Create a file for your Lambda function - Amazon CodeDeploy
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Create a file for your Lambda function

Create the file for the function you update and deploy later in this tutorial.


A Lambda function can use any runtime supported by Amazon Lambda. For more information, see Amazon Lambda runtimes.

To create your Lambda function

  1. Create a text file and save it as myDateTimeFunction.js in the SAM-Tutorial directory.

  2. Copy the following Node.js code into myDateTimeFunction.js.

    'use strict'; exports.handler = function(event, context, callback) { if (event.body) { event = JSON.parse(event.body); } var sc; // Status code var result = ""; // Response payload switch(event.option) { case "date": switch(event.period) { case "yesterday": result = setDateResult("yesterday"); sc = 200; break; case "today": result = setDateResult(); sc = 200; break; case "tomorrow": result = setDateResult("tomorrow"); sc = 200; break; default: result = { "error": "Must specify 'yesterday', 'today', or 'tomorrow'." }; sc = 400; break; } break; /* Later in this tutorial, you update this function by uncommenting this section. The framework created by Amazon SAM detects the update and triggers a deployment by CodeDeploy. The deployment shifts production traffic to the updated version of this function. case "time": var d = new Date(); var h = d.getHours(); var mi = d.getMinutes(); var s = d.getSeconds(); result = { "hour": h, "minute": mi, "second": s }; sc = 200; break; */ default: result = { "error": "Must specify 'date' or 'time'." }; sc = 400; break; } const response = { statusCode: sc, headers: { "Content-type": "application/json" }, body: JSON.stringify( result ) }; callback(null, response); function setDateResult(option) { var d = new Date(); // Today var mo; // Month var da; // Day var y; // Year switch(option) { case "yesterday": d.setDate(d.getDate() - 1); break; case "tomorrow": d.setDate(d.getDate() + 1); default: break; } mo = d.getMonth() + 1; // Months are zero offset (0-11) da = d.getDate(); y = d.getFullYear(); result = { "month": mo, "day": da, "year": y }; return result; } };

The Lambda function returns the day, month, and year for yesterday, today, or tomorrow. Later in this tutorial, you uncomment code that updates the function to return information about the day or time you specify (for example, the day, month, and year, or the current hour, minute, and second). The framework created by Amazon SAM detects and deploys the updated version of the function.


This Lambda function is also used in an Amazon Cloud9 tutorial. Amazon Cloud9 is a cloud-based integrated development environment. For information about how to create, execute, update, and debug this function in Amazon Cloud9, see Amazon Lambda tutorial for Amazon Cloud9.