dgram.createSocket(options[, callback])

• options <Object> 可用的选项有：
  • type <string> 套接字家族。 必须是 'udp4' 或 'udp6'。 必需的。
  • reuseAddr <boolean> 当 true socket.bind() 将重用该地址时，即使另一个进程已经在其上绑定了套接字。 默认值: false。
  • ipv6Only <boolean> 将 ipv6Only 设置为 true 将禁用双栈支持，即绑定到地址 :: 不会使 0.0.0.0 被绑定。 默认值: false。
  • recvBufferSize <number> 设置 SO_RCVBUF 套接字值。
  • sendBufferSize <number> 设置 SO_SNDBUF 套接字值。
  • lookup <Function> 自定义查找函数。 默认值: dns.lookup().
  • signal <AbortSignal> 可用于关闭套接字的中止信号。
• callback <Function> 绑定作为 'message' 事件的监听器。 可选的。
• 返回: <dgram.Socket>

创建 dgram.Socket 对象。 一旦创建了套接字，则调用 socket.bind() 将指示套接字开始监听数据报消息。 当 address 和 port 没有传给 socket.bind() 时，则该方法会将套接字绑定到随机端口上的“所有接口”地址（它对 udp4 和 udp6 套接字都做正确的事情）。 可以使用 socket.address().address 和 socket.address().port 检索绑定的地址和端口。

如果启用了 signal 选项，则在对应的 AbortController 上调用 .abort() 与在套接字上调用 .close() 类似：

const controller = new AbortController();
const { signal } = controller;
const server = dgram.createSocket({ type: 'udp4', signal });
server.on('message', (msg, rinfo) => {
  console.log(`server got: ${msg} from ${rinfo.address}:${rinfo.port}`);
});
// 稍后，当要关闭服务器时。
controller.abort();

• options <Object> Available options are:
  • type <string> The family of socket. Must be either 'udp4' or 'udp6'. Required.
  • reuseAddr <boolean> When true socket.bind() will reuse the address, even if another process has already bound a socket on it. Default: false.
  • ipv6Only <boolean> Setting ipv6Only to true will disable dual-stack support, i.e., binding to address :: won't make 0.0.0.0 be bound. Default: false.
  • recvBufferSize <number> Sets the SO_RCVBUF socket value.
  • sendBufferSize <number> Sets the SO_SNDBUF socket value.
  • lookup <Function> Custom lookup function. Default: dns.lookup().
  • signal <AbortSignal> An AbortSignal that may be used to close a socket.
• callback <Function> Attached as a listener for 'message' events. Optional.
• Returns: <dgram.Socket>

Creates a dgram.Socket object. Once the socket is created, calling socket.bind() will instruct the socket to begin listening for datagram messages. When address and port are not passed to socket.bind() the method will bind the socket to the "all interfaces" address on a random port (it does the right thing for both udp4 and udp6 sockets). The bound address and port can be retrieved using socket.address().address and socket.address().port.

If the signal option is enabled, calling .abort() on the corresponding AbortController is similar to calling .close() on the socket:

const controller = new AbortController();
const { signal } = controller;
const server = dgram.createSocket({ type: 'udp4', signal });
server.on('message', (msg, rinfo) => {
  console.log(`server got: ${msg} from ${rinfo.address}:${rinfo.port}`);
});
// Later, when you want to close the server.
controller.abort();