'Deploy to heroku' fails with Application Error, App crahshed

Logs

2016-05-22T20:34:28.911247+00:00 heroku[web.1]: State changed from crashed to starting
2016-05-22T20:34:43.130790+00:00 heroku[web.1]: Starting process with command `node keystone.js`
2016-05-22T20:34:45.412256+00:00 app[web.1]: { [Error: ENOENT: no such file or directory, open '.env'] errno: -2, code: 'ENOENT', syscall: 'open', path: '.env' }
2016-05-22T20:34:48.943331+00:00 app[web.1]: { [Error: Cannot find module '../build/Release/bson'] code: 'MODULE_NOT_FOUND' }
2016-05-22T20:34:48.943687+00:00 app[web.1]: js-bson: Failed to load c++ bson extension, using pure JS version
2016-05-22T20:34:49.536957+00:00 app[web.1]: ------------------------------------------------
2016-05-22T20:34:49.536976+00:00 app[web.1]: Mongo Error:
2016-05-22T20:34:49.536983+00:00 app[web.1]: 
2016-05-22T20:34:49.537300+00:00 app[web.1]: [Error: failed to connect to [localhost:27017]]
2016-05-22T20:34:49.539686+00:00 app[web.1]: /app/node_modules/keystone/lib/core/mount.js:630
2016-05-22T20:34:49.539694+00:00 app[web.1]:            throw new Error('KeystoneJS (' + keystone.get('name') + ') failed to start');
2016-05-22T20:34:49.539695+00:00 app[web.1]:            ^
2016-05-22T20:34:49.539695+00:00 app[web.1]: 
2016-05-22T20:34:49.539696+00:00 app[web.1]: Error: KeystoneJS (KeystoneJS) failed to start
2016-05-22T20:34:49.539697+00:00 app[web.1]:     at NativeConnection.<anonymous> (/app/node_modules/keystone/lib/core/mount.js:630:10)
2016-05-22T20:34:49.539697+00:00 app[web.1]:     at emitOne (events.js:90:13)
2016-05-22T20:34:49.539698+00:00 app[web.1]:     at NativeConnection.emit (events.js:182:7)
2016-05-22T20:34:49.539698+00:00 app[web.1]:     at NativeConnection.Connection.error (/app/node_modules/mongoose/lib/connection.js:389:8)
2016-05-22T20:34:49.539699+00:00 app[web.1]:     at /app/node_modules/mongoose/lib/connection.js:416:14
2016-05-22T20:34:49.539700+00:00 app[web.1]:     at /app/node_modules/mongoose/lib/drivers/node-mongodb-native/connection.js:57:21
2016-05-22T20:34:49.539701+00:00 app[web.1]:     at /app/node_modules/mongoose/node_modules/mongodb/lib/mongodb/db.js:286:18
2016-05-22T20:34:49.539701+00:00 app[web.1]:     at /app/node_modules/mongoose/node_modules/mongodb/lib/mongodb/db.js:365:7
2016-05-22T20:34:49.539702+00:00 app[web.1]:     at _combinedTickCallback (internal/process/next_tick.js:67:7)
2016-05-22T20:34:49.539705+00:00 app[web.1]:     at process._tickCallback (internal/process/next_tick.js:98:9)
2016-05-22T20:34:50.542000+00:00 heroku[web.1]: Process exited with status 1
2016-05-22T20:34:50.589663+00:00 heroku[web.1]: State changed from starting to crashed

I usedDeploy to Heroku button

I deployed the app twice, both times got same error.

I was able to remove the following errors: Removed this error { [Error: ENOENT: no such file or directory, open '.env'] errno: -2, code: 'ENOENT', syscall: 'open', path: '.env' } by removing the .env file from .gitignore.

Lost js-bson: Failed to load c++ bson extension, using pure JS version error by changing node_modules/bson/ext line 19 to just bson = require('bson')

Application Error still persists when I open the app page on heroku

[q3e]

Finally fixed it you have to make sure that when you create addon for mongolab, then the key to the config that Heroku sets automatically is MONGOLAB_URL.. The default is MONGODB_URI

Thanks

[sylvery]

Go to your heroku dashboard and reveal your app’s config variables on the app’s settings page. There you’ll notice that the mongolab mongodb connection string has the key MONGODB_URI. What I did was copy the value of the key and then deleted the config variable. I then created a new variable MONGO_URI and pasted the value. The app automatically restarted and worked like magic since.