请求编写PowerShell脚本：批量替换多服务器指定文件中的主机FQDN

Got it, let's turn that single-server script into a multi-machine powerhouse! Here's a robust, scalable solution that'll let you batch-update the FQDN in your target file across multiple remote servers, with built-in error handling to keep things smooth.

Prerequisites #

Before diving in, make sure you have these covered:

• Administrator (or file-modification) permissions on all target servers
• WinRM enabled and configured on remote servers (most domain environments have this by default; for workgroups, you may need to run Enable-PSRemoting -Force on each server first)
• Either a list of custom FQDNs per server, or the ability to auto-fetch each server's actual FQDN

The Complete Script #

This script supports both custom FQDN mappings and auto-generated ones, plus clear success/failure reporting:

# Define your target servers - load from a text file with Get-Content if preferred
$targetServers = @("Server01", "Server02", "Server03", "Server04")

# Full path to the file you need to modify on remote servers
$targetFilePath = "C:\AppConfig\config.json" # Adjust this to your actual file path

# Optional: Use this hashtable if you need custom FQDNs per server (skip if using auto-fetched FQDNs)
$customFqdns = @{
    "Server01" = "server01.prod.yourdomain.com"
    "Server02" = "server02.prod.yourdomain.com"
    # Add more server-FQDN pairs as needed
}

# Pattern to match the old FQDN in the file - use regex for dynamic matches (e.g., '\b[A-Za-z0-9.-]+\.[A-Za-z]{2,}\b' for any FQDN)
$oldFqdnPattern = "legacy-fqdn.yourdomain.com" # Replace with your actual old string/pattern

# Execute the batch replacement
Invoke-Command -ComputerName $targetServers -ScriptBlock {
    param(
        [string]$FilePath,
        [string]$OldPattern,
        [string]$NewFqdn
    )

    try {
        # Validate file exists before proceeding
        if (-not (Test-Path -Path $FilePath -PathType Leaf)) {
            throw "Target file not found at $FilePath"
        }

        # Read file content as a single string (preserves line breaks)
        $fileContent = Get-Content -Path $FilePath -Raw -ErrorAction Stop

        # Replace the old FQDN pattern with the new one
        $updatedContent = $fileContent -replace $OldPattern, $NewFqdn

        # Write changes back to the file
        Set-Content -Path $FilePath -Value $updatedContent -ErrorAction Stop

        Write-Host "✅ Successfully updated FQDN on $env:COMPUTERNAME"
    }
    catch {
        Write-Error "❌ Failed to update $env:COMPUTERNAME : $_"
    }
} -ArgumentList $targetFilePath, $oldFqdnPattern, $(
    # Use custom FQDN if defined, else auto-fetch the server's actual FQDN
    if ($customFqdns.ContainsKey($using:PSItem)) {
        $customFqdns[$using:PSItem]
    }
    else {
        [System.Net.Dns]::GetHostEntry($using:PSItem).HostName
    }
)

Key Features Breakdown #

• Flexible Server Input: Swap the hardcoded $targetServers with Get-Content -Path "C:\Servers\prod_servers.txt" to load servers from a text file, or use Import-Csv for CSV lists
• Dual FQDN Mode: Use the $customFqdns hashtable for manual mappings, or omit it to auto-pull each server's real FQDN via DNS
• Safety & Visibility: Checks for file existence before making changes, and outputs clear success/error messages per server
• Efficient Remote Execution: Uses Invoke-Command to run the logic directly on each remote server, avoiding unnecessary file transfers

Critical Tips for Testing & Safety #

• Test First: Add -WhatIf to the Set-Content line (e.g., Set-Content -Path $FilePath -Value $updatedContent -WhatIf) to simulate changes without writing to the file
• Elevated Session: Run the script in an elevated PowerShell window (Right-click > Run as Administrator) to avoid permission issues
• Regex Tweaks: If your old FQDN varies per server, use the regex pattern '\b[A-Za-z0-9.-]+\.[A-Za-z]{2,}\b' to match any valid FQDN in the file

内容的提问来源于stack exchange，提问作者Karthik Kumar