节点:等待函数完成后再执行process.exit

Question

我对节点很陌生。我已经写了一个执行telnet的脚本。如果telnet有效，我们会执行traceroute并正确退出(这是有效的(。当telnet不起作用时，我仍然会进行traceroute，并尝试以退出状态-1退出。这不起作用。traceroute未显示，进程.exet(1(出现得太早/没有等到traceroute的输出。

这是我的脚本(它是lambda(：

'use strict';
const Traceroute = require('nodejs-traceroute');
const isPortReachable = require('is-port-reachable');
console.log('Loading function');
process.env.PATH = `${process.env.PATH}:${process.env.LAMBDA_TASK_ROOT}/bin`;

async function doTraceroute() {
try {
const tracer = new Traceroute();
tracer
.on('pid', (pid) => {
console.log(`pid: ${pid}`);
})
.on('destination', (destination) => {
console.log(`destination: ${destination}`);
})
.on('hop', (hop) => {
console.log(`hop: ${JSON.stringify(hop)}`);
})
.on('close', (code) => {
console.log(`close: code ${code}`);
});

tracer.trace('100.216.125.9');
} catch (ex) {
console.log(ex);
}
}
exports.handler = (event, context, callback) => {
(async () => {
console.log('Is port 9092 reachable of MC Kafka host? True or False')
let output = await isPortReachable(9092, {host: '100.216.125.9'})
if (output) {
console.log('Telnet worked: do traceroute')
await doTraceroute();
} else {
console.log('Telnet failed: do traceroute')
await doTraceroute();
console.log("Exit with error")
process.exit(1)
}
})();
};

我该如何解决？telnet失败时的当前输出为：

START RequestId: 315b0ac5-09d7-4b72-8ff7-746b28241f79 Version: $LATEST
2020-11-09T07:25:07.841Z    315b0ac5-09d7-4b72-8ff7-746b28241f79    INFO    Is port 9092 reachable of MC Kafka host? True or False
2020-11-09T07:25:08.851Z    315b0ac5-09d7-4b72-8ff7-746b28241f79    INFO    Telnet failed: do traceroute
2020-11-09T07:25:08.909Z    315b0ac5-09d7-4b72-8ff7-746b28241f79    INFO    pid: 20
2020-11-09T07:25:08.910Z    315b0ac5-09d7-4b72-8ff7-746b28241f79    INFO    Exit with error
END RequestId: 315b0ac5-09d7-4b72-8ff7-746b28241f79
REPORT RequestId: 315b0ac5-09d7-4b72-8ff7-746b28241f79  Duration: 1150.28 ms    Billed Duration: 1200 ms    Memory Size: 128 MB Max Memory Used: 70 MB  Init Duration: 176.80 ms    
RequestId: 315b0ac5-09d7-4b72-8ff7-746b28241f79 Error: Runtime exited with error: exit status 1
Runtime.ExitError

而没有显示追踪路线。当telnet成功并且没有出口1时，将显示traceroute。

Answer 1

您可以将traceroute处理封装在promise中并等待此promise：

function doTraceroute() {
return new Promise((resolve, reject) => {
try {
const tracer = new Traceroute();
tracer
.on('pid', (pid) => {
console.log(`pid: ${pid}`);
})
.on('destination', (destination) => {
console.log(`destination: ${destination}`);
})
.on('hop', (hop) => {
console.log(`hop: ${JSON.stringify(hop)}`);
})
.on('close', (code) => {
console.log(`close: code ${code}`);
resolve();
});
tracer.trace('100.216.125.9');
} catch (ex) {
console.log(ex);
reject(ex);
}
});
}

然后，您可以await返回的承诺：

await doTraceroute();