无法从lambda发布SNS主题

Question

我正在编写一个发布到SNS主题的lambda函数，但它在任何结果返回之前超时，这是我的函数：

var AWS = require('aws-sdk'); // Used for calling SNS
var pg = require ('pg'); // Used to connect to Postgre

exports.handler = function (event, context) {
  'use strict';
  // Step 1 call database to get school hours
  var conn = "postgres://OMITTED:OMITTED@sOMITTED.ap-southeast-2.rds.amazonaws.com/slm_appdb"; // Save this in env variable
  var client = new pg.Client(conn);
  client.connect();

  // Step 1 call the database to get the hours
  const query = client.query("select * from find_all_students_school_hours();", (err,res) => {
    console.info('Query made',res.rows);
    res.rows.forEach(function(row){

      var command = {
        username: row.username,
        commands: {
          working_days: row.working_days || 'Mon-Fri',
          school_start_time: row.school_start_time || '08:00:00', // Save this in env variable
          school_end_time: row.school_end_time || '17:00:00' // Save this in env variable
        }
      };

      // Step 2 add command for agent by calling another lambda function through SNS
      var sns = new AWS.SNS();
      var params = {
        Message: JSON.stringify(command),
        Subject: 'Agent School Hours',
        TopicArn: 'arn:aws:sns:ap-southeast-2:OMITTED:add-command-for-agent-topic'
      }
      console.log('params',params);
      sns.publish(params, function(err,snsres){
        if(err){
          console.error('error',err);
        } else {
          console.info('published to sns',snsres);
        }
      });
    });

    context.done();
  });
};

我已将此政策附加到lambda函数：

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": [
                "sns:*"
            ],
            "Effect": "Allow",
            "Resource": "*"
        }
    ]
}

我在日志中得到的是params数据，但之后没有任何内容，所以我从未到达console.error('error',err);或console.info('published to sns',snsres);，我给了它一分钟超时但仍然超时在它发布之前和日志中没有来自SNS的错误（见下图），有没有一种方法可以调试它以找出发生了什么？

Answer 1

您正在呼叫context.done()而不等待sns.publish完成。

请记住，Javascript是异步的，所以当您在sns.publish循环中执行I / O事件（res.rows.forEach()）时，context.done()将立即终止您的处理程序执行（并返回）等待你的SNS主题发表。