feat: daemon-owned session lifecycle (#44)

* feat: daemon-owned session lifecycle

* feat: expiry handling

Author: junhsss

src/browser/daemon/client.rs

@@ -14,11 +14,18 @@ pub struct DaemonClient {
 }
 
 impl DaemonClient {
-    pub async fn connect(session_id: &str) -> Result<Self> {
-        let sock = process::socket_path(session_id);
-        let stream = UnixStream::connect(&sock).await.map_err(|_| {
-            anyhow::anyhow!("Cannot connect to browser daemon. Is a session running?")
-        })?;
+    pub async fn connect(session_name: &str) -> Result<Self> {
+        let sock = process::socket_path(session_name);
+        let stream = match UnixStream::connect(&sock).await {
+            Ok(s) => s,
+            Err(_) => {
+                // Socket file may exist but the daemon process is dead — clean up
+                process::cleanup_if_dead(session_name);
+                return Err(anyhow::anyhow!(
+                    "Cannot connect to browser daemon. Is a session running?"
+                ));
+            }
+        };
         let (read_half, write_half) = tokio::io::split(stream);
         Ok(Self {
             reader: BufReader::new(read_half),

src/browser/daemon/process.rs

@@ -3,38 +3,93 @@ use std::time::Duration;
 
 use anyhow::{Result, bail};
 
-pub fn socket_path(session_id: &str) -> PathBuf {
-    crate::config::config_dir().join(format!("daemon-{session_id}.sock"))
+use super::protocol::DaemonCreateParams;
+
+/// Scan the config directory for `daemon-*.sock` files and return the session names.
+pub fn list_daemon_names() -> Vec<String> {
+    let dir = crate::config::config_dir();
+    let Ok(entries) = std::fs::read_dir(&dir) else {
+        return vec![];
+    };
+    let mut names = Vec::new();
+    for entry in entries.flatten() {
+        let name = entry.file_name();
+        let name = name.to_string_lossy();
+        if let Some(rest) = name.strip_prefix("daemon-") {
+            if let Some(session_name) = rest.strip_suffix(".sock") {
+                if !session_name.is_empty() {
+                    names.push(session_name.to_string());
+                }
+            }
+        }
+    }
+    names
+}
+
+pub fn socket_path(session_name: &str) -> PathBuf {
+    crate::config::config_dir().join(format!("daemon-{session_name}.sock"))
+}
+
+pub fn pid_path(session_name: &str) -> PathBuf {
+    crate::config::config_dir().join(format!("daemon-{session_name}.pid"))
 }
 
-pub fn pid_path(session_id: &str) -> PathBuf {
-    crate::config::config_dir().join(format!("daemon-{session_id}.pid"))
+fn log_path(session_name: &str) -> PathBuf {
+    crate::config::config_dir().join(format!("daemon-{session_name}.log"))
 }
 
-fn log_path(session_id: &str) -> PathBuf {
-    crate::config::config_dir().join(format!("daemon-{session_id}.log"))
+pub fn cleanup_stale(session_name: &str) {
+    let _ = std::fs::remove_file(socket_path(session_name));
+    let _ = std::fs::remove_file(pid_path(session_name));
 }
 
-pub fn cleanup_stale(session_id: &str) {
-    let _ = std::fs::remove_file(socket_path(session_id));
-    let _ = std::fs::remove_file(pid_path(session_id));
+/// Check if the daemon process for this session is still alive using its PID file.
+/// Returns `false` if the PID file is missing, unreadable, or the process is not running.
+pub fn is_daemon_alive(session_name: &str) -> bool {
+    let pid_file = pid_path(session_name);
+    let Ok(contents) = std::fs::read_to_string(&pid_file) else {
+        return false;
+    };
+    let Ok(pid) = contents.trim().parse::<i32>() else {
+        return false;
+    };
+    // kill -0 checks process existence without sending a signal
+    std::process::Command::new("kill")
+        .args(["-0", &pid.to_string()])
+        .stdout(std::process::Stdio::null())
+        .stderr(std::process::Stdio::null())
+        .status()
+        .map(|s| s.success())
+        .unwrap_or(false)
 }
 
-/// Spawn a daemon process for the given session. The CDP URL is passed via
+/// If a daemon's socket file exists but its process is dead, clean up stale files.
+/// Returns `true` if stale files were removed.
+pub fn cleanup_if_dead(session_name: &str) -> bool {
+    if socket_path(session_name).exists() && !is_daemon_alive(session_name) {
+        cleanup_stale(session_name);
+        return true;
+    }
+    false
+}
+
+/// Spawn a daemon process for the given session. The create params are passed via
 /// environment variable to avoid leaking API keys in the process list.
-pub fn spawn_daemon(session_id: &str, cdp_url: &str) -> Result<()> {
+pub fn spawn_daemon(session_name: &str, params: &DaemonCreateParams) -> Result<()> {
     let exe = std::env::current_exe()?;
 
-    cleanup_stale(session_id);
+    cleanup_stale(session_name);
 
     let config_dir = crate::config::config_dir();
     std::fs::create_dir_all(&config_dir)?;
 
-    let log = std::fs::File::create(log_path(session_id))?;
+    let log = std::fs::File::create(log_path(session_name))?;
+
+    let params_json = serde_json::to_string(params)?;
 
     std::process::Command::new(exe)
-        .args(["__daemon", "--session-id", session_id])
-        .env("STEEL_DAEMON_CDP_URL", cdp_url)
+        .args(["__daemon", "--session-name", session_name])
+        .env("STEEL_DAEMON_PARAMS", params_json)
         .stdin(std::process::Stdio::null())
         .stdout(log.try_clone()?)
         .stderr(log)
@@ -44,8 +99,8 @@ pub fn spawn_daemon(session_id: &str, cdp_url: &str) -> Result<()> {
 }
 
 /// Wait until the daemon socket is connectable.
-pub async fn wait_for_daemon(session_id: &str, timeout: Duration) -> Result<()> {
-    let sock = socket_path(session_id);
+pub async fn wait_for_daemon(session_name: &str, timeout: Duration) -> Result<()> {
+    let sock = socket_path(session_name);
     let start = std::time::Instant::now();
 
     while start.elapsed() < timeout {
@@ -62,23 +117,23 @@ pub async fn wait_for_daemon(session_id: &str, timeout: Duration) -> Result<()>
 }
 
 /// Send a shutdown command to a running daemon and clean up files.
-pub async fn stop_daemon(session_id: &str) -> Result<()> {
+pub async fn stop_daemon(session_name: &str) -> Result<()> {
     use super::client::DaemonClient;
     use super::protocol::DaemonCommand;
 
-    if let Ok(mut client) = DaemonClient::connect(session_id).await {
+    if let Ok(mut client) = DaemonClient::connect(session_name).await {
         let _ = client.send(DaemonCommand::Shutdown).await;
     }
 
     tokio::time::sleep(Duration::from_millis(200)).await;
-    cleanup_stale(session_id);
+    cleanup_stale(session_name);
 
     Ok(())
 }
 
 /// Kill a daemon process by reading its PID file, then clean up.
-pub fn kill_daemon(session_id: &str) -> Result<()> {
-    let pid_file = pid_path(session_id);
+pub fn kill_daemon(session_name: &str) -> Result<()> {
+    let pid_file = pid_path(session_name);
     if let Ok(contents) = std::fs::read_to_string(&pid_file)
         && let Ok(pid) = contents.trim().parse::<u32>()
     {
@@ -89,6 +144,6 @@ pub fn kill_daemon(session_id: &str) -> Result<()> {
             .stderr(std::process::Stdio::null())
             .status();
     }
-    cleanup_stale(session_id);
+    cleanup_stale(session_name);
     Ok(())
 }

src/browser/daemon/protocol.rs

@@ -2,6 +2,66 @@ use std::collections::HashMap;
 
 use serde::{Deserialize, Serialize};
 
+use crate::api::session::CreateSessionOptions;
+use crate::config::settings::ApiMode;
+
+/// Parameters passed to the daemon subprocess via env var so it can create
+/// the cloud session itself.  Serialized as JSON into `STEEL_DAEMON_PARAMS`.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DaemonCreateParams {
+    pub api_key: Option<String>,
+    pub base_url: String,
+    pub mode: ApiMode,
+    pub session_name: String,
+    // Flattened CreateSessionOptions fields:
+    pub stealth: bool,
+    pub proxy_url: Option<String>,
+    pub timeout_ms: Option<u64>,
+    pub headless: Option<bool>,
+    pub region: Option<String>,
+    pub solve_captcha: bool,
+    pub profile_id: Option<String>,
+    pub persist_profile: bool,
+    pub namespace: Option<String>,
+    pub credentials: bool,
+}
+
+impl DaemonCreateParams {
+    pub fn to_create_options(&self) -> CreateSessionOptions {
+        CreateSessionOptions {
+            stealth: self.stealth,
+            proxy_url: self.proxy_url.clone(),
+            timeout_ms: self.timeout_ms,
+            headless: self.headless,
+            region: self.region.clone(),
+            solve_captcha: self.solve_captcha,
+            profile_id: self.profile_id.clone(),
+            persist_profile: self.persist_profile,
+            namespace: self.namespace.clone(),
+            credentials: self.credentials,
+        }
+    }
+}
+
+/// Information about the daemon-managed session, returned by `GetSessionInfo`.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SessionInfo {
+    pub session_id: String,
+    pub session_name: String,
+    pub mode: ApiMode,
+    pub status: Option<String>,
+    pub connect_url: Option<String>,
+    pub viewer_url: Option<String>,
+    pub profile_id: Option<String>,
+    /// Session timeout in milliseconds (from create params). `None` = no timeout.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub timeout_ms: Option<u64>,
+    /// Epoch milliseconds when the session was created. Used with `timeout_ms`
+    /// to compute remaining time on the client side.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub created_at_ms: Option<u64>,
+}
+
 #[derive(Debug, PartialEq, Serialize, Deserialize)]
 pub struct DaemonRequest {
     pub id: u64,
@@ -158,6 +218,7 @@ pub enum DaemonCommand {
     Close,
     Ping,
     Shutdown,
+    GetSessionInfo,
 }
 
 #[derive(Debug, PartialEq, Serialize, Deserialize)]