Fix firewall backend installation

test/interactive-install-flow.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+# shellcheck disable=SC1091,SC2034
+# SC1091: The installer path is provided by the test environment.
+# SC2034: Configuration globals are consumed by sourced installer functions.
+set -euo pipefail
+
+INSTALLER=${1:-/opt/openvpn-install.sh}
+export FORCE_COLOR=0 LOG_FILE="" NON_INTERACTIVE_INSTALL=n OUTPUT_FORMAT=table
+# shellcheck source=../openvpn-install.sh
+source "$INSTALLER"
+
+questions_called=n
+validation_called=n
+install_called=n
+
+isOpenVPNInstalled() {
+	return 1
+}
+
+requireNoOpenVPN() {
+	return 0
+}
+
+installQuestions() {
+	questions_called=y
+	VPN_SUBNET_IPV4=10.23.0.0
+	VPN_SUBNET_IPV6=fd42:23::
+	CLIENT_IPV6=n
+	ROUTE_INTERNET=y
+}
+
+validate_configuration() {
+	validation_called=y
+}
+
+installOpenVPN() {
+	install_called=y
+	if [[ ${VPN_GATEWAY_IPV4:-} != "10.23.0.1" ]]; then
+		echo "FAIL: Interactive install did not prepare the IPv4 VPN gateway" >&2
+		exit 1
+	fi
+	if [[ ${IPV6_SUPPORT:-} != "n" ]]; then
+		echo "FAIL: Interactive install did not prepare legacy IPv6 state" >&2
+		exit 1
+	fi
+}
+
+cmd_interactive
+
+for state in \
+	"questions_called:$questions_called" \
+	"validation_called:$validation_called" \
+	"install_called:$install_called"; do
+	if [[ ${state#*:} != "y" ]]; then
+		echo "FAIL: Interactive install skipped ${state%%:*}" >&2
+		exit 1
+	fi
+done
+
+echo "PASS: Interactive install prepares derived network configuration"