0.2.0

The WebAssembly engine has been upgraded to wasmtime 10. Bulwark switched to using the WASI component model in the process. This resulted in some changes to how plugins declare their handlers. The SDK now includes a bulwark_plugin procedural macro which is invoked like this:

use bulwark_wasm_sdk::*;

pub struct ExamplePlugin;

#[bulwark_plugin]
impl Handlers for ExamplePlugin {
    fn on_request_decision() -> Result {
        let _request = get_request();
        set_decision(Decision {
            accept: 0.0,
            restrict: 0.0,
            unknown: 1.0,
        })?;
        set_tags(["example-plugin"]);
        Ok(())
    }
}

After a plugin is compiled, it will need to be transformed into a component. This is inconvenient and a future release will likely not require this step, but for the time being it's required in the interests of expediency. The reactor shim needed can be downloaded from the wasmtime dev tag. The wasm-tools binary can be installed with cargo install wasm-tools.

wasm-tools component new target/wasm32-wasi/release/example_plugin.wasm --adapt wasi_snapshot_preview1=wasi_snapshot_preview1.reactor.wasm --output dist/example_plugin.wasm

The resulting .wasm file may then be run by Bulwark as a plugin.

Additionally, there have been some API changes to error handling. Plugins may now recover from errors that previously would have been a panic in 0.1.0. A new API call, append_tags was also added to allow plugin code to add tags bit-by-bit instead of all-at-once.