renefonseca/wasisdk repository overview

⁠WASI-SDK Tool Chain

This image provides the WASI-SDK tool chain ready for building WASI WebAssembly modules for running with wasmtime which is also included (see repo wasmtime). WASI (WebAssembly System Interface) provides an API layer (mostly POSIX compatible) to allow system integration.

You can learn more about wasmtime at https://wasmtime.dev/⁠. And WASI at https://wasi.dev/⁠.

If you like where WebAssembly is heading; you can consider following Bytecode Alliance (https://bytecodealliance.org/⁠).

The WebAssembly engine and WASI together provide a way to support many different platforms with a single shared executable without a major performance impact and at the same time provide a high level of security due to the separation of the runtime from the host system.

wasmtime and WASI are both very much in development so you can experience some issues.

The image is built using the scripts available at https://github.com/rene-fonseca/docker-webassembly⁠.

The image also includes the common tools git, make and cmake.

⁠Usage

First get the image:

docker pull renefonseca/wasisdk:latest

You can now enter the shell ready for building with WASI:

docker run -it renefonseca/wasisdk:latest bash

The WASI-SDK tool chain is available from the root.

If you use cmake you should build your project using commands like below:

mkdir build
cd build
cmake .. -DCMAKE_TOOLCHAIN_FILE=/wasi-sdk/share/cmake/wasi-sdk.cmake -DWASI_SDK_PREFIX=/wasi-sdk
cmake --build . --target install

You need to run the generated executables using wasmtime. However, some projects may not have been setup to handle this (e.g. for running ctest) in which case you can register WebAssembly binary format and that way run WebAssembly modules directly. The registration uses the binfmt subsystem. Note that registration requires privileged mode:

docker run --privileged renefonseca/wasisdk:latest register-webassembly.sh set

Once the WebAssembly format has been registered you can run WebAssembly modules directly. Make sure the file has chmod +x set.

docker run renefonseca/wasisdk:latest hello

You can remove the WebAssembly registration again using this command:

docker run --privileged renefonseca/wasisdk:latest register-webassembly.sh clear