Google oath2 access via Ruby, Rails and 'omniauth-google-oauth2'gem failing

Question

I am hooking up a Google Login to my Rails app. I've solved many little problems along the way but I am now stuck. Here's the story, briefly:

• Using omniauth-google-oauth2 gem in Ruby/Rails
• Created the 'app' in Googles developer console, and have the client and secret keys
• Code is updated "correctly" I think
• Deployed to Heroku
• Click the login button, takes me to the google login page, where I click on my account to log in there.
• Wheels spin, and then I see this error: "accessNotConfigured" -- "Access Not Configured. Please use Google Developers Console to activate the API for your project."
• I go back to the goolgle dev console and I can't find anything that has to do with activating my api for my project
• I do a ton of googling and see this is a common problem but solutions don't seem to apply. A common one is to use the ipv6 name instead of am ipv4 name which doesn't even make sense to me.

PS: here's the whole error block

{
2014-05-01T00:50:27.479501+00:00 app[web.1]:  "error": {
2014-05-01T00:50:27.479503+00:00 app[web.1]:   "errors": [
2014-05-01T00:50:27.479504+00:00 app[web.1]:    {
2014-05-01T00:50:27.479515+00:00 app[web.1]:     "domain": "usageLimits",
2014-05-01T00:50:27.479518+00:00 app[web.1]:     "reason": "accessNotConfigured",
2014-05-01T00:50:27.479520+00:00 app[web.1]:     "message": "Access Not Configured. Please use Google Developers Console to activate the API for your project."
2014-05-01T00:50:27.479522+00:00 app[web.1]:    }
2014-05-01T00:50:27.479523+00:00 app[web.1]:   ],
2014-05-01T00:50:27.479525+00:00 app[web.1]:   "code": 403,
2014-05-01T00:50:27.479527+00:00 app[web.1]:   "message": "Access Not Configured. Please use Google Developers Console to activate the API for your project."
2014-05-01T00:50:27.479529+00:00 app[web.1]:  }
2014-05-01T00:50:27.479530+00:00 app[web.1]: }
2014-05-01T00:50:27.479532+00:00 app[web.1]:
2014-05-01T00:50:27.308265+00:00 app[web.1]: I, [2014-05-01T00:50:27.308169 #2]  INFO -- omniauth: (google_oauth2) Callback phase initiate

Answer 1

I was having the same problem. You can go to your Google console select APIs. Find Google+ API and click enable API. That should fix your problem.

Answer 2

It turns out that you have to enable one API buried deep inside the list of APIs which is the one for G+. That seemed to solve my problem. It's not mentioned anywhere. But I bet that's because google has made changes and so the existing blog posts and so on don't reflect the latest latest.