AWS Lambda Functions That Dynamically Schedule Their Next Runtime https://www.aaronmedacco.com/blog/post/2017/01/15/aws-lambda-functions-that-dynamically-schedule-their-next-runtime
var AWS = require("aws-sdk");
exports.handler = function(event, context) {
var cloudwatchevents = new AWS.CloudWatchEvents();
var intervals = Array(3, 5, 7);
var nextInterval = intervals[Math.floor(Math.random()*intervals.length)];
var currentTime = new Date().getTime(); // UTC Time
var nextTime = dateAdd(currentTime, "minute", nextInterval);
var nextMinutes = nextTime.getMinutes();
var nextHours = nextTime.getHours();
// =================================
// DO YOUR WORK HERE
// =================================
var scheduleExpression = "cron(" + nextMinutes + " " + nextHours + " * * ? *)";
var params = {
Name: "Your CloudWatch Rule Name",
ScheduleExpression: scheduleExpression
};
cloudwatchevents.putRule(params, function(err, data) {
if (err) {
console.log(err, err.stack);
}
else {
console.log(data);
}
})
};
var dateAdd = function(date, interval, units) {
var ret = new Date(date); // don't change original date
switch(interval.toLowerCase()) {
case 'year' : ret.setFullYear(ret.getFullYear() + units); break;
case 'quarter': ret.setMonth(ret.getMonth() + 3*units); break;
case 'month' : ret.setMonth(ret.getMonth() + units); break;
case 'week' : ret.setDate(ret.getDate() + 7*units); break;
case 'day' : ret.setDate(ret.getDate() + units); break;
case 'hour' : ret.setTime(ret.getTime() + units*3600000); break;
case 'minute' : ret.setTime(ret.getTime() + units*60000); break;
case 'second' : ret.setTime(ret.getTime() + units*1000); break;
default : ret = undefined; break;
}
return ret;
}
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"events:PutRule"
],
"Resource": [
"*"
]
}
]
}