Product Guy, Serverless Advocate & Startup Veteran

My name is Jeremy Daly. I appreciate the visit. 👍 I’ve been managing the development of complex web and mobile applications for businesses across the globe for over 20 years. I’m currently the Chief Technology Officer at AlertMe, but I always keep myself busy with several side projects and consulting clients.

I write a lot about serverless and I like to share thoughts and stories about programmingproduct managemententrepreneurship and productivity. Sometimes I’ll write reviews or have random thoughts that I need to get out of my head. I also like to post a how-to article every once in a while. Feel free to jump in to one of the categories above, view all my posts, or view my latest posts below.

If you’d like to get updates, please sign up for my mailing list or follow me on Twitter and Github.


My Latest Posts:

How-To: Tag Your Lambda Functions for Smarter Serverless Applications

As our serverless applications start to grow in complexity and scope, we often find ourselves publishing dozens if not hundreds of functions to handle our expanding workloads. It’s no secret that serverless development workflows have been a challenge for a lot of organizations. Some best practices are starting to emerge, but many development teams are simply mixing their existing workflows with frameworks like Serverless and AWS SAM to build, test and deploy their serverless applications.

Beyond workflows, another challenge serverless developers encounter as their applications expand, is simply trying to keep all of their functions organized. You may have several functions and resources as part of a microservice contained in their own git repo. Or you might simply put all your functions in a single repository for better common library sharing. Regardless of how code is organized locally, much of that is lost when all your functions end up in a big long list in the AWS Lambda console. In this post we’ll look at how we can use AWS’s resource tagging as a way to apply structure to our deployed functions. This not only give us more insight into our applications, but can be used to apply Cost-Allocation Tags to our billing reports as well. 👍

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Thinking Serverless (Big and Small)

I’ve been reading and writing a lot of about serverless lately, and one of the things I realized, is that most articles talk about how SCALABLE serverless architectures are. This, of course, is one of the major benefits of using serverless to build your applications. The ability to scale to thousands of concurrent requests per second without needing to manage your own servers, is simply amazing. 🙌

However, not needing to manage any servers has other benefits beyond the capabilities to achieve web scale. Having on-demand compute space also make serverless the perfect candidate for smaller workloads. In this post, let’s discuss how we can utilize serverless to handle our “less than unicorn 🦄” services and the benefits this can bring.

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Lambda Warmer: Optimize AWS Lambda Function Cold Starts

At a recent AWS Startup Day event in Boston, MA, Chris Munns, the Senior Developer Advocate for Serverless at AWS, discussed Lambda cold starts and how to mitigate them. According to Chris (although he acknowledge that it is a “hack”) using the CloudWatch Events “ping” method is really the only way to do it right now. He gave a number of really good tips to pre-warm your functions “correctly”:

  • Don’t ping more often than every 5 minutes
  • Invoke the function directly (i.e. don’t use API Gateway to invoke it)
  • Pass in a test payload that can be identified as such
  • Create handler logic that replies accordingly without running the whole function

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15 Key Takeaways from the Serverless Talk at AWS Startup Day

I love learning about the capabilities of AWS Lambda functions, and typically consume any article or piece of documentation I come across on the subject. When I heard that Chris Munns, Senior Developer Advocate for Serverless at AWS, was going to be speaking at AWS Startup Day in Boston, I was excited. I was able to attend his talk, The Best Practices and Hard Lessons Learned of Serverless Applications, and it was well worth it.

Chris said during his talk that all of the information he presented is on the AWS Serverless site. However, there is A LOT of information out there, so it was nice to have him consolidate it down for us into a 45 minute talk. There was some really insightful information shared and lots of great questions. I was aware of many of the topics discussed, but there were several clarifications and explanations (especially around the inner workings of Lambda) that were really helpful. 👍

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Mixing VPC and Non-VPC Lambda Functions for Higher Performing Microservices

I came across a post the in the Serverless forums that asked how to disable the VPC for a single function within a Serverless project. This got me thinking about how other people structure their serverless microservices, so I wanted to throw out some ideas. I often mix my Lambda functions between VPC and non-VPC depending on their use and data requirements. In this post, I’ll outline some ways you can structure your Lambda microservices to isolate services, make execution faster, and maybe even save you some money. ⚡️💰

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5 Reasons Why Your Serverless Application Might Be A Security Risk

There has been a lot of buzz lately about serverless security. People are certainly talking about it more and sharing great articles on the topic, but many serverless developers (especially new ones) are still making the same critical mistakes. Every time a serverless function is deployed, its unique security challenges need to be addressed. Every time. I’ve researched and written extensively about serverless security (see Securing Serverless: A Newbie’s Guide). I’ve read countless articles on the subject. And while there is no shortage of information available, let’s be honest: developers are busy building applications, not pouring through hundreds of articles.

I know, it sounds boring, but I would encourage you to do your research on serverless security. Serverless applications are different than traditional, server-hosted applications. Much of the security responsibility falls on the developer, and not following best practices opens you (or your company) up to an attack. But I know you’re busy. I totally get it. So rather than forcing you to read a bunch of long articles 😴 or watch a plethora of videos 🙈, I’ve whittled it all down to the five biggest serverless security risks for you. Sure, there are a lot of other things to consider, but IMO, these are the most important ones. Nothing here hasn’t been said before. But If you do nothing more than follow these principles, your serverless applications will be much more secure. 🔒

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Serverless Consumers with Lambda and SQS Triggers

On Wednesday, June 27, 2018, Amazon Web Services released SQS triggers for Lambda functions. Those of you who have been building serverless applications with AWS Lambda probably know how big of a deal this is. Until now, the AWS Simple Queue Service (SQS) was generally a pain to deal with for serverless applications. Communicating with SQS is simple and straightforward, but there was no way to automatically consume messages without implementing a series of hacks. In general, these hacks “worked” and were fairly manageable. However, as your services became more complex, dealing with concurrency and managing fan out made your applications brittle and error prone. SQS triggers solve all of these problems. 👊

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Event Injection: A New Serverless Attack Vector

As more and more developers and companies adopt serverless architecture, the likelihood of hackers exploiting these applications increases dramatically. The shared security model of cloud providers extends much further with serverless offerings, but application security is still the developer’s responsibility. There has been a lot of hype about #NoOPS with serverless environments 🤥, which is simply not true 😡. Many traditional applications are frontended with WAFs (web application firewalls), RASPs (runtime application self-protection), EPPs (endpoint protection platforms) and WSGs (web security gateways) that inspect incoming and outgoing traffic. These extra layers of protection can save developers from themselves when making common programming mistakes that would otherwise leave their applications vulnerable. With serverless, these all go away. 😳

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10 Things You Need To Know When Building Serverless Applications

I am a HUGE fan of serverless architectures. This new type of compute not only opens up more possibilities for developers, but can support highly-scalable, complex applications for a fraction of the cost compared to provisioning virtual servers. My first question when planning a new application is always, “Can I build this with serverless?” Spoiler alert, the answer is almost always YES!

I’ve been building serverless applications since the release of AWS Lambda in 2015, so answering the question above is pretty easy for me. However, a lot of people I talk to who are new to serverless often have many questions (and misconceptions). I want you to be successful, so below I’ve create a list of 10 things you need to know when building a serverless application. These are things I wish I knew when I started, so hopefully they’ll help you get up to speed a faster and start building some amazing applications.

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🚀 Project Update:

Lambda API: v0.7 Released

v0.7 adds new features to control middleware execution based on path, plus additional parsing of the AWS Lambda context object. ESLint and coverage reports using Istanbul and Coveralls were also added to ensure code quality and adequate test coverage. Read More...

How To: Optimize the Serverless Optimizer Plugin

I’m sure you’re already well aware of how awesome the ⚡ Serverless Framework is for managing and deploying your serverless applications. And you’re probably aware that there are several great plugins available that make Serverless even better. But did you know that there was a plugin to optimize your functions and reduce the size of your deployment packages? Or are you already using this plugin to optimize your functions, but hate how it takes too long to optimize locally run functions? In this post I’ll share some quick tips to help you optimize your Serverless Optimizer experience.

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Transducers: Supercharge your functional JavaScript

This is the first in a series of posts on functional programming in JavaScript. My goal is to make these ideas more accessible to all levels of programmers. Feedback about style, content, etc., would all be greatly appreciated.

One thing that perplexed me early on in my functional programming days was the concept of transducers. I spent a lot of time Googling and found some great articles that went deep into the theory and the underlying mechanics. However, the practical use of them still seemed a bit out of reach. In this post I’ll attempt to explain transducers in a more understandable way and hopefully give you the confidence to use them in your functional JavaScript. While this article attempts to make transducers more accessible, you will need to have some basic knowledge of functional programming in JavaScript. Specifically, you should know about function composition and iterator functions like .map(), .filter(), and most importantly, .reduce(). If you are unfamiliar with these concepts, go get a grasp on them first.

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🚀 Project Update:

Lambda API: v0.6 Released

v0.6 is all about making the serverless developer's life easier! New support for both callback-style and async-await in route functions and middleware, new HTTP method routing features, and route debugging tools. Plus Etag support and automatic authorization parsing. Read More...

Solving the Cold Start Problem

Dear AWS Lambda Team,

I have a serious problem: I love AWS Lambda! In fact, I love it so much that I’ve pretty much gone all in on this whole #serverless thing. I use Lambda for almost everything now. I use it to build backend data processing pipelines, distribute long running tasks, and respond to API requests. Heck, I even built an Alexa app just for fun. I found myself building so many RESTful APIs using Lambda and API Gateway that I went ahead and created the open source Lambda API web framework to allow users to more efficiently route and respond to API Gateway requests.

Serverless technologies, like Lambda, have revolutionized how developers think about building applications. Abstracting away the underlying compute layer and replacing it with on-demand, near-infinitely scalable function containers is brilliant. As we would say out here in Boston, “you guys are wicked smaht.” But I think you missed something very important. In your efforts to conform to the “pay only for the compute time you consume” promise of serverless, you inadvertently handicapped the service. My biggest complaint, and the number one objection that I hear from most of the “serverless-is-not-ready-for-primetime” naysayers, are Cold Starts.

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How To: Manage Serverless Environment Variables Per Stage

I often find myself creating four separate stages for each ⚡ Serverless Framework project I work on: dev, staging, prod, and local. Obviously the first three are meant to be deployed to the cloud, but the last one, local, is meant to run and test interactions with local resources. It’s also great to have an offline version (like when you’re on a plane ✈ or have terrible wifi somewhere). Plus, development is much faster because you’re not waiting for round trips to the server. 😉

A really great feature of Serverless is the ability to configure ENVIRONMENT variables in the serverless.yml file. This lets us store important global information like database names, service endpoints and more. We can even reference passwords securely using AWS’s Service Manager Parameter Store and decode encrypted secrets on deployment, keeping them safe from developers and source repositories alike. 😬 Just reference the variable with ${ssm:/myapp/my-secure-value~true} in your configuration file.

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🚀 Project Update:

Lambda API: v0.5 Released

v0.5 takes advantage of AWS Lambda's recently released support for Node v8.10 and has removed its Bluebird promise dependency in favor of async/await. Lambda API is now faster and adds built-in CORS support, additional wildcard features, new HTTP header management methods and more. Read More...

How To: Stub “.promise()” in AWS-SDK Node.js

Since AWS released support for Node v8.10 in Lambda, I was able to refactor Lambda API to use async/await instead of Bluebird promises. The code is not only much cleaner now, but I was able to remove a lot of unnecessary overhead as well. As part of the refactoring, I decided to use AWS-SDK’s native promise implementation by appending .promise() to the end of an S3 getObject call. This works perfectly in production and the code is super compact and simple:

The issue came with stubbing the call using Sinon.js. With the old promise method, I was using promisifyAll() to wrap new AWS.S3() and then stubbing the getObjectAsync method. If you’re not familiar with stubbing AWS services, read my post: How To: Stub AWS Services in Lambda Functions using Serverless, Sinon.JS and Promises.

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How To: Manage RDS Connections from AWS Lambda Serverless Functions

Someone asked a great question on my How To: Reuse Database Connections in AWS Lambda post about how to end the unused connections left over by expired Lambda functions:

I’m playing around with AWS lambda and connections to an RDS database and am finding that for the containers that are not reused the connection remains. I found before that sometimes the connections would just die eventually. I was wondering, is there some way to manage and/or end the connections without needing to wait for them to end on their own? The main issue I’m worried about is that these unused connections would remain for an excessive amount of time and prevent new connections that will actually be used from being made due to the limit on the number of connections.

🧟‍♂️ Zombie RDS connections leftover on container expiration can become a problem when you start to reach a high number of concurrent Lambda executions. My guess is that this is why AWS is launching Aurora Serverless, to deal with relational databases at scale. At the time of this writing it is still in preview mode. 😧

Overall, I’ve found that Lambda is pretty good about closing database connections when the container expires, but even if it does it reliably, it still doesn’t solve the MAX CONNECTIONS problem. Here are a few strategies that I’ve used to deal with this issue.

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Is Code Really Self-Documenting?

In my 20+ years of programming, I’ve encountered a near endless amount of opinions on everything from coding styles to programming paradigms to the great whitespace debate. Obviously, I have strong opinions on a number of these. But for me, the one that bothers me the most is this notion that “code is self-documenting.” 😾

I know what you’re probably thinking: “of course not all code is self-documenting, only well-written code is.” I don’t entirely disagree. I can generally look at someone else’s code and understand exactly WHAT it is doing. However, often it’s not obvious WHY they did it that way, or even why they did it in the first place. In my opinion, the programmer’s intent (the WHY) is just as important as the HOW when it comes to properly documenting software.

So whether you agree with me or not, let’s explore how to better document our software by writing cleaner code, following some general commenting etiquette, and commenting more effectively to make you and your team more productive. 👍

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Securing Serverless: A Newbie’s Guide

So you’ve decided to build a serverless application. That’s awesome! May I be the first to welcome you to the future. 🤖 I bet you’ve done a lot of research. You’ve probably even deployed a few test functions to AWS Lambda or Google Cloud Functions and you’re ready to actually build something useful. You probably still have a bunch of unanswered questions, and that’s cool. We can still build some really great applications even if we only know the basics. However, when we start working with new things we typically make a bunch of dumb mistakes. While some are relatively innocuous, security mistakes can cause some serious damage.

I’ve been working with serverless applications since AWS launched Lambda in early 2015. Over the last few years I’ve developed many serverless applications covering a wide range of use cases. The most important thing I’ve learned: SECURE YOUR FUNCTIONS! I can tell you from personal experience, getting burned by an attack is no bueno. I’d hate to see it happen to you. 😢

To make sure it doesn’t happen to you, I’ve put together a list of 🔒Serverless Security Best Practices. This is not a comprehensive list, but it covers the things you ABSOLUTELY must do. I also give you some more things to think about as you continue on your serverless journey. 🚀

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How To: Build a Serverless API with Serverless, AWS Lambda and Lambda API

AWS Lambda and AWS API Gateway have made creating serverless APIs extremely easy. Developers can simply create Lambda functions, configure an API Gateway, and start responding to RESTful endpoint calls. While this all seems pretty straightforward on the surface, there are plenty of pitfalls that can make working with these services frustrating.

There are, for example, lots of confusing and conflicting configurations in API Gateway.  Managing deployments and resources can be tricky, especially when publishing to multiple stages (e.g. dev, staging, prod, etc.). Even structuring your application code and dependencies can be difficult to wrap your head around when working with multiple functions.

In this post I’m going to show you how to setup and deploy a serverless API using the Serverless framework and Lambda API, a lightweight web framework for your serverless applications using AWS Lambda and API Gateway. We’ll create some sample routes, handle CORS, and discuss managing authentication. Let’s get started.

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