From 883114e2a320b2afb7be960be3a1add430c14328 Mon Sep 17 00:00:00 2001
From: Valentin Haudiquet <valentin.haudiquet@canonical.com>
Date: Tue, 2 Jun 2026 11:05:38 +0200
Subject: [PATCH] feat: automatically detach from `p logs -f` on job end

---
 p/src/commands/logs.rs | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/p/src/commands/logs.rs b/p/src/commands/logs.rs
index d38c1c0..a56e886 100644
--- a/p/src/commands/logs.rs
+++ b/p/src/commands/logs.rs
@@ -20,8 +20,29 @@ pub fn execute(job_id: &str, follow: bool) -> Result<()> {
             );
             print_log(worker, &log)?;
         } else {
-            // Stream live output. Ctrl+C kills ssh; the job keeps running.
-            ssh::run_output(worker, &format!("tail -n +1 -f {}", log))?;
+            // Stream live output and exit automatically when the job finishes.
+            //
+            // The script backgrounds `tail -f` (so its stdout still flows to the
+            // client through the SSH pipe), then polls for the exitcode file that
+            // run.sh writes the moment the job exits.  A 1-second sleep after
+            // detecting the exitcode file gives tail time to drain any bytes that
+            // were written to the log just before exitcode appeared.  `kill` +
+            // `wait` let tail flush its buffer before the SSH connection closes.
+            //
+            // Ctrl+C still works: it kills ssh, which sends SIGHUP to the remote
+            // shell, terminating the whole script including the tail background job.
+            let exitcode_path = format!("~/.p/jobs/{}/exitcode", job.id);
+            let follow_cmd = format!(
+                "tail -n +1 -f {log} & \
+                 TAIL_PID=$!; \
+                 while ! [ -f {exitcode} ]; do sleep 1; done; \
+                 sleep 1; \
+                 kill \"$TAIL_PID\" 2>/dev/null; \
+                 wait \"$TAIL_PID\" 2>/dev/null",
+                log = log,
+                exitcode = exitcode_path,
+            );
+            ssh::run_output(worker, &follow_cmd)?;
         }
     } else {
         print_log(worker, &log)?;