azure - 如果没有数据，需要创建带标题的 Powershell 输出文件

Question

我创建了一个从 Azure 导出防火墙规则的脚本，它工作得很好，但是即使没有数据，我也需要创建带标题的 .csv。目前它正在创建一个空白文件。

``function create($path) {
    $exists = Test-Path -path $path
    Write-Host "tried the following path: $path, it" $(If ($exists) {"Exists"} Else {"Does not Exist!"}) 
    if (!($exists)) { New-Item $path -itemType Directory }
}

# reading file contents 
$subs_file =  "C:\script\Subscriptions.xlsx"
$azSubs = Import-Excel $subs_file
$azSubs
$output_folder = "C:\audit-automation"
# creating folder for outputing data 
create("$output_folder")
# New-Item $output_folder -itemType Directory

# iterating over subscriptions 
ForEach ( $sub in $azSubs ) {
    # sub
    $azsub = $sub.Subscription
    # app
    $app = $sub.Application
    $azsub
    $app
    # creating folder to save data for apps  
    # New-Item $output_folder\$app -itemType Directory
    # setting config for azure 
    Set-AzContext -SubscriptionName $azsub
        
    # FIREWALL RULES
    $azNsgs = Get-AzNetworkSecurityGroup
    # iterating over retrieved NSGs 
    $Output = ForEach ( $azNsg in $azNsgs ) {
        #Export custom rules
        Get-AzNetworkSecurityRuleConfig -NetworkSecurityGroup $azNsg | `
            Select-Object @{label = 'NSG Name'; expression = { $azNsg.Name } }, `
        @{label = 'NSG Location'; expression = { $azNsg.Location } }, `
        @{label = 'Rule Name'; expression = { $_.Name } }, `
        @{label = 'Source'; expression = { $_.SourceAddressPrefix } }, `
        @{label = 'Source Application Security Group'; expression = { $_.SourceApplicationSecurityGroups.id.Split('/')[-1] } },
        @{label = 'Source Port Range'; expression = { $_.SourcePortRange } }, Access, Priority, Direction, `
        @{label = 'Destination'; expression = { $_.DestinationAddressPrefix } }, `
        @{label = 'Destination Application Security Group'; expression = { $_.DestinationApplicationSecurityGroups.id.Split('/')[-1] } }, `
        @{label = 'Destination Port Range'; expression = { $_.DestinationPortRange } }, `
        @{label = 'Resource Group Name'; expression = { $azNsg.ResourceGroupName } },
        @{label = 'Subscription Name'; expression = { $azSub } } 
    }
    # creating folder to save 
    # New-Item $output_folder\$app\firewall_rules -itemType Directory
    create("$output_folder\$app")
    $Output | Export-Csv -Path $output_folder\$app\$app-firewall_rules_data$((Get-Date).ToString("yyyy-MM-dd")).csv -Append`

Answer 1

测试 $Output 变量是否包含任何内容 - 如果没有，则创建一个与实际输出对象形状相同的“虚拟对象”，并将其与 ConvertTo-Csv 生成 header :

# ...
create("$output_folder\$app")
$outputPath = "$output_folder\$app\$app-firewall_rules_data$((Get-Date).ToString("yyyy-MM-dd")).csv"

if($Output) {
    $Output | Export-Csv -Path $outputPath -Append -NoTypeInformation
}
elseif (-not(Test-Path $outputPath -PathType Leaf)) {
    # no output data, and the file doesn't already exist - create headers only
    $dummyObject = [pscustomobject]@{
        'NSG Name' = ''
        'NSG Location' = ''
        'Rule Name' = ''
        'Source' = ''
        'Source Application Security Group' = ''
        'Source Port Range' = ''
        'Destination' = ''
        'Destination Application Security Group' = ''
        'Destination Port Range' = ''
        'Resource Group Name' = ''
        'Subscription Name' = ''
    }

    # generate dummy CSV document, then discard the row representing the dummy object
    $header = $dummyObject |ConvertTo-Csv -NoTypeInformation |Select -SkipLast 1
    $header |Set-Content $outputPath

}