vcontainer-init: fix idle timeout detection to distinguish EOF from timeout

The read -t command returns different exit codes:
- 0: successful read
- 1: EOF (connection closed)
- >128: timeout (typically 142)

Previously, any empty result was treated as timeout, but when the host
closes the connection after PING/PONG, read returns EOF immediately.
This caused the daemon to shut down right after startup.

Now we capture the exit code and only trigger idle shutdown when
read actually times out (exit code > 128).

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/recipes-containers/vcontainer/files/vcontainer-init-common.sh b/recipes-containers/vcontainer/files/vcontainer-init-common.sh
index 5bfee9b7..21bbe9db 100755
--- a/recipes-containers/vcontainer/files/vcontainer-init-common.sh
+++ b/recipes-containers/vcontainer/files/vcontainer-init-common.sh
@@ -329,7 +329,10 @@ run_daemon_mode() {
     # Command loop with idle timeout
     while true; do
         CMD_B64=""
-        if read -t "$RUNTIME_IDLE_TIMEOUT" -r CMD_B64 <&3; then
+        read -t "$RUNTIME_IDLE_TIMEOUT" -r CMD_B64 <&3
+        READ_EXIT=$?
+
+        if [ $READ_EXIT -eq 0 ]; then
             log "Received: '$CMD_B64'"
             # Handle special commands
             case "$CMD_B64" in
@@ -419,14 +422,15 @@ run_daemon_mode() {
 
             log "Command completed (exit code: $EXEC_EXIT_CODE)"
         else
-            # Read returned non-zero: either timeout or error
-            if [ -z "$CMD_B64" ]; then
-                # Timeout expired with no data - shut down
+            # Read returned non-zero: either timeout or EOF
+            # Timeout returns >128 (typically 142), EOF returns 1
+            if [ $READ_EXIT -gt 128 ]; then
+                # Actual timeout - shut down
                 log "Idle timeout (${RUNTIME_IDLE_TIMEOUT}s), shutting down..."
                 echo "===IDLE_SHUTDOWN===" | cat >&3
                 break
             fi
-            # Empty line or other issue - just continue
+            # EOF or empty line - host closed connection, wait for reconnect
             sleep 0.1
         fi
     done