使用Azure Functions沿着Azure Blob Storage创建无服务器解决方案，用于将旧URL重定向到新URL。创建Azure Blob Storage帐户以存储新网站的静态内容。将静态文件上载到名为$web的容器中，这是用于在Azure Blob存储上托管静态网站的特殊容器。请确保在存储帐户的设置中启用静态网站托管。然后创建一个包含旧URL到新URL的Map的JSON文件。将此文件上载到Blob存储容器，以便Azure Function可以访问它。

{
  "/old-url-1": "/foo/new-url-1",
  "/old-url-2": "/foo/new-url-2",
  ...
}

在此函数中，您将读取包含URLMap的JSON文件，并根据传入的请求执行必要的重定向。

[FunctionName("UrlRedirect")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", Route = null)] HttpRequest req,
        ILogger log)
    {
        string oldPath = req.Path;
        Dictionary<string, string> mappings = await GetMappings();

        if (mappings.TryGetValue(oldPath, out string newPath))
        {
            return new RedirectResult($"https://www.example.com{newPath}", permanent: true);
        }
        else
        {
            return new NotFoundResult();
        }
    }

    private static async Task<Dictionary<string, string>> GetMappings()
    {
        string connectionString = "<your_connection_string>";
        BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString);
        BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient("$web");
        BlobClient blobClient = containerClient.GetBlobClient("mappings.json");

        using MemoryStream memoryStream = new MemoryStream();
        await blobClient.DownloadToAsync(memoryStream);
        memoryStream.Position = 0;

        using StreamReader reader = new StreamReader(memoryStream);
        string json = await reader.ReadToEndAsync();

        return JsonConvert.DeserializeObject<Dictionary<string, string>>(json);
    }

不要忘记更新旧域（www.example.com）的DNS设置foo.example.com，以指向Azure Functions App自定义域。