AWS Node.js SDK; EC2 instance creation and termination example

ec2.js

var aws = require('aws-sdk');

aws.config.update({
    accessKeyId: 'YOUR_ACCESS_KEY', 
    secretAccessKey: 'YOUR_SECRET_KEY', 
    region: 'us-west-2'
});

var ec2 = new aws.EC2();

function printStatuses() {
    ec2.describeInstances({}, function(err, data) {
        if(err) {
            console.error(err.toString());
        } else {
            var currentTime = new Date();
            console.log(currentTime.toString());

            for(var r=0,rlen=data.Reservations.length; r<rlen; r++) {
                var reservation = data.Reservations[r];
                for(var i=0,ilen=reservation.Instances.length; i<ilen; ++i) {
                    var instance = reservation.Instances[i];

                    var name = '';
                    for(var t=0,tlen=instance.Tags.length; t<tlen; ++t) {
                        if(instance.Tags[t].Key === 'Name') {
                            name = instance.Tags[t].Value;
                        }
                    }
                    console.log('\t'+name+'\t'+instance.InstanceId+'\t'+instance.PublicIpAddress+'\t'+instance.InstanceType+'\t'+instance.ImageId+'\t'+instance.State.Name);
                }
            }
        }
    });    
}

function createInstance(imageId, count, keyPair, securityGroup, instanceType) {
    ec2.runInstances({
        ImageId: imageId,
        MinCount: count,
        MaxCount: count,
        KeyName: keyPair,
        SecurityGroups: [securityGroup],
        InstanceType: instanceType
    }, function(err, data) {
        if(err) {
            console.error(err.toString());
        } else {
            for(var i in data.Instances) {
                var instance = data.Instances[i];
                console.log('NEW:\t' + instance.InstanceId);
            }
        }
    });
}

function terminateInstance(instanceId) {
    ec2.terminateInstances({ InstanceIds: [instanceId] }, function(err, data) {
        if(err) {
            console.error(err.toString());
        } else {
           for(var i in data.TerminatingInstances) {
                var instance = data.TerminatingInstances[i];
                console.log('TERM:\t' + instance.InstanceId);
            } 
        }
    });
}