[1.3] tests: add RUNC_CMDLINE for tests incompatible with functions

Sometimes we need to run runc through some wrapper (like nohup), but
because "__runc" and "runc" are bash functions in our test suite this
doesn't work trivially -- and you cannot just pass "$RUNC" because you
you need to set --root for rootless tests.

So create a setup_runc_cmdline helper which sets $RUNC_CMDLINE to the
beginning cmdline used by __runc (and switch __runc to use that).

Signed-off-by: Aleksa Sarai <[email protected]>
(Cherry-pick of commit d1f6acf.)
Signed-off-by: Aleksa Sarai <[email protected]>

Author: cyphar

tests/integration/helpers.bash

@@ -57,10 +57,17 @@ function runc() {
 	CMDNAME="$(basename "$RUNC")" sane_run __runc "$@"
 }
 
+function setup_runc_cmdline() {
+	RUNC_CMDLINE=("$RUNC")
+	[[ -v RUNC_USE_SYSTEMD ]] && RUNC_CMDLINE+=("--systemd-cgroup")
+	[[ -n "${ROOT:-}" ]] && RUNC_CMDLINE+=("--root" "$ROOT/state")
+	export RUNC_CMDLINE
+}
+
 # Raw wrapper for runc.
 function __runc() {
-	"$RUNC" ${RUNC_USE_SYSTEMD+--systemd-cgroup} \
-		${ROOT:+--root "$ROOT/state"} "$@"
+	setup_runc_cmdline
+	"${RUNC_CMDLINE[@]}" "$@"
 }
 
 # Wrapper for runc spec.