After the struggles I’ve had over the last couple of days, it’s strangely reassuring to stumble on a problem I’ve actually *seen* before, and recently.  Firsthand even.

I’ve fresh-built a Debian 8.5.2 VM in Virtualbox via Vagrant.  Then I setup an Ansible inventory file to point to the box’s current vagrant ssh-config settings.  Then fired off the tried-and-true ansible connectivity test, ansible all -u vagrant -m ping.  Here’s the response:

127.0.0.1 | UNREACHABLE! => {
    "changed": false,
    "msg": "ERROR!  SSH encountered an unknown error during the connection.  We recommend you re-run the command using -vvvv, which will enable SSH debugging output to help diagnose the issue",
    "unreachable": true
}

Running the same command with -vvvv parameter results in a garbage heap of unformatted/concatenated debug screed, which ends with:

debug1: No more authentication methods to try.\r\nPermission denied (publickey,password).\r\n"

Simple Solution

As I’ve documented to myself already elsewhere, I need to run the following two commands:

ssh-keygen -t rsa

ssh-copy-id -p 2222 vagrant@127.0.0.1

Bingo!  Nice to get an easy win.