I'm trying to level up my devops skills and I've got a simple 'hello world' rails app on a single Digital Ocean Droplet that uses ubuntu and ngninx. I'm trying to better understand how / where to use credentials using the ssh comment you said. Any chance you could link me to an example of how to do the SSH method of management? What would be some examples of shared location to store the master key? (If that doesn't make sense, I'll try to clarify)
Just a note for anyone else that might get an error about it not being able to find master.key. Make sure you are in the root directory of your app. I was in the config directory on the command line and it took me a bit to realize what the problem was. I think the command should be updated to check what directory it is being called from. Anyway, once I solved that riddle your directions worked great!