Monorepo for Tangled
shuttle: wait for nix-daemon pids to be gone before waiting for the restarted one
Signed-off-by: dawn <dawn@tangled.org>
+60
-25
+60
-25
shuttle/src/nix_config.rs
+60
-25
shuttle/src/nix_config.rs
···
1
1
use crate::command::{self, Spec};
2
2
use crate::protocol::v1;
3
3
use anyhow::{Context, Result};
4
+
use nix::sys::signal::{self, Signal};
5
+
use nix::unistd::Pid;
4
6
use serde::{Deserialize, Serialize};
5
7
use std::collections::HashSet;
6
8
use std::fmt::Write as _;
···
160
162
const NIX_DAEMON_SOCKET: &str = "/nix/var/nix/daemon-socket/socket";
161
163
162
164
async fn restart_nix_daemon() {
163
-
let systemd = Path::new(SYSTEMCTL_EXECUTABLE).exists();
164
-
let spec = if systemd {
165
-
Spec::new(SYSTEMCTL_EXECUTABLE)
165
+
if Path::new(SYSTEMCTL_EXECUTABLE).exists() {
166
+
let spec = Spec::new(SYSTEMCTL_EXECUTABLE)
166
167
.args(["try-restart", "nix-daemon.service"])
167
-
.timeout(Duration::from_secs(5))
168
-
} else {
169
-
// on non-systemd we can just kill the daemon and it should restart
170
-
Spec::new("pkill")
171
-
.args(["-f", "nix-daemon"])
172
-
.timeout(Duration::from_secs(5))
168
+
.timeout(Duration::from_secs(5));
169
+
match command::run_capture(spec).await {
170
+
Ok(output) if output.success() => {}
171
+
Ok(output) => warn!(
172
+
exit_code = output.exit.exit_code,
173
+
error = ?output.exit.error,
174
+
output = %output.combined_lossy(),
175
+
"nix-daemon restart failed"
176
+
),
177
+
Err(error) => warn!(%error, "nix-daemon restart failed"),
178
+
}
179
+
return;
180
+
}
181
+
182
+
let old_pids = nix_daemon_pids();
183
+
if old_pids.is_empty() {
184
+
info!("no nix-daemon running, skipping restart");
185
+
return;
186
+
}
187
+
for pid in &old_pids {
188
+
if let Err(error) = signal::kill(*pid, Signal::SIGTERM) {
189
+
warn!(%error, pid = pid.as_raw(), "failed to signal nix-daemon");
190
+
}
191
+
}
192
+
193
+
// wait for nix daemon to be gone, kill is not sync
194
+
wait_pids_gone(&old_pids, Duration::from_secs(5)).await;
195
+
wait_for_nix_daemon_socket(Duration::from_secs(5)).await;
196
+
}
197
+
198
+
fn nix_daemon_pids() -> Vec<Pid> {
199
+
let self_pid = std::process::id();
200
+
let Ok(entries) = fs::read_dir("/proc") else {
201
+
return Vec::new();
173
202
};
203
+
entries
204
+
.flatten()
205
+
.filter_map(|entry| {
206
+
let pid = entry.file_name().to_str()?.parse::<i32>().ok()?;
207
+
if pid as u32 == self_pid {
208
+
return None;
209
+
}
210
+
let comm = fs::read_to_string(entry.path().join("comm")).ok()?;
211
+
(comm.trim() == "nix-daemon").then(|| Pid::from_raw(pid))
212
+
})
213
+
.collect()
214
+
}
174
215
175
-
match command::run_capture(spec).await {
176
-
Ok(output) if output.success() => {
177
-
if !systemd {
178
-
// init has to respawn the daemon before any step needs it
179
-
wait_for_nix_daemon_socket(Duration::from_secs(5)).await;
180
-
}
216
+
async fn wait_pids_gone(pids: &[Pid], timeout: Duration) {
217
+
let deadline = tokio::time::Instant::now() + timeout;
218
+
loop {
219
+
// signal 0 only checks for existence; Err (ESRCH) means it's gone
220
+
if !pids.iter().any(|pid| signal::kill(*pid, None).is_ok()) {
221
+
return;
181
222
}
182
-
// pkill exits 1 when nothing matched, ie. no daemon to restart
183
-
Ok(output) if !systemd && output.exit.exit_code == 1 => {
184
-
info!("no nix-daemon running, skipping restart")
223
+
if tokio::time::Instant::now() >= deadline {
224
+
warn!("old nix-daemon did not exit before restart timeout");
225
+
return;
185
226
}
186
-
Ok(output) => warn!(
187
-
exit_code = output.exit.exit_code,
188
-
error = ?output.exit.error,
189
-
output = %output.combined_lossy(),
190
-
"nix-daemon restart failed"
191
-
),
192
-
Err(error) => warn!(%error, "nix-daemon restart failed"),
227
+
tokio::time::sleep(Duration::from_millis(10)).await;
193
228
}
194
229
}
195
230