Shell script to use in a vagrant provisioning script to enable SSH agent forwarding

gistfile1.sh

#!/bin/bash
echo "Setting up agent forwarding..."
mkdir -p /root/.ssh
chmod 0700 /root/.ssh
echo "Host *\n    StrictHostKeyChecking no" >> /root/.ssh/config
chmod 0600 /root/.ssh/config
ppid=$PPID
found_auth_sock=""
while [[ $SSH_AUTH_SOCK == "" && $ppid != "1" ]]; do
    f=`ls /tmp/ssh*/agent.$ppid 2>/dev/null`
    if [[ -z "$f" ]]; then
        ppid=`cat /proc/$ppid/status | grep PPid | awk '{print $2}'`
    else
        export SSH_AUTH_SOCK="$f"
        echo "SSH_AUTH_SOCK=$SSH_AUTH_SOCK"
    fi
done
if [[ -z "$SSH_AUTH_SOCK" ]]; then
    echo "Could not find running ssh agent.\n" 1>&2
    exit 1
fi