kernel-node · rustaceanrob · Mar 11, 2026 · Mar 9, 2026 · Mar 9, 2026
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -22,6 +22,7 @@ capnp-rpc = "0.23"
 tokio = { version = "1", features = ["net", "rt"] }
 tokio-util = { version = "0.7", features = ["compat"] }
 futures = "0.3.0"
+libc = "0.2"
 
 [build-dependencies]
 capnpc = "0.23"

diff --git a/config_spec.toml b/config_spec.toml
@@ -15,3 +15,8 @@ name = "connect"
 type = "String"
 optional = true
 doc = "Connect only to this node (format: ip:port or hostname:port)"
+
+[[param]]
+name = "daemon"
+type = "bool"
+default = "false"
diff --git a/src/bin/cli.rs b/src/bin/cli.rs
@@ -79,6 +79,7 @@ fn main() {
             Commands::Stop => {
                 let shutdown_req = client.shutdown_request();
                 shutdown_req.send().promise.await.unwrap();
+                println!("Kernel node stopping...");
             }
         }
     }))

diff --git a/src/bin/node.rs b/src/bin/node.rs
@@ -15,7 +15,10 @@ use bitcoinkernel::{
     core::BlockHashExt, prelude::BlockValidationStateExt, ChainType, ChainstateManagerBuilder,
     Context, ContextBuilder, Log, Logger, SynchronizationState, ValidationMode,
 };
-use kernel_node::peer::{BitcoinPeer, NodeState, TipState};
+use kernel_node::{
+    daemonize::Daemonize,
+    peer::{BitcoinPeer, NodeState, TipState},
+};
 use kernel_node::{
     ipc::IpcInterface,
     kernel_util::{ChainExt, DirnameExt},
@@ -347,6 +350,12 @@ fn main() {
     START.call_once(|| {
         setup_logging();
     });
+    if config.daemon {
+        let daemonize = Daemonize::new(config.datadir.data_dir());
+        info!("Kernel node starting...");
+        daemonize.fork().unwrap();
+    }
+
     let (shutdown_tx, shutdown_rx) = mpsc::channel();
     let ipc_shutdown = shutdown_tx.clone();
 

diff --git a/src/daemonize.rs b/src/daemonize.rs
@@ -0,0 +1,40 @@
+use std::{
+    fs::{self, File},
+    os::fd::IntoRawFd,
+};
+
+const MASK_OCTAL: u32 = 0o027;
+const DEV_NULL: &str = "/dev/null";
+
+pub struct Daemonize {
+    working_directory: String,
+}
+
+impl Daemonize {
+    pub fn new(working_directory: String) -> Self {
+        Self { working_directory }
+    }
+
+    pub fn fork(self) -> std::io::Result<()> {
+        match unsafe { libc::fork() } {
+            -1 => return Err(std::io::Error::last_os_error()),
+            0 => (),
+            _pid => std::process::exit(0),
+        }
+        if unsafe { libc::setsid() } == -1 {
+            return Err(std::io::Error::last_os_error());
+        }
+        std::env::set_current_dir(&self.working_directory)?;
+        unsafe { libc::umask(MASK_OCTAL) };
+        let null_std_in = File::open(DEV_NULL)?;
+        unsafe { libc::dup2(null_std_in.into_raw_fd(), libc::STDIN_FILENO) };
+        let pid_file = format!("{}/node.pid", self.working_directory);
+        let process_id = std::process::id();
+        fs::write(pid_file, process_id.to_string())?;
+        let log_file = format!("{}/node.log", self.working_directory);
+        let log_file = File::create(log_file)?;
+        unsafe { libc::dup2(log_file.into_raw_fd(), libc::STDOUT_FILENO) };
+        unsafe { libc::dup2(libc::STDOUT_FILENO, libc::STDERR_FILENO) };
+        Ok(())
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
@@ -1,3 +1,4 @@
+pub mod daemonize;
 pub mod ipc;
 pub mod kernel_util;
 pub mod peer;