Python Web Apps that Fly with CDNs Transcripts
Chapter: Integrating Static Content
Lecture: CDNs and pull zones
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Before we open up the admin section over on bunny.net CDN page, let's talk real quickly about the different kinds of options
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and how the CDN might interact with our data so you know which one to pick. We're going to talk about something called a pull zone.
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And those are basically the origins that feed data into the large CDN network that is then shared with the rest of your users throughout the world.
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And we'll see how those click together. So let's imagine we have this web user, they're over there on their browser,
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could be a phone, it could even be a mobile app accessing the data over an API, doesn't matter. They just wanna make HTTP requests to your content.
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And so in the HTML, we're gonna put a link that says instead of forward slash static/image, it's gonna say CDN domain/static/image.
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As far as they're concerned, they're never getting data from your website. They're getting it from the CDN. So once they've gotten the HTML,
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their browser says, well, let's go look for these static files. And it asks the CDN, hey CDN, I'm looking for cat.jpg. CDN says, nope, no cat.jpg here,
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but that comes from a pull zone. And the pull zone is associated with this web app. and let me spring into action to first populate the network
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if I can find that file. There's two ways in which this might be done. It might be done through having something like S3 or some kind of cloud storage.
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So it could be a cloud drive over here and especially the CDN itself has a way to sort of connect its own cloud drive
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that it will look at, which is a really great option because it's local and super fast and even replicated for the CDN itself.
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So it might say, is that over here? But that's not the kind we're talking about. This is like large content, we're gonna come back to this later.
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So no, not this. This is one option, it's called a storage pull zone. It's not what we're doing now for our static content.
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What we're gonna do is we're gonna say CDN, you give them this public URL, kind of like ngrok actually, and you say, but come look on our website
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for the matching content. So they, the website, the web browser has said, I want cat.jpg. And it tried to get it from the CDN,
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the CDN knows about our location on the internet. So it comes back and says, I want /static/cat, cat.jpg. And our website says, great, I have that.
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So let me go pull this out of my static files here and I'll give it back to you. When it does, the CDN starts to replicate this to different locations.
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Probably not automatically, but as users ask for it from different regions, it'll replicate. We turn on what's called origin shield,
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transfers will start happening within the nodes of the CDN and not ever make its way back to our web app potentially.
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So it really takes the load off of distributing it. So this is called a URL or origin pull zone. Right, so we have these two kinds,
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store zones or origin or URL zones. For the static content section, what we're talking about is this web server style, this URL zone.
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We're gonna do that pretty much 100%. When we get to the large content section, we'll go over to the storage zone.
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This might be MP3 files, this might be video, this could be user generated content like, here's a ginormous PDF I uploaded to the website
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and I somehow need to share that back. Right, you wouldn't check those things into source control and then associate them with your web application.
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At least my rule of thumb is the stuff that's checked in the source control and the web app itself serves, that comes out of this origin zone.
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For the most part, loose files that are kept alongside your web app separately in things like S3 and other cloud storage,
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that probably belongs in a storage zone or pulled directly from places like S3.