initial

lib/checks.sh

@@ -0,0 +1,45 @@
+# Preflight checks. Fail loud and early with actionable messages.
+
+check_bash() {
+    if ((BASH_VERSINFO[0] < 4)); then
+        ui_err "$(t err_bash_version "$BASH_VERSION")"
+        exit 1
+    fi
+}
+
+check_docker() {
+    if ! command -v docker >/dev/null 2>&1; then
+        ui_err "$(t err_need_docker)"; exit 1
+    fi
+    if ! docker info >/dev/null 2>&1; then
+        ui_err "$(t err_docker_daemon)"; exit 1
+    fi
+    if ! docker compose version >/dev/null 2>&1; then
+        ui_err "$(t err_need_compose)"; exit 1
+    fi
+}
+
+check_openssl() {
+    if ! command -v openssl >/dev/null 2>&1; then
+        ui_err "$(t err_need_openssl)"; exit 1
+    fi
+}
+
+# is_port_free PORT — best effort; returns 0 if nothing seems to listen on it.
+is_port_free() {
+    local port="$1"
+    if command -v lsof >/dev/null 2>&1; then
+        ! lsof -nP -iTCP:"$port" -sTCP:LISTEN >/dev/null 2>&1
+    elif command -v nc >/dev/null 2>&1; then
+        ! nc -z localhost "$port" >/dev/null 2>&1
+    else
+        return 0  # can't check — assume free
+    fi
+}
+
+preflight() {
+    check_bash
+    check_docker
+    check_openssl
+    ui_ok "$(t preflight_ok)"
+}