System Initiative

use std::{ io, num::TryFromIntError, process::ExitStatus, time::Duration, }; pub use nix::sys::signal::Signal; use nix::{ sys::signal, unistd::Pid, }; use telemetry::prelude::*; use thiserror::Error; use tokio::{ process::Child, time, }; const CHILD_WAIT_TIMEOUT_SECS: Duration = Duration::from_secs(10); #[remain::sorted] #[derive(Debug, Error)] pub enum ShutdownError { #[error("failed to wait on child process")] ChildWait(#[source] io::Error), #[error("failed to convert pid from u32 to i32--overflow")] PidOverflow(#[from] TryFromIntError), #[error("failed to signal child")] Signal(#[from] nix::errno::Errno), #[error("sending SIGKILL failed")] StartKill(#[source] io::Error), } pub async fn child_shutdown( child: &mut Child, signal: Option<Signal>, wait_timeout: Option<Duration>, ) -> Result<ExitStatus, ShutdownError> { if let (Some(signal), Some(pid)) = (signal, child.id()) { trace!("sending {} to child process {}", signal, pid); // Thanks, Clippy! // See: https://rust-lang.github.io/rust-clippy/master/index.html#cast_possible_wrap let pid = i32::try_from(pid)?; signal::kill(Pid::from_raw(pid), signal)?; } match time::timeout( wait_timeout.unwrap_or(CHILD_WAIT_TIMEOUT_SECS), child.wait(), ) .await { Ok(wait_result) => { let exit_status = wait_result.map_err(ShutdownError::ChildWait)?; if !exit_status.success() { debug!("child process had a nonzero exit; code={}", exit_status); } Ok(exit_status) } Err(_elapsed) => { child.start_kill().map_err(ShutdownError::StartKill)?; let exit_status = child.wait().await.map_err(ShutdownError::ChildWait)?; if !exit_status.success() { debug!("child process had a nonzero exit; code={}", exit_status); } Ok(exit_status) } } }