#!/bin/sh
### BEGIN INIT INFO
# Provides:          ec2-init
# Required-Start:    $network $local_fs $ssh
# Required-Stop:
# Should-Start:      $named
# Should-Stop:
# Default-Start:     S
# Default-Stop:      1
# Short-Description: Initialises system for use on Amazon EC2
# Description:       Fetches login credentials and handles various quirks
### END INIT INFO

PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
NAME=ec2-init

. /lib/lsb/init-functions

if [ ! -d /var/ec2 ]; then
    mkdir /var/ec2
fi

run_once() {
    per_id=$1
    action_id=$2

    semaphore="/var/lib/ec2/$action_id.$per_id"

    if ! [ -e "$semaphore" ]
    then
        touch "$semaphore"
        return 0
    fi
    return 1
}

run_once_per_ami() {
    action_id=$1
    ami=`ec2-get-info --ami-id | cut -f2 -d\ `
    run_once $ami $action_id
}

run_once_ever() {
    action_id=$1
    run_once ever $action_id
}

regenerate_ssh_host_keys() {
    rm -f /etc/ssh/ssh_host_*_key*

    ssh-keygen -f /etc/ssh/ssh_host_rsa_key -t rsa -N '' | logger -s -t "ec2"
    ssh-keygen -f /etc/ssh/ssh_host_dsa_key -t dsa -N '' | logger -s -t "ec2"

    # This allows user to get host keys securely through console log
    echo | logger -s -t "ec2"
    echo | logger -s -t "ec2"
    echo "#############################################################" | logger -s -t "ec2"
    echo "-----BEGIN SSH HOST KEY FINGERPRINTS-----" | logger -s -t "ec2"
    ssh-keygen -l -f /etc/ssh/ssh_host_rsa_key.pub | logger -s -t "ec2"
    ssh-keygen -l -f /etc/ssh/ssh_host_dsa_key.pub | logger -s -t "ec2"
    echo "-----END SSH HOST KEY FINGERPRINTS-----" | logger -s -t "ec2"
    echo "#############################################################" | logger -s -t "ec2"
}

case "$1" in
    start)
        log_daemon_msg "Waiting for EC2 meta-data service"
        if ec2-wait-for-meta-data-service
        then
            log_end_msg 0
        else
            log_end_msg 1
            exit 1
        fi

        if run_once_per_ami ssh_host_key_regeneration
        then
            regenerate_ssh_host_keys
        fi

        if run_once_ever ec2-defaults
        then
            log_daemon_msg "Setting EC2 defaults"
            if ec2-set-defaults 2> /dev/null
            then
                log_end_msg 0
            else
                log_end_msg 1
            fi
        fi

        if run_once_per_ami ssh_authorized_keys
        then
            log_daemon_msg "Fetching EC2 SSH keys"
            if ec2-fetch-credentials 2> /dev/null
            then
                log_end_msg 0
            else
                log_end_msg 1
            fi
        fi

        log_daemon_msg "Setting hostname to EC2 localhostname"
        if ec2-set-hostname 2> /dev/null
        then
            log_end_msg 0
        else
            log_end_msg 1
        fi

        if run_once_per_ami user-data
        then
            log_daemon_msg "Running EC2 user data"
            if ec2-run-user-data 2>&1 | logger -t "user-data"
            then
                log_end_msg 0
            else
                log_end_msg 1
            fi
        fi
        ;;
    stop)
        exit 0
        ;;
    restart|force-reload)
        exec $0 start
        ;;
    *)
        N=/etc/init.d/$NAME
        echo "Usage: $N {start|stop|force-stop|restart|force-reload|status}" >&2
        exit 1
        ;;
esac

exit 0