Please install the prerequisites first!
The src/main.rs source code shows how to access OS services through standard libraries.
- Access the random number generator in the OS
- Access the local file system
- Access env vars in the OS
- Access command line args when starting this app
Compile the Rust source code project to a Wasm bytecode file.
$ cargo build --target wasm32-wasi --release
Run the Wasm bytecode file in WasmEdge CLI.
$ wasmedge --dir .:. target/wasm32-wasi/release/wasi.wasm
Random number: -1157533356
Random bytes: [159, 159, 9, 119, 106, 172, 207, 82, 173, 145, 233, 214, 104, 35, 23, 53, 155, 12, 102, 231, 117, 67, 192, 215, 207, 202, 128, 198, 213, 41, 235, 57, 89, 223, 138, 70, 185, 137, 74, 162, 42, 20, 226, 177, 114, 170, 172, 39, 149, 99, 122, 68, 115, 205, 155, 202, 4, 48, 178, 224, 124, 42, 24, 56, 215, 90, 203, 150, 106, 128, 127, 201, 177, 187, 20, 195, 172, 56, 72, 28, 53, 163, 59, 36, 129, 160, 69, 203, 196, 72, 113, 61, 46, 249, 81, 134, 94, 134, 159, 51, 233, 247, 253, 116, 202, 210, 100, 75, 74, 95, 197, 44, 81, 87, 89, 115, 20, 226, 143, 139, 50, 60, 196, 59, 206, 105, 161, 226]
Printed from wasi: This is from a main function
This is from a main function
The env vars are as follows.
The args are as follows.
wasi.wasm
File content is This is in a file
The Dockerfile follows the above steps to build and package a lightweight OCI-compliant container image for the Wasm app.
Now, we need to publish the container image to Docker Hub.
You just need to specify that the WasmEdge application image is for the wasi/wasm platform.
$ docker buildx build --provenance=false --platform wasi/wasm -t secondstate/rust-example-wasi .
... ...
$ docker push secondstate/rust-example-wasi
Then, with Docker Desktop and Wasm support enabled, you can run it.
$ docker run --rm --runtime=io.containerd.wasmedge.v1 --platform=wasi/wasm secondstate/rust-example-wasi:latest