config.assets.compile=true in Rails production, why not?

The Great Debate: config.assets.compile=true in Rails Production 🤔

So, you've stumbled upon the question of whether or not to set config.assets.compile to true in your Rails production environment. It's a bit of a tricky conundrum, and there are valid arguments on both sides. Let's dive in and explore the various aspects of this debate!

The Default Setting

By default, when you create a new Rails app using rails new, the config.assets.compile value is set to false in production. This means that Rails expects you to run rake assets:precompile before deploying your application. This command ensures that all your asset pipeline assets (CSS, JavaScript, images, etc.) are compiled and ready for production.

The Lazy Compilation Option

Now, setting config.assets.compile to true might sound appealing at first. It means that you no longer have to manually run the precompile command. Instead, when an asset is requested for the first time, it will be lazily compiled on the fly. This lazy compilation does come with a performance hit, particularly on the initial request, and you'll need a JavaScript runtime in your production environment to facilitate it.

But here's the interesting part: once the asset has been lazily compiled, subsequent accesses to the same asset should incur no additional performance hit. In theory, this means that your application's performance should be on par with precompiled assets, minus the need for running the precompile command. Seems like a win-win situation, right?

Potential Downsides

While the lazy compilation approach can offer convenience and potentially save you some time, there are a few considerations to keep in mind:

1. Increased First Request Time ⏳

As mentioned earlier, the initial request for a lazily compiled asset will experience a performance hit. This is because the asset needs to be compiled on the fly before it can be served. Depending on the complexity and size of your assets, this delay could be noticeable to users. If your application has heavy traffic or a demanding user base, this added delay may not be worth the convenience gained.

2. JavaScript Runtime Dependency 🏃‍♀️

Enabling lazy compilation requires a JavaScript runtime environment in your production setup. If you don't already have one configured, you'll need to set it up. While this may not be a showstopper, it does add some complexity to your deployment pipeline.

3. Development-Mode Behavior in Production 🔄

By setting config.assets.compile to true, you're essentially mimicking the behavior of Rails in development mode. While this may not immediately cause any issues, it can potentially introduce inconsistencies between your development and production environments. It's generally best to keep the behavior consistent across different environments to avoid unexpected surprises.

Conclusion: To Lazy Compile or Not to Lazy Compile?

In the end, whether or not to set config.assets.compile to true rests on your individual use case and priorities. If you have a small application with low traffic, and the convenience of not running the precompile command outweighs the potential delay on the first request, then lazy compilation might be an acceptable choice.

However, if your application has high traffic or relies heavily on speedy asset delivery, sticking to the standard precompiled assets approach is likely the safer bet. Additionally, keeping your production environment consistent with your development environment can help avoid confusion and potential bugs.

So, take a moment to evaluate your specific needs and make an informed decision. Remember, there's no one-size-fits-all solution, but understanding the trade-offs will help you choose the path that suits your project best!

Got any thoughts or experiences regarding this subject? Share them in the comments below and let's start a lively discussion! 😄🗣️