improve sentry reporting, add metrics for hydro

lib/hydro.js

@@ -1,5 +1,10 @@
 const crypto = require('crypto')
 const fetch = require('node-fetch')
+const statsd = require('../lib/statsd')
+
+const hydroStats = statsd.childClient({
+  prefix: 'hydro.'
+})
 
 const SCHEMAS = {
   page: 'docs.v0.PageEvent',
@@ -62,7 +67,7 @@ module.exports = class Hydro {
     })
     const token = this.generatePayloadHmac(body)
 
-    return fetch(this.endpoint, {
+    const fn = () => fetch(this.endpoint, {
       method: 'POST',
       body,
       headers: {
@@ -71,5 +76,12 @@ module.exports = class Hydro {
         'X-Hydro-App': 'docs-production'
       }
     })
+
+    const res = await hydroStats.asyncTimer(fn, 'response_time')
+
+    hydroStats.increment(`response_code.${res.statusCode}`, 1)
+    hydroStats.increment('response_code.all', 1)
+
+    return res;
   }
 }