Heroku “no Cedar-supported app” when pushing, even though app is on cedar stack?

Question

I have never used Heroku before, but our client wants us to use it. An app is already set up on Heroku, and if I log in and check the app info it says that it is on the cedar stack.

Now I want to put some PHP files onto it. I've set up a remote, then used git init, add, commit, but when I try to use "git push heroku master" I get the error:

Heroku push rejected, no Cedar-supported app detected

I don't understand since the app has been set up as a cedar app? I've seen lots of people with the same error message, but all of the solutions seems to say it's something to do with gemfiles (I have no idea what they are), or to run git init again.

Does anyone have any other ideas on what the problem could be? I apologise if there isn't much info here, but as I say I've never used Heroku before, and have only used git for one other project (normally we use our own server which I can just drop PHP files into using a GUI).

Thanks

Answer 1

You need to have an index.php in the root for Heroku to detect the application type as PHP.