server: write main daemon PID to run directory

so that we can easily get the main PID of the last recently launched
daemon. Will be used to get the control socket of that one for access
lgo rotate in a future patch

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

etc/proxmox-backup-proxy.service.in

@@ -9,6 +9,7 @@ After=proxmox-backup.service
 Type=notify
 ExecStart=%LIBEXECDIR%/proxmox-backup/proxmox-backup-proxy
 ExecReload=/bin/kill -HUP $MAINPID
+PIDFile=/run/proxmox-backup/proxy.pid
 Restart=on-failure
 User=%PROXY_USER%
 Group=%PROXY_USER%

etc/proxmox-backup.service.in

@@ -7,6 +7,7 @@ After=network.target
 Type=notify
 ExecStart=%LIBEXECDIR%/proxmox-backup/proxmox-backup-api
 ExecReload=/bin/kill -HUP $MAINPID
+PIDFile=/run/proxmox-backup/api.pid
 Restart=on-failure
 
 [Install]

src/bin/proxmox-backup-api.rs

@@ -78,6 +78,7 @@ async fn run() -> Result<(), Error> {
         },
     );
 
+    server::write_pid(buildcfg::PROXMOX_BACKUP_API_PID_FN)?;
     daemon::systemd_notify(daemon::SystemdNotify::Ready)?;
 
     let init_result: Result<(), Error> = try_block!({

src/bin/proxmox-backup-proxy.rs

@@ -145,6 +145,7 @@ async fn run() -> Result<(), Error> {
         },
     );
 
+    server::write_pid(buildcfg::PROXMOX_BACKUP_PROXY_PID_FN)?;
     daemon::systemd_notify(daemon::SystemdNotify::Ready)?;
 
     let init_result: Result<(), Error> = try_block!({

src/buildcfg.rs

@@ -12,12 +12,19 @@ macro_rules! PROXMOX_BACKUP_LOG_DIR_M { () => ("/var/log/proxmox-backup") }
 
 /// namespaced directory for in-memory (tmpfs) run state
 pub const PROXMOX_BACKUP_RUN_DIR: &str = PROXMOX_BACKUP_RUN_DIR_M!();
+
 /// namespaced directory for persistent logging
 pub const PROXMOX_BACKUP_LOG_DIR: &str = PROXMOX_BACKUP_LOG_DIR_M!();
 
 /// logfile for all API reuests handled by the proxy and privileged API daemons
 pub const API_ACCESS_LOG_FN: &str = concat!(PROXMOX_BACKUP_LOG_DIR_M!(), "/api/access.log");
 
+/// the PID filename for the unprivileged proxy daemon
+pub const PROXMOX_BACKUP_PROXY_PID_FN: &str = concat!(PROXMOX_BACKUP_RUN_DIR_M!(), "/proxy.pid");
+
+/// the PID filename for the privileged api daemon
+pub const PROXMOX_BACKUP_API_PID_FN: &str = concat!(PROXMOX_BACKUP_RUN_DIR_M!(), "/api.pid");
+
 /// Prepend configuration directory to a file name
 ///
 /// This is a simply way to get the full path for configuration files.

src/server.rs

@@ -4,6 +4,7 @@
 //! services. We want async IO, so this is built on top of
 //! tokio/hyper.
 
+use anyhow::{format_err, Error};
 use lazy_static::lazy_static;
 use nix::unistd::Pid;
 
@@ -24,6 +25,18 @@ pub fn pstart() -> u64 {
     *PSTART
 }
 
+pub fn write_pid(pid_fn: &str) -> Result<(), Error> {
+    let pid_str = format!("{}\n", *PID);
+    let opts = proxmox::tools::fs::CreateOptions::new();
+    proxmox::tools::fs::replace_file(pid_fn, pid_str.as_bytes(), opts)
+}
+
+pub fn read_pid(pid_fn: &str) -> Result<i32, Error> {
+    let pid = proxmox::tools::fs::file_get_contents(pid_fn)?;
+    let pid = std::str::from_utf8(&pid)?.trim();
+    pid.parse().map_err(|err| format_err!("could not parse pid - {}", err))
+}
+
 pub fn ctrl_sock_from_pid(pid: i32) -> String {
     format!("\0{}/control-{}.sock", buildcfg::PROXMOX_BACKUP_RUN_DIR, pid)
 }