Using an SSH keyfile with Fabric

Question

How do you configure fabric to connect to remote hosts using SSH keyfiles (for example, Amazon EC2 instances)?

Answer 1

I had to do this today, my .py file was as simple as possible, like the one posted in the answer of @YuvalAdam but still I kept getting prompted for a password...

Looking at the paramiko (the library used by fabric for ssh) log, I found the line:

Incompatible ssh peer (no acceptable kex algorithm)

I updated paramiko with:

sudo pip install paramiko --upgrade

And now it's working.