added ufw enable

src/methods/enable.js

@@ -0,0 +1,23 @@
+const {exec} = require("child_process");
+const {promisify} = require("util");
+const promisifiedExec = promisify(exec);
+
+module.exports.enable = async function() {
+  try {
+    // https://serverfault.com/a/790150
+    let res = await promisifiedExec(`echo "y" | sudo ufw enable`);
+
+    if (res.stderr) throw new Error(res.stderr);
+
+    if (res.stdout) {
+      if (res.stdout == "Firewall is active and enabled on system startup") {
+        return true;
+      } else {
+        console.log(res.stdout);
+        return false;
+      };
+    };
+  } catch (err) {
+    throw new Error(err);
+  };
+};