ephemeral: Preserve stdin for an interactive console

Bash redirects stdin from a background job to /dev/null when job
control is off. Preserve Podman stdin through bwrap so QEMU can
receive console input with -it.

Assisted-by: AI
Signed-off-by: Alexander Larsson <alexl@redhat.com>

Author: alexlarsson

crates/kit/scripts/entrypoint.sh

@@ -67,7 +67,9 @@ trap 'kill -TERM $BWRAP_PID 2>/dev/null; exit 0' INT TERM
 # Run bwrap in background so we can handle signals; xref
 # https://github.com/containers/bubblewrap/pull/586
 # But probably really we should switch to systemd
-bwrap --as-pid-1 --unshare-pid "${BWRAP_ARGS[@]}" --bind /run /run -- ${SELFEXE} container-entrypoint "$@" &
+# Bash normally gives a background command /dev/null on stdin, so
+# keep stdin attached so QEMU can receive input.
+bwrap --as-pid-1 --unshare-pid "${BWRAP_ARGS[@]}" --bind /run /run -- ${SELFEXE} container-entrypoint "$@" <&0 &
 BWRAP_PID=$!
 
 # Wait for bwrap to complete

docs/src/man/bcvk-ephemeral-run.md

@@ -67,6 +67,7 @@ This design allows bcvk to provide VM-like isolation and boot behavior while lev
 **--console**
 
     Connect the QEMU console to the container's stdio (visible via podman logs/attach)
+    Add **-i -t** to send keyboard input to the guest console.
 
 **--debug**
 
@@ -216,7 +217,7 @@ run and SSH into one command with automatic cleanup.
 
 **Debugging boot issues**:
 
-    bcvk ephemeral run --console --name debugvm localhost/mybootc
+    bcvk ephemeral run --console -it --name debugvm localhost/mybootc
 
 ## Understanding the Flags