aws-command-stack

aws-command-stack

This module helps in running complex series of dependent AWS API methods. There's not really any AWS specific logic here, it simply wraps the client objects provided by the AWS SDK and exposes an async stack interface for pushing named commands onto the stack, these can optionally include a callback that can in turn push more commands. Originally developed to support the specific use case of creating/viewing/destroying VPCs and their dependents (Internet Gateways, Subnets, NAT instances, etc.), see [list-clouds.js] for a related example.

Install

npm install aws-command-stack

Example

Find and release all of the unallocated VPC Elastic IP addresses in a region.

var AWSCommandStack = require("aws-command-stack");

// configure clients (can be avoided with IAM Roles for EC2 Instances)
var config = {
   region: 'us-east-1',
   accessKeyId: 'AKyourAccessKeyId',
   secretAccessKey: 'yourSecretAccessKey'
};

// create the stack, first argument is a list of which API clients to initialize 
var aws = new AWSCommandStack(['EC2'], config);

aws.on("error", function (error) { console.error(error); process.exit(1); });

// push our first command, with a custom call back
aws.push("EC2.describeAddresses", { Filters: [ { Name: "domain", Values: [ "vpc" ] } ] }, function (data) {
  var Addresses = data.Addresses.filter(function (Address) { return !Address.InstanceId; });
  Addresses.forEach(function (Address) {
    // push our followup commands, these use the default callback
    aws.push("EC2.releaseAddress", { AllocationId: Address.AllocationId });
  });
  aws.next(); // tells stack to go on to the next command, or exit if all done
});

// push our first command
aws.run();

You can use the included sample list-clouds.js to view a hierarchal list of all VPCs in a region (including subnets and instances):

% node list-clouds.js us-west-2
us-west-2: found 1 Vpcs
  vpc-71cbe109        10.0.0.0/16 []
    subnet-79cbe110   10.0.1.0/24
    subnet-7adbe112   10.0.0.0/24
      i-ea57cefd      10.0.0.162   54.213.18.102 []

License

MIT

Changes

• 0.2.0
  • simplified error handling, all callbacks will emit error params as error event on the stack object
  • collapsed run/done into single next call