Ruby on Rails MongoDB existing dataset - ruby-on-rails

Question

I have a RoR application which will read info from a MongoDB collection.
I have my model set as:-
class Vulnerability
include Mongoid::Document
field :id, type: String
field :description, type: String
field :type, type: String
end
The first record in the collection is formatted like this:-
> db.vulnerabilities.findOne()
{
"_id" : "NGINX:CVE-2009-3896",
"_index" : "bulletins",
"_type" : "bulletin",
"_score" : null,
"_source" : {
"lastseen" : "2016-09-26T17:22:32",
"references" : [ ],
"edition" : 1,
"description" : "Null pointer dereference vulnerability\nSeverity: major\nCVE-2009-3896\nNot vulnerable: 0.8.14+, 0.7.62+, 0.6.39+, 0.5.38+\nVulnerable: 0.1.0-0.8.13",
"reporter" : "Nginx",
"published" : "2009-11-24T12:30:00",
"type" : "nginx",
"title" : "Null pointer dereference vulnerability",
"bulletinFamily" : "software",
"affectedSoftware" : [
{
"name" : "nginx",
"version" : "0.8.13",
"operator" : "le"
}
],
"cvelist" : [
"CVE-2009-3896"
],
"modified" : "2009-11-24T12:30:00",
"id" : "NGINX:CVE-2009-3896",
"href" : "http://nginx.org/en/security_advisories.html",
"cvss" : {
"score" : 5,
"vector" : "AV:NETWORK/AC:LOW/Au:NONE/C:NONE/I:NONE/A:PARTIAL/"
}
},
"sort" : [
38985
]
}
I want to pull the ID, the type and the description. When trying to view the index view I get
NameError at /vulnerabilities uninitialized constant Bulletin
I believe the issue is with the type in the document as there is a key of _type but I want to get the type from the key _source, so in the example above it will display nginx not bulletin.