From cf73a4d6b418ee27429f606a6e3b07306d681d5a Mon Sep 17 00:00:00 2001
From: Sayan- <1415138+Sayan-@users.noreply.github.com>
Date: Mon, 24 Aug 2026 20:44:59 +0000
Subject: [PATCH] Reap the log aggregator's tail processes

tailFile started tail -F and never waited on it. The wrapper runs as pid 1
in both the container and the unikernel, so every exited tail stayed a
zombie for the life of the instance.

A scan that ends on a read error rather than EOF leaves tail alive, so kill
it before waiting instead of parking the goroutine forever.
---
 server/cmd/wrapper/supervisord.go | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/server/cmd/wrapper/supervisord.go b/server/cmd/wrapper/supervisord.go
index 4672db47..1d2ad256 100644
--- a/server/cmd/wrapper/supervisord.go
+++ b/server/cmd/wrapper/supervisord.go
@@ -97,6 +97,17 @@ func tailFile(path string) {
 	for scanner.Scan() {
 		fmt.Printf("[%s] %s\n", label, scanner.Text())
 	}
+	// A clean scan ends when tail closes its stdout, i.e. when it has exited.
+	// A scan that ends on an error (a log line past the 1MB cap, say) leaves
+	// tail running, so kill it rather than block here forever.
+	//
+	// Either way we have to collect it: the wrapper is pid 1 in both the
+	// container and the unikernel, so a tail nobody waits on stays a zombie
+	// for the life of the instance.
+	if scanner.Err() != nil {
+		_ = cmd.Process.Kill()
+	}
+	_ = cmd.Wait()
 }
 
 func runStream(label, name string, args ...string) error {