Feature: daemonize (#225)

* feat: daemonize florestad

This commit introduces a `-daemon` cli option that starts florestad as a
background process, and optionally writes the PID to a specified file

README.md

@@ -111,6 +111,12 @@ After building, florestad and floresta-cli will be available in the target direc
 florestad
 ```
 
+You may run it as a background process with the `--daemon` flag.
+
+```bash
+florestad --daemon
+```
+
 This will start the full node, and you can connect to it with an Electrum wallet or with the `floresta-cli` tool.
 
 ```bash

florestad/Cargo.toml

@@ -38,6 +38,9 @@ jsonrpc-core-client = { version = "18.0.0", features = [
 zmq = { version = "0.10.0", optional = true }
 latest = "0.1.1"
 
+[target.'cfg(unix)'.dependencies]
+daemonize = { version = "0.5.0" }
+
 [lib]
 name = "florestad"
 path = "src/lib.rs"

florestad/src/cli.rs

@@ -70,7 +70,7 @@ pub struct Cli {
     /// Option for saving log into data_Dir
     ///
     /// if set, log will be saved into $DATA_DIR/output.log.
-    pub log_file: bool,
+    pub log_to_file: bool,
 
     #[arg(long, value_name = "PATH")]
     /// Where should we store data. This is the directory where we'll store the chainstate,
@@ -161,4 +161,18 @@ pub struct Cli {
     /// trust in the developer that the utreexo state is correct. Everything after the assumed
     /// height will be fully validated.
     pub assume_utreexo: bool,
+
+    #[cfg(unix)]
+    #[arg(long, default_value = "false")]
+    /// Whether we should run as a daemon
+    pub daemon: bool,
+
+    #[cfg(unix)]
+    #[arg(long, value_name = "FILE", requires = "daemon")]
+    /// A file to write the process id to
+    ///
+    /// In case you're using the daemon option, and you want to know the process id, you can
+    /// write it to a file. This option should be an absolute path to a file. Usually, you'd
+    /// write it to $DATA_DIR/florestad.pid
+    pub pid_file: Option<String>,
 }

florestad/src/florestad.rs

@@ -210,7 +210,6 @@ impl Florestad {
                 })
             })
             .unwrap_or("floresta".into());
-
         let data_dir = match self.config.network {
             crate::Network::Bitcoin => data_dir,
             crate::Network::Signet => data_dir + "/signet/",

florestad/src/main.rs

@@ -23,6 +23,8 @@ use std::time::Duration;
 
 use clap::Parser;
 use cli::Cli;
+#[cfg(unix)]
+use daemonize::Daemonize;
 use florestad::Config;
 use florestad::Florestad;
 use futures::executor::block_on;
@@ -35,15 +37,18 @@ fn main() {
     let config = Config {
         network: params.network.into(),
         debug: params.debug,
-        data_dir: params.data_dir,
+        data_dir: params.data_dir.clone(),
         cfilters: params.cfilters,
         proxy: params.proxy,
         rescan: params.rescan,
         assume_utreexo: params.assume_utreexo,
         connect: params.connect,
         wallet_xpub: params.wallet_xpub,
         config_file: params.config_file,
-        log_to_file: params.log_file,
+        #[cfg(unix)]
+        log_to_file: params.log_to_file || params.daemon,
+        #[cfg(not(unix))]
+        log_to_file: params.log_to_file,
         assume_valid: params.assume_valid,
         log_to_stdout: true,
         json_rpc_address: params.rpc_address,
@@ -53,6 +58,16 @@ fn main() {
         user_agent: format!("/Floresta:{}/", env!("GIT_DESCRIBE")),
         assumeutreexo_value: None,
     };
+
+    #[cfg(unix)]
+    if params.daemon {
+        let mut daemon = Daemonize::new();
+        if let Some(pid_file) = params.pid_file {
+            daemon = daemon.pid_file(pid_file);
+        }
+        daemon.start().expect("Failed to daemonize");
+    }
+
     let _rt = tokio::runtime::Builder::new_multi_thread()
         .enable_all()
         .worker_threads(4)