Expand description
Small crate which helps with writing daemon applications in Rust.
I am aware about daemonize and daemonize-me crates, but needed some extended functionality like locking PID file and searching for running daemon.
Complete example:
use daemonizr::{Daemonizr, DaemonizrError, Group, Stderr, Stdout, User};
use std::{path::PathBuf, process::exit, thread::sleep, time::Duration};
fn main() {
match Daemonizr::new()
.work_dir(PathBuf::from("/Users/alex/git/private/daemonizr"))
.expect("invalid path")
.as_user(User::by_name("alex").expect("invalid user"))
.as_group(Group::by_name("staff").expect("invalid group"))
.pidfile(PathBuf::from("dmnzr.pid"))
.stdout(Stdout::Redirect(PathBuf::from("dmnzr.out")))
.stderr(Stderr::Redirect(PathBuf::from("dmnzr.err")))
.umask(0o027)
.expect("invalid umask")
.spawn()
{
Err(DaemonizrError::AlreadyRunning) => {
/* search for the daemon's PID */
match Daemonizr::new()
.work_dir(PathBuf::from("/Users/alex/git/private/daemonizr"))
.unwrap()
.pidfile(PathBuf::from("dmnzr.pid"))
.search()
{
Err(x) => eprintln!("error: {}", x),
Ok(pid) => {
eprintln!("another daemon with pid {} is already running", pid);
exit(1);
}
};
}
Err(e) => eprintln!("DaemonizrError: {}", e),
Ok(()) => { /* We are in daemon process now */ }
};
/* actual daemon work goes here */
println!("write something to stdout");
eprintln!("write something to stderr");
sleep(Duration::from_secs(60));
println!("Daemon exits.")
}
Hint:
⚠️ This crate will only work on POSIX compatible systems, where the “nix” and “libc” crates are available.
Structs
- Daemonizr holds context needed for spawning the daemon process.
Enums
- Error type reported by daemonizr.
- Group object holds a valid group id (GID) to change to after child process has been daemonized.
- Determines behaviour for “stderr” file descriptor
- Determines behaviour for “stdout” file descriptor
- User object holds a valid user id (UID) to change to after child process has been daemonized.