NodeJs - Detect whether app is on AWS or local

Is there a way in NodeJs to detect whether it's currently running on an EC2 instance or whether it's being run locally? I have some functionality that changes based on where it's deployed. I can detect the IP address but I want something more dynamic, not tied to specific server configurations.

Answers 1

  • We could hit EC2 Metadata endpoint to determine EC2 instance or not.

    This curl woks only within an EC2 instance

    curl http://169.254.169.254/latest/meta-data/
    

    Library node-ec2-metadata exposes an easy to use method which calls this metadata service behind the scenes.

    var metadata = require("node-ec2-metadata");
    
    metadata.isEC2().then(function (onEC2) {
      console.log("Running on EC2? " + onEC2);
    });
    

    Point to keep in mind, straight from the docs(since they hit the HEAD url and timeout after 500ms):

    The initial call may take up to 500ms on a non-EC2 host, but the result is cached so subsequent calls provide a result immediately


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