Implement --daemonize for pueued

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "pueue"
 description = "A cli tool for managing long running shell commands."
-version = "0.1.0"
+version = "0.1.1"
 authors = ["Arne Beer <contact@arne.beer>"]
 homepage = "https://github.com/nukesor/pueue"
 repository = "https://github.com/nukesor/pueue"

README.md

@@ -163,17 +163,20 @@ This would help me a lot!
 
 ## Starting the Daemon
 
+### Local
+Just run `pueued` anywhere on your commandline. It'll exit if you close the terminal, though.
+
+### Background
+To fork `pueued` into the background, add the `-d` or `--daemonize` flag. E.g. `pueued -d`. \
+The daemon can be then shut down using the client: `pueue shutdown`
+
 ### Systemd
 If you use Systemd and don't install Pueue with a package manager, place `pueued.service` in `/etc/systemd/user/`.  
 Afterward, every user can start/enable their own session with:  
 
         systemctl --user start pueued.service
         systemctl --user enable pueued.service
 
-### Local
-Just run `pueued` anywhere on your commandline. It'll exit if you close the terminal, though.
-
-
 ## Utilities
 
 ### JSON Support

daemon/cli.rs

@@ -15,7 +15,7 @@ pub struct Opt {
     /// Closing the terminal won't kill the daemon any longer.
     /// This should be avoided and rather be properly done using a service manager.
     #[structopt(short, long)]
-    daemonize: bool,
+    pub daemonize: bool,
 
     //    /// The ip the daemon listens on. Overwrites the address in the config file
     //    #[structopt(short, long)]

daemon/main.rs

@@ -1,5 +1,6 @@
 use ::anyhow::{bail, Error, Result};
 use ::simplelog::{Config, LevelFilter, SimpleLogger};
+use ::std::process::Command;
 use ::std::fs::create_dir_all;
 use ::std::path::Path;
 use ::std::sync::mpsc::channel;
@@ -34,6 +35,10 @@ async fn main() -> Result<()> {
     // Parse commandline options
     let opt = Opt::from_args();
 
+    if opt.daemonize {
+        fork_daemon(&opt)?;
+    }
+
     // Set the verbosity level for the client app
     if opt.verbose >= 3 {
         SimpleLogger::init(LevelFilter::Debug, Config::default())?;
@@ -63,7 +68,7 @@ async fn main() -> Result<()> {
 }
 
 /// Initialize all directories needed for normal operation
-pub fn init_directories(path: &String) {
+fn init_directories(path: &String) {
     let pueue_dir = Path::new(path);
     if !pueue_dir.exists() {
         if let Err(error) = create_dir_all(&pueue_dir) {
@@ -93,3 +98,25 @@ pub fn init_directories(path: &String) {
         }
     }
 }
+
+/// This is a simple and cheap custom fork method
+/// Simply spawn a new child with identical arguments and exit right away
+fn fork_daemon(opt: &Opt) -> Result<()> {
+    let mut arguments = Vec::<String>::new();
+
+    if let Some(port) = &opt.port {
+        arguments.push("--port".to_string());
+        arguments.push(port.clone());
+    }
+
+    if opt.verbose > 0 {
+        arguments.push("-".to_string() + &" ".repeat(opt.verbose as usize));
+    }
+
+    Command::new("pueued")
+        .args(&arguments)
+        .spawn()?;
+
+    println!("Pueued is now running in the background");
+    std::process::exit(0);
+}

shared/protocol.rs

@@ -1,6 +1,7 @@
 use ::anyhow::Result;
 use ::async_std::net::TcpStream;
 use ::async_std::prelude::*;
+use ::log::debug;
 use ::byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
 use ::std::io::Cursor;
 
@@ -9,6 +10,7 @@ use crate::message::*;
 /// Convenience wrapper around send_bytes
 /// Deserialize a message and feed the bytes into send_bytes
 pub async fn send_message(message: &Message, socket: &mut TcpStream) -> Result<()> {
+    debug!("Sending message: {:?}", message);
     // Prepare command for transfer and determine message byte size
     let payload = serde_json::to_string(message)
         .expect("Failed to serialize message.")
@@ -70,6 +72,7 @@ pub async fn receive_message(socket: &mut TcpStream) -> Result<Message> {
 
     // Deserialize the message
     let message = String::from_utf8(payload_bytes)?;
+    debug!("Received message: {:?}", message);
     let message: Message = serde_json::from_str(&message)?;
 
     Ok(message)