Serverless Workflows on AWS: My Journey From SWF to Step Functions

AWS Lambda functions can only run for a maximum of five minutes. This must be distinctly understood, or nothing wonderful can come of the story you are about to hear.

The Problem

This past summer, my team and I set out to build an internal software system used for deployment testing on AWS. The application would run a large number of workflow executions in parallel each night and might perform a few one-off executions during the day – maybe six hours total use out of every twenty-four, with only a small fraction of that time spent doing actual compute tasks. Trying to scale, manage and spend money on EC2 instances for that workload didn’t interest us. We wanted to run our whole workflow process end-to-end on AWS Lambda.

And we did. Heaven help us, we did. This is our story.

Continue reading “Serverless Workflows on AWS: My Journey From SWF to Step Functions”

Serverless Workflows on AWS: My Journey From SWF to Step Functions

Adventures in AWS: Understanding the Price List API

The AWS Price List API

In December 2015, AWS announced a new Price List API that exposes access to current prices for several of their products, including EC2 and RDS. If you’re thinking about building some automation to track AWS spend, and you’re used to working with AWS’s generally marvelous APIs and language SDKs, this sounds like great news. At least, that’s what I thought when I sat down last week to build a tool that would track cost savings for stopped EC2 instances in some of my company’s AWS environments.

Let’s just say the Price List API didn’t match my initial expectations. In fact, calling it an “API” is a bit generous; basically it’s a giant JSON or CSV file you can download for various AWS services that contains price and product data indexed by SKU.

What’s a SKU, you ask? The short answer is it’s a “Stock Keeping Unit“; the even shorter answer is that it doesn’t matter, because nowhere else in the AWS API ecosystem are SKUs for individual resources made available, so you’re not going to be cross-referencing them with anything else. But don’t despair; it is in fact possible to automate price lookups inside the AWS Price List data dump. Let me walk you through the approach I used.

Continue reading “Adventures in AWS: Understanding the Price List API”

Adventures in AWS: Understanding the Price List API

Lambda calculus: talking Serverless with Florian Motlik

The open source Serverless project, which currently has nearly 10,000 stars on Github, provides tooling around AWS’s “Function as a Service” ecosystem that includes Lambda and API Gateway. I recently had the opportunity to chat with Florian Motlik, CTO of Serverless, about his thoughts on serverless architectures and the future of the Serverless framework.

The following interview has been edited and condensed. 

Forrest: Although AWS Lambda is less than two years old, we’re already seeing a robust tooling ecosystem appear around it, including the Serverless Framework. How did the Serverless project get started?

HeadshotFlorian: Austen Collins, our founder, started Serverless about a year ago. In his previous life as a consultant, he worked with AWS Lambda while building various applications. Austen saw two things about Lambda that made a huge difference for him. First, it enables you to build applications without having to maintain infrastructure. And as someone who had to maintain infrastructure in the past, he saw that was a really interesting direction for the industry to go. Second, Lambda enables an event-driven architecture, where you just react to events that can be fired from anywhere to anywhere. Austen also saw that although Lambda was very powerful, its lack of tooling made it hard for new users to get started. So, about a year ago he started building the Serverless framework. The project took off right away, and towards the end of last year, he decided that this is not just an open source framework; it’s something we can build a company around. So that’s when I was brought on as the CTO to lead our engineering team, and we grew from there.

Continue reading “Lambda calculus: talking Serverless with Florian Motlik”

Lambda calculus: talking Serverless with Florian Motlik

Invoke Pester Tests Serverlessly with AWS Lambda and SSM

Pester and CI

If you’re doing Windows scripting in 2016, you’d better be using PowerShell. And if you’re writing PowerShell scripts, you’d better be checking them into source control and covering them with Pester tests.

It turns out that you can do more with Pester than just run tests manually at the console. As part of a continuous integration (CI) process, you may want to invoke Pester tests on a remote server and report the results up through the build chain. Handily, you can export Pester test output in an NUnit XML format that modern CI systems like Jenkins understand.

But what if you’re not using a build server to invoke Pester? What if your CI setup is … dun dun dun … “serverless”?

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Invoke Pester Tests Serverlessly with AWS Lambda and SSM

My AWS Lambda Cookbook

This cookbook is still in progress and will grow over time.

Lambda, AWS’s bite-size “serverless” compute service, is mostly awesome. However, it still has a relative lack of good documentation.

I’ve been using Lambda a lot lately, meaning I’ve had a lot of browser tabs open trying to find examples of the latest features like VPC support, Cloudformation integration and Python 2.7 functions. In this post, I’ll try to save you some time by sharing examples of a few things that have sent me searching.

Continue reading “My AWS Lambda Cookbook”

My AWS Lambda Cookbook

Could serverless computing work in a public volunteer cloud?

Serverless computing

What’s that old schoolyard rhyme? “AWS and Azure, sitting in a tree, I – A -A – S,  P – A -Y – G. First come VMs, then containers, then come stateless microservices running on public cloud infrastructure at fractions of a cent per second.” Or something like that.

Anyway, application deployments are getting lighter, backend microservices are getting smaller, and now many development shops are moving toward “serverless architectures” in which dynamic computational tasks are handled using a few cycles on somebody else’s managed server. As of 2016, the public cloud giants (AWS, Google Cloud and Microsoft Azure) all have their own “serverless services” that allow you to buy processing time for cheap. And I do mean cheap – a million AWS Lambda requests per month, each lasting five seconds, will set you back about $10.62.

Developers gravitate toward this approach because it’s scalable, cost-effective and requires little to no infrastructure maintenance. In AWS, you might deploy an application with data stores in RDS or DynamoDB, static web content hosted in S3, an API Gateway directing traffic and Lambda functions running the business rules – look Mom, no servers!

But wait a minute. Is a pay-as-you-go public cloud really the only place to run serverless compute functions? After all, a handful of computer scientists have been running little pieces of code on distributed computers for years, at a price even Lambda will never beat: free.

Continue reading “Could serverless computing work in a public volunteer cloud?”

Could serverless computing work in a public volunteer cloud?

Adventures in AWS: Error launching CloudFormation stacks in Powershell

This blog post definitely falls under the “Note to Self” category, because I’ve run into this issue like three times now, so here’s hoping that writing down the answer helps me (and maybe you too).

If you launch CloudFormation stacks through the AWS Powershell Tools with the New-CFNStack cmdlet, you may have run into this funky error from time to time:

 New-CFNStack: Object reference not set to an instance of an object.

This is not a helpful error message, and I’ve seen it mean a couple different things.

Reason 1 (most common): You’re missing a required template parameter

The New-CFNStack cmdlet takes an array of Amazon.CloudFormation.Model.Parameter key-value pairs as an argument to the “Parameters” parameter. If you try to put a null value in one of those parameter objects and your CloudFormation template doesn’t allow that parameter to be null, you’ll get the error specified above. This can be hard to debug because normally you’d expect a Powershell cmdlet to come back with an error message like “No argument was specified for parameter ‘X'” in such situation. Again, like I said, bad error message, but an easy fix.

Reason 2 (incredibly specific and stupid): You’re using an old version of the Powershell Tools with named credential profiles

Hopefully nobody else has run into this one. Recent versions of the Powershell Tools include a common parameter called “ProfileName”, which can be used to specify the name of an AWS access keypair saved in your .aws/credentials file or the SDK Store. The old “StoredCredentials” common parameter is still available for backwards compatibility. If you’re using a version of the Powershell Tools older than 2.1.9 (I think), the StoredCredentials parameter is all you get, but it doesn’t work too well with profiles saved in .aws/credentials instead of the SDK Store. In fact, I’ve gotten the “object reference” New-CFNStack error when trying to use named profiles with that cmdlet. Moral of the story: keep your AWS Tools up to date and you’ll never see this issue.

I’ll update this post if I find any other issues with this cmdlet. Thanks for reading!

Adventures in AWS: Error launching CloudFormation stacks in Powershell