Add http & https asset sources

[mrchantey]

Objective

• Fixes Feature: Upstream bevy_web_asset, allowing assets loaded via http #16307

Solution

• Add http & https asset sources

Testing

• Verify visually by running cargo run --example http_source

---

Showcase

Bevy now supports assets loaded via url!

Add the http_source feature to load assets served over the web, with support for both native and wasm targets. On native targets the http_source_cache feature will use a basic caching mechanism to avoid repeated network requests.

  // Simply use a url where you would normally use an `assets` path
  let handle = asset_server.load("https://raw.githubusercontent.com/bevyengine/bevy/refs/heads/main/assets/branding/bevy_bird_dark.png");
  commands.spawn(Sprite::from_image(handle));

[mrchantey]

It looks like surf and http-cache-surf have failed licence, vunerability & unmaintaned checks. Does that mean they're not allowed as first party dependencies?

[BenjaminBrienen]

It's possible to add an exception for the licenses, but unmaintained and vulnerable is pretty bad.

[mnmaita]

This could be done with something like reqwest maybe to avoid using the unmaintained crates. I successfully ran the example with it but my code is probably bad 😅. I can still push a PR as a showcase in case it serves as inspiration.

[MalekiRe]

Yep this looks awesome to me! Also I wasn't aware of the surf crate; I'll have to keep it in mind for any bevy dashboards I make in the future

[mrchantey]

I can still push a PR as a showcase in case it serves as inspiration.

@mnmaita actually that would be great, I've replaced surf and http-cache-surf with reqwest line for line but am a bit stuck at the moment with reqwest demanding to be run inside a tokio runtime.

// crates/bevy_asset/src/http_source.rs#134

    let client = reqwest_middleware::ClientBuilder::new(Client::new())
        .with(Cache(HttpCache {
            mode: CacheMode::Default,
            manager: CACacheManager::default(),
            options: HttpCacheOptions::default(),
        }))
        .build();

    let response = ContinuousPoll(client.get(str_path).send())
        .await

[jf908]

FWIW surf has a bug where any erroring http response >8kb stops every subsequent request from succeeding and is unlikely to ever be fixed which made me unable to use bevy_web_asset so I would personally appreciate a switch 😄.

If you can't get reqwest to work perhaps hyper would suffice since it's already in the dep tree for BRP? Perhaps too low level for this.

[mrchantey]

The council of bevy async wizards has spoken and we're going with ureq. It doesn't currently have a http-cache wrapper but I've opened an issue and the author might look into creating one when they have time. I guess its worth waiting a bit to see if ureq will get first party support before rolling our own http-cache wrapper, in which case this pr is ready for review :)

A few notes:

• We're still failing check-advisories & check-licences
• I used gh codespaces so wasnt able to cargo run --example http_source, can somebody please try running that?

[github-actions]

You added a new example but didn't add metadata for it. Please update the root Cargo.toml file.

[jf908]

• I used gh codespaces so wasnt able to cargo run --example http_source, can somebody please try running that?

Tested on Windows 11. The example prints a 404 error when the .meta file fails to load and doesn't show the sprite.

If I configure AssetPlugin to AssetMetaCheck::Never, it runs correctly.

I believe the asset is still supposed to load successfully even if the .meta file 404s so I think this is a bug?

[BenjaminBrienen]

We're still failing check-advisories & check-licences
I used gh codespaces

You can ignore that. It isn't a required check. Once those 2 small issues above are fixed, this should be in a pretty good state, I think.

[github-actions]

The generated examples/README.md is out of sync with the example metadata in Cargo.toml or the example readme template. Please run cargo run -p build-templated-pages -- update examples to update it, and commit the file change.

[mrchantey]

Ok I can confirm the example is working in wasm and native builds.

I'm a bit uneasy merging without native http caching. One of the primary use-cases for the feature is large assets and the current implementation wil re-download them every time the app is run. Maybe a stupidly naive cache, ie one that never automatically invalidates, is better than nothing?

In the long run it looks like a http-cache-ureq implementation would be ideal.

[mrchantey]

A simple native cache has been added and is ready for review

[jf908]

I have a couple of concerns but overall looks good. I really want this so I appreciate you spearheading it!

[github-actions]

You added a new feature but didn't update the readme. Please run cargo run -p build-templated-pages -- update features to update it, and commit the file change.

[jf908]

http_source should be added a required feature for the example but otherwise looks good to me

[mrchantey]

Awesome everything working as expected on ubuntu and wasm, and OnceCell has been replaced with LazyLock. The two extra bits of work mentioned in this pr are better AssetReadErrors and user-defined crypto providers, perhaps we can create seperate issue for each of those.

[alice-i-cecile]

Can I have a summary of the licensing situation as it currently stands? I want to make sure I have all the details straight :)

[mrchantey]

@alice-i-cecile this pr adds two licences:

• ureq > webpki-roots: MPL-2.0
• aws-lc-rs > aws-lc-sys: OpenSSL

ci still picks up ring because bevy_remote/client is still using default-features. Perhaps in another pr we can expose a general fetch function with the aws-lc-rs machinery used in this pr.

On another note this pr commit history has gotten super messy, it has a tonne of commits from when i was working out how to do ci checks locally and i think i did a bad merge, maybe I could open up a fresh one and link to it?