7 releases

Uses old Rust 2015

0.5.1 Apr 15, 2018
0.5.0 Apr 15, 2018
0.4.0-alpha.4 Sep 24, 2017
0.3.10 Aug 27, 2017

#19 in #ice


1.5K SLoC

Ice Core

Crates.io Build Status

Build efficient and reliable backend applications in WebAssembly.

What is it?

Ice is a container for backend applications in WebAssembly.

WebAssembly, which is mainly used to build client-side Web applications, can also be used to build server-side applications. With a managed execution environment and the underlying JIT (wasm-core) based on LLVM, Ice is able to achieve a higher level of security (and additional safety for C/C++ applications), provide platform-independent high-level abstractions, and bring a few special features like dynamic inter-machine application migration and more accurate service monitoring.


Latest nightly Rust and LLVM 6 are required.

cargo build --release

Get started

First, create a root directory to place configurations & applications:

mkdir my_ice_root
cd my_ice_root

Then, create a config file config.yaml in the root directory, whose format is defined in config.rs/Config:

  - name: hello_world
    path: ./apps/hello_world

Here we've specified an application named hello_world located at ./apps/hello_world, and the application will be automatically initialized when ice_core is launched.

Now let's initialize the hello_world application:

mkdir apps
cd apps
cargo new hello_world
cd hello_world

Add a [lib] section and the runtime library ia to the newly-created Cargo.toml:

name = "hello_world"
crate-type = ["cdylib"]

ia = "0.1"

And create another config.yaml in the hello_world directory, which is the application-level metadata definition (defined in config.rs/AppMetadata:

package_name: com.example.hello_world
bin: target/wasm32-unknown-unknown/release/hello_world.wasm

Write some code to print "Hello, world!" in src/lib.rs:

extern crate ia;

    println!("Hello, world!");

Build it:

cargo build --release --target wasm32-unknown-unknown

cd back to my_ice_root and launch ice_core:

ice_core config.yaml

and you should see your first hello_world application running!

Comparison with native binaries

The WebAssembly VM has to do some necessary checks and translations to ensure things work correctly. Therefore, it is always a little slower than precompiled native binaries. However, the difference is quite small and normally doesn't become the performance bottleneck for real-world applications.

In addition, Ice Core is able to provide a few features that a native environment doesn't provide:

  • Accurate permission control
  • Run-time inter-machine application migration (in progress)
  • Service monitoring and management (in progress)


~166K SLoC