mongodb (mongolab) on heroku. 'LoopBack connector "mongodb" is not installed' - node.js

Question

I have a nodejs app which runs fine locally. It uses mongodb. I wanted to push it to heroku, so I installed the mongolab addon, 'heroku addons:open mongolab'
and updated the datasources.json file like so;
{
"db": {
"name": "db",
"url": "mongodb://<user:<pwd>#ds037252.mongolab.com:37252/heroku_app37281512",
"connector": "mongodb"
}
}
When I push it to heroku, it fails on startup with the following;
2015-05-29T04:25:39.953257+00:00 heroku[web.2]: Starting process with command node tk/server/server.js 2015-05-29T04:25:41.167153+00:00 app[web.2]: Detected 512 MB available memory, 512 MB limit per process (WEB_MEMORY) 2015-05-29T04:25:41.167177+00:00 app[web.2]: Recommending WEB_CONCURRENCY=1 2015-05-29T04:25:42.158058+00:00 app[web.2]: 2015-05-29T04:25:42.158064+00:00 app[web.2]: 2015-05-29T04:25:42.158063+00:00 app[web.2]: WARNING: LoopBack connector "mongodb" is not installed as any of the following modules: 2015-05-29T04:25:42.158066+00:00 app[web.2]: ./connectors/mongodb 2015-05-29T04:25:42.158068+00:00 app[web.2]: loopback-connector-mongodb 2015-05-29T04:25:42.158069+00:00 app[web.2]: 2015-05-29T04:25:42.158072+00:00 app[web.2]: 2015-05-29T04:25:42.158070+00:00 app[web.2]: To fix, run: 2015-05-29T04:25:42.158073+00:00 app[web.2]: npm install loopback-connector-mongodb
How do I deal with this? Do I need to modify datasources.json somehow?
I am on a heroku free plan. Perhaps it doesn't include mongodb access?
Thanks in advance, Ryan
Here is the package.json;
{
"name": "tk",
"version": "1.0.0",
"main": "server/server.js",
"scripts": {
"pretest": "jshint ."
},
"dependencies": {
"compression": "^1.0.3",
"cors": "^2.5.2",
"errorhandler": "^1.1.1",
"loopback": "^2.14.0",
"loopback-boot": "^2.6.5",
"loopback-datasource-juggler": "^2.19.0",
"serve-favicon": "^2.0.1"
},
"optionalDependencies": {
"loopback-explorer": "^1.1.0"
},
"devDependencies": {
"jshint": "^2.5.6"
},
"repository": {
"type": "",
"url": ""
},
"description": "tk"
}

Answer 1

You're missing the loopback-connector-mongodbfrom your dependencies
Change your package.json to (remove my comment if copy/pasting!)
{
"name": "tk",
"version": "1.0.0",
"main": "server/server.js",
"scripts": {
"pretest": "jshint ."
},
"dependencies": {
"compression": "^1.0.3",
"cors": "^2.5.2",
"errorhandler": "^1.1.1",
"loopback": "^2.14.0",
"loopback-boot": "^2.6.5",
"loopback-datasource-juggler": "^2.19.0",
"loopback-connector-mongodb": "1.9.1", --note the addition of this line
"serve-favicon": "^2.0.1"
},
"optionalDependencies": {
"loopback-explorer": "^1.1.0"
},
"devDependencies": {
"jshint": "^2.5.6"
},
"repository": {
"type": "",
"url": ""
},
"description": "tk"
}
Note-
You can also use npm install loopback-connector-mongodb --save - which will install the package locally, and save the dependency to your package.json