From 0815d7fc7f8ab3edf6fb2969f5904b60686feb51 Mon Sep 17 00:00:00 2001
From: "supa-creation.com" <contact@supa-creation.com>
Date: Sat, 4 Nov 2017 14:21:47 +0100
Subject: [PATCH] Add TTL index configuration

---
 lib/mongoCache.js | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/mongoCache.js b/lib/mongoCache.js
index 7156d72..dd5b1c2 100644
--- a/lib/mongoCache.js
+++ b/lib/mongoCache.js
@@ -4,11 +4,34 @@ var MongoClient = require('mongodb').MongoClient;
 var mongoUri = process.env.MONGOLAB_URI ||
     process.env.MONGOHQ_URL ||
     'mongodb://localhost/prerender';
+var mongoTtl = process.env.MONGODB_CACHE_TTL || null;
 
 var database;
 
-MongoClient.connect(mongoUri, function(err, db) {
+MongoClient.connect(mongoUri, function (err, db) {
     database = db;
+
+    if (mongoTtl) {
+        database.collection('pages', function (err, collection) {
+            collection.indexes(function (err, indexes) {
+                var existTtlIndex = false;
+
+                indexes.forEach(function (index) {
+                    var isTtlIndex = JSON.stringify(index.key) == JSON.stringify({created: 1});
+                    if (isTtlIndex && index.expireAfterSeconds == mongoTtl) {
+                        existTtlIndex = true;
+                    } else if (isTtlIndex) {
+                        collection.dropIndex(index.name);
+                    }
+                });
+
+                if (!existTtlIndex) {
+                    console.log('createIndex');
+                    collection.ensureIndex({"created": 1}, {expireAfterSeconds: mongoTtl});
+                }
+            });
+        });
+    }
 });
 
 var cache_manager = require('cache-manager');