Environment Variables Overview

[00:00:00]
>> Scott Moss: I'm gonna introduce you to one of my first opinions that I don't think a lot of people solve very well, but I do this with every single it's one of the first things I do with every single note every single Node JS project I make, whether it's an API or some script or some and these days it's mostly like an AI agent. Is standardizing and typing out. My in my environment variables so. What are environment variables Let's talk about that.

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What are environment variables Let's talk about that. Let me go back to the notes. And that's what you'll see like in these imports and stuff, but so environment variables, if you haven't taken the note course or you haven't done any system levering system level OS programming, you might be wondering what an environment variable is, even though you've probably done them in React. But the way that they're done on the front and is very much simulated.

[00:00:37]
But the way that they're done on the front and is very much simulated. They're not actually environment variables. I mean, they're injected through the environment, but they aren't read like environment variables when you use an environment variable on a build system like Vite or Webpack or something, what's actually happening is that so if you do like pro like in the case of NextJS if you do like process. Ev.

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Ev. And the next JS makes you do like next_ public the name of the environment variable what actually happens if you use that on the front end is that gets substituted out for the actual value of the environment variable. So if you were to go look at the output of that code. And you were to examine it, what you would see is the value of the environment variable, which could be dangerous because most of the time your environment variables are secrets that you don't want people to see, so congratulations you did prevent GitHub and people on GitHub from seeing it, but you didn't prevent anyone from looking at your source code from seeing it because that's not how environment variables work.

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And you were to examine it, what you would see is the value of the environment variable, which could be dangerous because most of the time your environment variables are secrets that you don't want people to see, so congratulations you did prevent GitHub and people on GitHub from seeing it, but you didn't prevent anyone from looking at your source code from seeing it because that's not how environment variables work. That's not the case of the server. There is no. You know, the code, your server code isn't gonna be inspected unless someone gets access to your server.

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You know, the code, your server code isn't gonna be inspected unless someone gets access to your server. So an environment variable is essentially a variable that gets injected into the environment and it's a and it's a great way to like change. Configuration and options within your server without having to change the code. Right, the equivalent of this on the front end would be like a feature flag.

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Right, the equivalent of this on the front end would be like a feature flag. If you've ever done feature flags on the front end where you can be like, oh, you know, I wanna or if you do AB testing or anything like that where it's like I can dynamically change something about this front end without having to do a commit on git on GitHub or git and push it somewhere or like a headless CMS where you can go publish a new blog post on a headless CMS hit publish and your website immediately gets that because it's just dynamically pulling it in. environment variables are like the genesis of all of that. It's how we inject.

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It's how we inject. Variables dynamically into our environment and this is useful because one things are secret that we don't want to expose in our code bases so we don't wanna write them and two we want to reuse the same code base but across many different environments, right? Like we wanna use this code base we're writing right now locally on our computers. And locally on like if we were all on the same team, working on the same app, we that's in the mountain of environments, so we want to be able to make sure we can have our own values for our own environments.

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And locally on like if we were all on the same team, working on the same app, we that's in the mountain of environments, so we want to be able to make sure we can have our own values for our own environments. We're gonna use something probably staging will have its own environment variables, its own database, it's own URL, and then production will have its own stuff too. So how do we like swap out all those variables if they were hard coded? If I went into the app right now, so the database URL is this, and I put that right in the TypeScript file, well what happens when it's on staging or what happens when it's on your computer then what you gonna write all those in the file like it's impossible.

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If I went into the app right now, so the database URL is this, and I put that right in the TypeScript file, well what happens when it's on staging or what happens when it's on your computer then what you gonna write all those in the file like it's impossible. What if they change? With some of these variables are on a rotation and aren't set, they're dynamic in which most hosting providers, a lot of those variables are dynamic and they never are set, especially if you have something like a low balancer or something. So an environment variable is a way for you to dynamically change some value or set of values in your server without any code changes whatsoever.

[00:03:02]
So an environment variable is a way for you to dynamically change some value or set of values in your server without any code changes whatsoever. You typically do need to do a server restart but you don't need to change any code.