cargo-binstall/crates/detect-wasi/src/lib.rs
Félix Saparelli 4b00f5f143
Split crates and clean up structure of codebase (#294)
Co-authored-by: Jiahao XU <Jiahao_XU@outlook.com>
2022-08-20 11:24:12 +00:00

42 lines
1.3 KiB
Rust

use std::{
fs::File,
io::{Result, Write},
process::Command,
};
#[cfg(unix)]
use std::{fs::Permissions, os::unix::fs::PermissionsExt};
use tempfile::tempdir;
const WASI_PROGRAM: &[u8] = include_bytes!("miniwasi.wasm");
/// Detect the ability to run WASI
///
/// This attempts to run a small embedded WASI program, and returns true if no errors happened.
/// Errors returned by the `Result` are I/O errors from the establishment of the context, not
/// errors from the run attempt.
///
/// On Linux, you can configure your system to run WASI programs using a binfmt directive. Under
/// systemd, write the below to `/etc/binfmt.d/wasi.conf`, with `/usr/bin/wasmtime` optionally
/// replaced with the path to your WASI runtime of choice:
///
/// ```plain
/// :wasi:M::\x00asm::/usr/bin/wasmtime:
/// ```
pub fn detect_wasi_runability() -> Result<bool> {
let progdir = tempdir()?;
let prog = progdir.path().join("miniwasi.wasm");
{
let mut progfile = File::create(&prog)?;
progfile.write_all(WASI_PROGRAM)?;
#[cfg(unix)]
progfile.set_permissions(Permissions::from_mode(0o777))?;
}
match Command::new(prog).output() {
Ok(out) => Ok(out.status.success() && out.stdout.is_empty() && out.stderr.is_empty()),
Err(_) => Ok(false),
}
}