部署自動化 - web.config PowerShell 更新函式庫

. ..\WebConfLib.ps1

# 測試前置作業
function PrepareTest() {
    $appPath = (Get-WebApplication -Site 'Default Web Site' -Name 'ConfLab').PhysicalPath
    Copy-Item "$appPath\web.sample.config" "$appPath\web.config" -Force
    Copy-Item "$appPath\SubFolder\web.sample.config" "$appPath\SubFolder\web.config" -Force
}
PrepareTest

# 測試一 
SetConfPath 'Default Web Site' 'ConfLab'

# 在現有 Attribute 值附加內容
AppendXmlElementAttrs 'appSettings/add[@key="ClientIps"]' @{ value = ";192.168.1.1" }
# 更新 Attrubte 值
SetXmlElementAttrs 'appSettings/add[@key="FOO"]' @{ value = "BAR" }
# 移除 XmlElement
RemoveXmlElement 'appSettings/add[@key="Garbage"]'
# 新增 XmlElement 並設定 Attribute
SetXmlElementAttrs 'system.webServer/httpProtocol/customHeaders/add[@name="X-Frame-Options"]' @{ value = 'SAMEORIGIN' }
# 新增 XmlElement 並設定多項 Attribute
SetXmlElementAttrs 'system.web/httpCookies' @{ requireSSL = 'false'; httpOnlyCookies = 'true' }

CommitConfChanges

# 測試二 進階應用

SetConfPath 'Default Web Site' 'ConfLab' 'SubFolder'

# 依現有 Attribute 值決定新值
$newNum = [int]::Parse((GetXmlElementAttr 'appSettings/add[@key="Number"]' 'value')) + 1
SetXmlElementAttrs 'appSettings/add[@key="Number"]' @{ value = $newNum }
# 執行 XPATH 查詢，依現況決定更新方式
[System.Xml.XmlElement]$node = GetXmlNode 'system.web'
if ($node -and $node.SelectSingleNode('compilation[@debug="true"]')) {
    # 置換 XML
    SetXmlElementInnerXml 'system.web/authorization' @"
<allow users="*" />
"@
}

CommitConfChanges -Force # 不需確認直接更新

$ErrorActionPreference = 'STOP'
# 全域變數
[string]$configPath = ''
[string]$bakPath = ''
[System.Xml.XmlDocument]$xmlDoc = New-Object System.Xml.XmlDocument

# 自動偵測 git.exe 路徑
$gitPath = ''
. where.exe git | ForEach-Object { 
    if ($_.EndsWith('git.exe')) { $gitPath = $_ }
}
if ([string]::IsNullOrEmpty($gitPath) -and (Test-Path $PSScriptRoot\PortableGit\bin\git.exe)) {
    $gitPath = Resolve-Path $PSScriptRoot\PortableGit\bin\git.exe
}

function SetConfPath {
    param (
        [Parameter(Mandatory = $true)][string]$site, 
        [Parameter(Mandatory = $true)][string]$appName, 
        [string]$folder = ''
    )
    $app = Get-WebApplication -Site $site -Name $appName
    if (!$app) { throw "$site/$appName not found" }
    
    $configPath = [IO.Path]::Combine($app.PhysicalPath, $folder, 'web.config')
    Write-Host "### 設定檔路徑 = $configPath" -ForegroundColor Yellow
    # 依時間產生備份資料夾路徑
    $bakPath = Join-Path (Get-Location).Path ('BAK-' + (Get-Date -Format 'yyyyMMddHHmmss'))
    # 備份原檔
    [IO.Directory]::CreateDirectory($bakPath) | Out-Null
    if (Test-Path $configPath) {
        Write-Host "備份舊版 $configPath" -ForegroundColor Cyan
        Copy-Item $configPath (Join-Path $bakPath 'web.orig.config')
    }
    else {
        Write-Host "原本無設定檔" -ForegroundColor Cyan
        '' | Out-File (Join-Path $bakPath 'web.orig.config')
        # 產生空白 web.config
        @"
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
</configuration>
"@ | Out-File $configPath -Encoding utf8
    }
    $xmlDoc.Load($configPath)
    Set-Variable -Name configPath -Value $configPath -Scope 1
    Set-Variable -Name bakPath -Value $bakPath -Scope 1
    Start-Transcript -Path (Join-Path $bakPath "Update.log")
}

function GetXmlNode([string]$xpath, [bool]$autoCreate = $false) {
    $node = $xmlDoc.DocumentElement.SelectSingleNode($xpath) 
    if ($node) { return $node }
    if (!$autoCreate) { return $null }
    $currNode = $xmlDoc.DocumentElement
    $xpath.Split('/') | ForEach-Object {
        $elName = $_
        $m = [System.Text.RegularExpressions.Regex]::Match($elName, "[a-zA-z]+\[@(?<n>.+)=`"(?<v>.+)`"]")
        if ($m.Success) {
            $keyAttrName = $m.Groups['n'].Value
            $keyAttrVal = $m.Groups['v'].Value.Trim("'", "`"")
            $elName = $_.Split('[')[0]
        }
        if (!$currNode.SelectSingleNode($_)) {
            $node = $xmlDoc.CreateElement($elName)    
            if ($keyAttrName) { $node.SetAttribute($keyAttrName, $keyAttrVal) }
            $currNode = $currNode.AppendChild($node) 
        }
        else {
            $currNode = $currNode.SelectSingleNode($_)
        }
    }    
    return $xmlDoc.DocumentElement.SelectSingleNode($xpath)
}

function SetXmlElementAttrs([string]$xpath, [Hashtable]$attrs) {
    $node = (GetXmlNode $xpath $true)
    Write-Host "* 設定屬性：$xpath " -ForegroundColor Yellow
    $attrs.Keys | ForEach-Object {       
        Write-Host "  $_ = $($attrs[$_])" -ForegroundColor White
        $node.SetAttribute([string]$_, [string]$attrs[$_])
    }
}
function GetXmlElementAttr([string]$xpath, [string]$attrName) {
    $node = GetXmlNode $xpath
    if (!$node) { return '' }
    return $node.GetAttribute($attrName)
}

function SetXmlElementInnerXml([string]$xpath, [string]$xml) {
    $node = (GetXmlNode $xpath $true)
    Write-Host "* 設定XML：$xpath" -ForegroundColor Yellow
    Write-Host "  $xml" -ForegroundColor White
    $node.InnerXML = $xml
}
function AppendXmlElementAttrs([string]$xpath, [Hashtable]$attrs) {
    $node = (GetXmlNode $xpath $true)
    Write-Host "* 附加屬性 $xpath" -ForegroundColor Yellow
    $attrs.Keys | ForEach-Object {
        $old = $node.GetAttribute($_)
        $new = $old + [string]$attrs[$_]
        Write-Host "  $old => $new" -ForegroundColor White
        $node.SetAttribute([string]$_, $new)
    }
}
function RemoveXmlElement([string]$xpath) {
    $node = GetXmlNode $xpath
    if ($node) { 
        Write-Host "移除 $xpath" -ForegroundColor Yellow
        $node.ParentNode.RemoveChild($node) | Out-Null 
    }
}
function ShowDiff([string]$origFile, [string]$newFile) {
    if ([string]::IsNullOrEmpty($gitPath)) {
        Write-Host '系統未安裝 Git 或 PortableGit，無法提供修改確認' -ForegroundColor Red
        return;
    }
    "Git [$gitPath]"
    Write-Host "本次異動對照如下，請確認：" -ForegroundColor Yellow
    $header = $true
    . $gitPath diff --no-index $origFile $newFile 2>&1 | ForEach-Object {
        if ($header) {
            if ($_.StartsWith('@@ ')) { $header = $false }
        }
        else {
            $color = 'Cyan'
            if ($_.StartsWith('+')) {
                $color = 'Green'
            }
            elseif ($_.StartsWith('-')) {
                $color = 'Red'
            }
            Write-Host $_ -ForegroundColor $color
        }
    }
}

function CommitConfChanges([switch][bool]$force) {
    $newConfPath = Join-Path $bakPath 'web.new.config'
    $origConfPath = Join-Path $bakPath 'web.orig.config'
    $xmlDoc.Save($newConfPath)
    ShowDiff $origConfPath $newConfPath
    if ($force -or (Read-Host "確定要更新？Y/N") -ieq 'Y') {
        Copy-Item $newConfPath $configPath 
        Write-Host "已更新 $configPath" -ForegroundColor Cyan
        Stop-Transcript
    }
    else {
        Write-Host "放棄修改" -ForegroundColor Red
        Stop-Transcript
        . cmd.exe /c "rmdir $bakPath /s /q"
    }
}