A quick python script to generate Ansible inventory lines from the Vagrant ssh-config. Note that you must have run `vagrant up` at least once to ensure that the ports are properly assigned.

print_vagrant_inventory.py

import subprocess
import shlex
import sys
import os

# Define function to print a single ansible inventory line from a dictionary of ssh-config values.
def printInventoryLine(host):
    print ("{0} ansible_ssh_host={1} ansible_ssh_port={2} " +
        "ansible_ssh_private_key_file={3} ansible_ssh_user={4}"
    ).format(host["Host"], host["HostName"], host["Port"], host["IdentityFile"], host["User"])

# Ensure script was run from a directory where running vagrant will do something
if (not os.path.isfile('Vagrantfile')):
    sys.exit('ERROR: Please run this script from the directory containing your Vagrantfile')

# Run vagrant ssh-config to get connection info for each server
process = subprocess.Popen(['vagrant', 'ssh-config'], shell=False, stdout=subprocess.PIPE)

# Lex the result into tokens, allowing paths and ip-addresses as single tokens
lexer = shlex.shlex(process.communicate()[0])
lexer.wordchars += './'

# Parse the tokens
server = None
while True:
    # Get next token
    token = lexer.get_token()

    # At the end of the token stream
    if not token:
        # Print final ansible line if at least one server was parsed
        if server is not None:
            printInventoryLine(server)
        break
    
    # Parse a key-value pair
    if (token == "Host"):
        # Reset the buffered server, and print if this is not the first Host token we have seen.
        if server is not None:
            printInventoryLine(server)
        server = {}

    server[token] = lexer.get_token()