
}

function InvokeTFAliasFromVersionFile () {
    # Check .terraform-version exists
    if (-not (Test-Path -LiteralPath './.terraform-version' -PathType Leaf)) {
        Write-Warning (".terraform-version file not found.")
        return  
    }
    
    # TODO : implement more formal parser
    $rowString = (Get-Content -LiteralPath './.terraform-version' | Select-Object -First 1).Trim()
    if ('latest-allowed' -eq $rowString) {
        Write-Warning 'latest-allowed is not supported.'
        return 
    }
    if ('min-required' -eq $rowString) {
        Write-Warning 'min-required is not supported.'
        return 
    }
    if ('latest' -eq $rowString) {
        Write-Verbose 'Detect the latest version'
        InvokeTFAliasLatestVersion
        return 
    }
    if ($rowString -match '^latest:(?<match_exp>.+)$' ) {
        $matchExp = $Matches.match_exp
        Write-Verbose ("version match expression : {0}" -f $matchExp)
        # exclude prerelease
        $matchVersion = Find-TFVersion -Filter { "$_" -match $matchExp -and (-not $_.PreReleaseLabel) } -Take 1
        if (-not $matchVersion) {
            Write-Warning ('Failed to detect Terraform version. (expression = {0})' -f $matchExp)
            return
        }
        Write-Verbose ('Detect version {0}' -f $matchVersion)
        InvokeTFAliasVersion -Version $matchVersion
        return 
    }
    try {
        $version = [semver]$rowString
        Write-Verbose ('Detect version {0}' -f $version)
        InvokeTFAliasVersion -Version $version
        return
    } catch {
        # do nothing
    }
    Write-Warning ('Failed to parse .terraform-version : {0}' -f $rowString)
}

function DoSetAlias ([string]$BinaryPath) {
    # Set-Alias global
    Set-Alias -Name 'terraform' -Value $BinaryPath -Scope Global    
    # Register auto completion
    Register-TFArgumentCompleter
}