chore: split app into api and web

api/services/dns.js

@@ -0,0 +1,30 @@
+var dns = require('dns')
+
+function resolvePromise(hostname) {
+  return new Promise((resolve, reject) => {
+    dns.resolve4(hostname, function(err, addresses) {
+      if (err) return reject(err)
+      resolve(addresses)
+    })
+  })
+}
+
+module.exports = async (req, res) => {
+  const name = req.query.name
+
+  if (!name) {
+    return res.status(400).json({ error: 'no query given' })
+  }
+
+  try {
+    const response = await resolvePromise(name)
+    const availability = response && response.length > 0 ? false : true
+
+    res.json({ availability })
+  } catch (err) {
+    if (err.code === 'ENODATA') {
+      return res.status(200).json({ availability: true })
+    }
+    res.status(400).json({ error: err.message })
+  }
+}