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All right, so I'm going to get started. This is Jets, a Ruby serverless framework. I'm going to talk about a tool I created.
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As is traditional, the first slide is an introductory slide: who I am and what I do. My name is Tung Nguyen, and I currently run a consultancy company called Bull Ops.
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You can see the logo up there in the top left corner. We focus on device software and infrastructure.
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I have been fortunate enough to create a variety of tools, which are represented by the icons you see on the slide.
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These tools range from Elastic Beanstalk to CloudFormation and ECS deployment, to name just a few.
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It was quite an honor to be recognized as a container hero by AWS, as there were only five of us in the world in that category.
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But today, we're going to focus on Jets, the Ruby serverless framework. One thing I'd like to point out is that, having worked extensively in the container space, I have a good appreciation for when to use containers versus serverless technology.
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Now, the reason we're here today is because in November 2018, AWS officially released Ruby support as a runtime for Lambda.
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This was a significant deal because, prior to this, Ruby was not an official runtime and developers had to bolt on support themselves.
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This update placed Ruby among the first-class citizens in the serverless world. For me, it felt like a Christmas present. I even took a picture at re:Invent in front of the big stage, and I literally screamed when they made the announcement.
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This kind of excitement for the Ruby community felt like the release of a new version of Ruby back in December.
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For me, this was very big news.
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I thought a good way to introduce the serverless world to this group would be to talk about some essential aspects of AWS and the compute offerings that exist today.
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On the left side is EC2, which is a regular virtual machine that you can spin up. It takes about two to three minutes to set up.
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You press a couple of buttons or call an API to create a machine, and then you can install anything you want on it and manage that server yourself.
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As you move from left to right in the offerings, the level of management you have to do decreases.
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ECS, or Elastic Container Service, allows you to run Docker containers easily on EC2 instances.
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You don't have to manage much yourself, and on the far right, we have AWS Lambda.
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That's what we'll focus on today. What is AWS Lambda? I put quotes around 'serverless' and a happy face because people call it serverless.
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The term became very popular, but I think it's a bit misleading because, in order to run serverless technology, you actually need servers, so it’s somewhat of an oxymoron.
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One definition you can think of is that it's functions as a service.
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Essentially, it allows you to run code without managing servers; you give AWS your code, and they handle how to run it.
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There are some benefits to using AWS Lambda. One major benefit is that you don't have to manage servers yourself; you don't have to do system upgrades or worry about security updates.
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A team of AWS engineers handles all of that for you. You can focus solely on your code.
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It scales on demand, depending on how many requests you send it. When EC2 introduced auto-scaling, I thought that was a remarkable feat of engineering.
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You just configure some auto-scaling policies, set some alarms and rules, and then your system can automatically scale up and down.
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With serverless technology, that scaling occurs automatically. You don’t have to configure anything; it just happens seamlessly.
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Another benefit is that you only pay for requests. With AWS Lambda, the pricing model is particularly interesting: you only pay for the requests you send.
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If you fit within the free tier, which is about a million requests a month, you can run your code for free.
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That's a pretty appealing model. Of course, there’s also a lot of hype surrounding serverless and its benefits.
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However, let’s address some of the hype. The term 'serverless' can be misleading at times.
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Now, let’s talk about some considerations and limitations regarding why serverless might not always be the best fit.
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When you configure a Lambda function, you allocate between 128 megabytes of RAM and up to 10 gigabytes.
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A typical Ruby process, say a Puma server, usually requires about 500 megabytes. If you multiply that by the number of threads, that creates another concern.
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But with Lambda’s self-scaling technology, you're not managing threads; it self-scales based on allocations.
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Your main concern is making sure your Ruby process does not consume more than three gigabytes.
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If you do have a Ruby process consuming more, you're likely encountering other issues.
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Now, looking at CPU, the processing power you get correlates directly to the memory you allocate.
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The more RAM you allocate, the more CPU power you gain. At around 1.5 gigabytes, you can get multi-core support.
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Most applications use memory-bound resources within Ruby, so CPU usually isn’t a bottleneck unless you're doing specialized tasks.
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Another consideration is the network speed. If there’s an issue here, you may notice slower performance.
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Now, let’s discuss duration limits. The maximum time a Lambda function can run has been increased to 15 minutes.
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For web applications, if your users are waiting for a response for 15 minutes, they’re likely long gone.
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So unless you're running a long-running process, this is not really a concern.
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Now, another consideration specifically for Ruby projects involves storage constraints. Your application can occupy up to 250 megabytes on the runtime file system.
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This includes libraries and dependencies. If your total dependencies are, say, 100 megabytes, that leaves you with only 150 megabytes for application code.
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This can indeed be a constraint, and something to monitor closely.
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It’s possible that AWS might increase this limit in the future as they continue to improve services.
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Next, let’s talk about the so-called cold start issue.
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When a request comes to AWS Lambda, a container spins up.
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There’s an overhead penalty associated with the first invocation of a lambda function.
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If you are using a minimal allocation, say 128 megabytes, the penalty could range from one to two seconds.
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However, if you're using a more realistic amount of memory, like one and a half gigabytes, I've seen it take around 300 milliseconds for the cold start.
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People often overemphasize this issue, but it reminds me of Rails' Russian Doll caching.
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The initial request may have slower response times, but subsequent requests are much quicker.
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In most cases, unless you are building large-scale applications, the cold start shouldn’t be a large concern.
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Functions can be reused for a period of time; I've noticed that they stay warm for four or five hours.
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To minimize this cold start issue, developers often use what is known as pre-warming.
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One common pattern involves creating a Lambda function that periodically calls all your other Lambda functions with a dummy payload.
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This approach helps to keep them warm, eliminating the cold start penalty.
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Now, there’s more to serverless than just functions. Another component is API Gateway.
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With API Gateway, you can think of it as a front door where users send requests.
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API Gateway routes these requests to different Lambda functions.
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When building RESTful APIs, the API Gateway becomes essential.
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Users make requests via URL, and that gets sent to the associated Lambda functions.
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These functions return responses through API Gateway, making it easy to build web APIs.
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In addition to API Gateway, there's CloudWatch, which features various functions, including scheduled events.
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Scheduled events allow you to call Lambda functions periodically.
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At this point, let’s take a look at the essential components of the service.
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Lambda acts as functions-as-a-service, API Gateway handles requests, and CloudWatch provides scheduled events and logging.
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With all these components, you can build a substantial web API architecture entirely serverless.
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Users access the API via endpoints, which then trigger Lambda functions to execute the necessary logic.
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These Lambda functions can interact with backend storage, such as DynamoDB or RDS.
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At the bottom are the CloudWatch events that trigger background jobs.
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Next, let’s look at some actual serverless code.
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One way to create functions is through the AWS Management Console.
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You would click on the 'Create Function' button, assign a name, choose Ruby as the runtime, and create the function.
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You’ll then be directed to the code editor, where you can write your application logic.
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In the Lambda function handler, the part before the period is the file name, such as lambda_function.rb.
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The portion after the period, such as lambda_handler, indicates the method that gets invoked.
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The function receives two keyword arguments: 'event' and 'context'.
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The function returns a hash structure comprising a status code and body.
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You can also test your functions live through the console interface.
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Now, let's turn to creating an API Gateway in the AWS Console.
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Specify that you want to create a RESTful API and provide a name.
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Once created, you'll have access to the API routes and the corresponding HTTP verbs.
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For instance, you can create a GET request on the homepage and link it to a Lambda function.
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Next, you would see a visualization of the request flow from the API Gateway to the Lambda function and back.
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Now, let’s look at creating a scheduled event in CloudWatch.
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Navigate to the rules tab, select scheduled events, and specify your target Lambda function.
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You can specify details like frequency, such as executing every five minutes.
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This allows for various automated jobs running in the background.
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So, congratulations! We’ve had a crash course on serverless architecture.
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We discussed Lambda, API Gateway, and CloudWatch.
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In reality, most developers do not create all functions through the AWS Console.
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Instead, we use frameworks to code in serverless environments.
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What I developed, Jets, represents a system where you can easily manage your application infrastructure.
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Now, let's look at some Jet’s code.
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Here’s a simple function in Jets, which mirrors a typical Lambda function.
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Next, we have a Jets controller, which may look familiar.
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Here we have an application controller from which all controllers inherit.
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This controller contains public methods that translate into Lambda functions.
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Jets evaluates the code, translating these public methods into Lambda functions.
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Additionally, it provides helper methods to render JSON or XML.
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There’s also a 'params' helper which parses the event payload.
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Now let’s look at the routes file, which resembles typical route files you may know.
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This file forwards HTTP methods to the correct controller actions.
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These routes eventually provision API Gateway resources.
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You can also create scheduled jobs through jets that become CloudWatch rules.
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Jobs can run asynchronously without blocking web requests.
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The Jets framework creates all necessary resources efficiently, allowing developers to focus on the coding.
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So let's quickly revisit the components: methods in Ruby are converted into Lambda functions.
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Routes get translated to API Gateway resources, and jobs are scheduled through CloudWatch.
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The overall structure is quite traditional, following MVC design.
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There are controllers, helpers, models, and views where applicable.
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So you can see that Jets allows for a more productive and simplified experience.
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The Ruby language enhances this productivity, as it remains concise.
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With simplicity in the setup, you can create complex applications.
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So let's move on to the live demo portion. I’ll perform a live demonstration today.
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For the demo, I will go to the documentation and copy some commands.
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Let’s start by creating a new Jets project. I’ll run the command to initialize a new demo.
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This command generates a starter project with all the necessary files.
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Additionally, Jet performs a bundle install to set up dependencies.
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Once the installation is complete, I can show you the structure of the generated files.
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Inside the app folder, we have controllers and routes created.
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Next, I will generate scaffolding for a simple application using Jets.
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This command will create all necessary resources for a basic RESTful API.
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You can see a simple post controller has been generated.
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The controller exposes basic RESTful methods that map to Lambda functions.
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Once these resources are created, I can run a local server for testing purposes.
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I’ll bind this to a local environment for demonstration.
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As I run this server, I can navigate through the created scaffold and test its functionality.
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I’ll demonstrate some CRUD operations using this interface, editing and creating new posts.
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Now that the server is running, you can see the API responding.
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Once I introduce the URL endpoint to the API Gateway, I can hit the endpoints.
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I will show that all operations hookup correctly with the backend.
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It’s functioning well, allowing for basic CRUD operations on my newly scaffolded resource.
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This illustrates how simple it is to set up services using Jets.
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We can leverage the AWS infrastructure while focusing on Ruby.
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Let’s recap what we just accomplished.
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We created an API Gateway that routes requests to Lambda functions, along with database integration.
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This demonstrates how easy it is to combine these tools for a functional application.
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Next, Lambda can be envisioned as glue code.
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It serves as a connection point, coordinating various functions and resources.
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You can glue together different events using AWS services to trigger Lambda functions.
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Another use case is event-driven security and remediation.
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For instance, you might want to close port 22 if it gets opened to the world.
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You can create a CloudWatch rule that listens for changes and executes a Lambda function.
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This function can automatically remediate the network security incident.
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Next up, you can also integrate IoT devices with AWS Lambda.
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Smart devices can send data through Lambda functions to execute custom logic.
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For example, a smart kettle can send temperature readings and trigger actions.
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Lastly, let’s look at scheduled jobs via CloudWatch events.
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You can back up databases without needing dedicated servers for cron jobs.
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This can greatly simplify resource management and scalability.
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I will also mention the Jets resource model. The framework is built around easy resource creation.
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Utilizing the adaptability of Ruby, developers can extend Jets as they see fit.
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Realistically, programming with Ruby keeps the code concise and manageable.
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Moving forward, I believe the future relies on frameworks like Jets to harness cloud capabilities.
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Today, we touched on many concepts and tools available for serverless computing.
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Now, I’m happy to answer any questions about Jets or Ruby serverless architecture.
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If you have any queries about the framework or features, feel free to ask.
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I appreciate any feedback or thoughts regarding the functionalities.
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Thank you for attending; I hope you learned something valuable today.
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I’ll now be around for the next ten minutes to answer any further questions.
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Thank you again for your time.
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I’m looking forward to discussing more about Jets and serverless frameworks.
