headlessRPiNotes.txt

HOW TO SET UP RPi FOR HEADLESS ON A SIMPLE/HOME NETWORK...

-After flashing the OS onto the SD card, navigate into the 'boot' folder, 
and add two new text files:

	-ssh  (add a new text doc; change the name to "ssh" with no file extension
	-wpa_supplicant.conf  (don't forget to change the extension to .conf)


-This is the bit to include in the wpa_supplicant.conf file:

country=US
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
	ssid="Actress"
	psk="inventor"
	key_mgmt=WPA-PSK
}


-I think when this boots for the first time in the RPi, it notices the two files 
that were created and then uses those as signals to make changes to the normal 
configuration files.

-After you boot the RPi once, if you pull the card and jam it back in a card-reader 
on a laptop, you will notice that the 'ssh' and 'wpa_supplicant.conf' files are now 
gone. It would seem that after those files are used as previously described, the RPi
then tidys-up. It would be interesting to run some tests to see if the changes that
are made by those files are permanent, or if the RPi reverts to its non-headless config.
It would also be interesting to see if you can make changes to the 'wpa_supplicant' 
configuration by creating a new file with different parameters... (insert thoughtful 
emoticon here).

-You SHOULDN'T (should being the least-useful word in the English language...)
need to know the IP address of the RPi. It SHOULD boot with 'raspberrypi' as the 
host name by which it is identified by the network. So even if the router assigns
the RPi a random IP address dynamically, you SHOULD be able to talk to the RPi by
simply referring to it as either 'raspberrypi' or 'raspberrypi.local'. That said, half the
time neither of these worked, and I had to SSH in using "pi@192.168.2.13" I pulled the 
correct IP address by accessing the admin controls for my home rounter. Not a viable 
solution in the 'eduroam' world...

-After I successfully managed to ssh-in to the headless Pi, I used 'raspi-config'
to ensure that ssh had been activated. I also changed the netowrk hostname to 'headlessRPi'
so that I can make sure I know who I'm talking to. Leaving the hostname as 'raspberrypi'
can get confusing because the router seems to create a profile for each new device,
and when I start over and re-flash the basic disk-image, it is like you are creating yet
another new device. I also changed the password to 'headless' These changes also helps 
to avoid the issue of thinking you are ssh-ing in to one RPi device, when you are in fact
dialing into a different one (Sam and Aaron had a good time watching the WRONG computer
dutifully run its shutdown sequence as commanded...)




HOW TO SET UP RPi FOR HEADLESS ON A WPA2-ENTERPRISE NETWORK (AKA-eduroam)...

-Same basic approah at the start...

-After flashing the OS onto the SD card, navigate into the 'boot' folder, 
and add two new text files:

	-ssh  (add a new text doc; change the name to "ssh" with no file extension
	-wpa_supplicant.conf  (don't forget to change the extension to .conf)


-This is the bit to include in the wpa_supplicant.conf file (a bit different from above):

country=US
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
	ssid="eduroam"
	# psk="aVeryStrongPassword"
	key_mgmt=WPA-EAP
	eap=PEAP
	identity="sshanks@d.umn.edu"
	password="MyVeryStrongPassword6"
}


SET UP THE PI TO EMAIL YOU ITS IP ADDRESS:

Create the Python Script
Copy and paste the following code into a text editor (I'm a Vim man myself (fun with Nano?).

'''
__author__ = 'Cody Giles'
__license__ = "Creative Commons Attribution-ShareAlike 3.0 Unported License"
__version__ = "1.0"
__maintainer__ = "Cody Giles"
__status__ = "Production"
'''
import subprocess
import smtplib
from email.mime.text import MIMEText
import datetime

def connect_type(word_list):
    """ This function takes a list of words, then, depeding which key word, returns the corresponding
    internet connection type as a string. ie) 'ethernet'.
    """
    if 'wlan0' in word_list or 'wlan1' in word_list:
        con_type = 'wifi'
    elif 'eth0' in word_list:
        con_type = 'ethernet'
    else:
        con_type = 'current'

    return con_type

# Change to your own account information
# Account Information
to = 'sshanks@d.umn.edu' # Email to send to.
gmail_user = 'sshanks@d.umn.edu' # Email to send from. (MUST BE GMAIL)
gmail_password = 'Pythonisthebest!' # Gmail password.
smtpserver = smtplib.SMTP('smtp.gmail.com', 587) # Server to use.

smtpserver.ehlo()  # Says 'hello' to the server
smtpserver.starttls()  # Start TLS encryption
smtpserver.ehlo()
smtpserver.login(gmail_user, gmail_password)  # Log in to server
today = datetime.date.today()  # Get current time/date

arg='ip route list'  # Linux command to retrieve ip addresses.
# Runs 'arg' in a 'hidden terminal'.
p=subprocess.Popen(arg,shell=True,stdout=subprocess.PIPE)
data = p.communicate()  # Get data from 'p terminal'.
print(data)
# Split IP text block into three, and divide the two containing IPs into words.
ip_lines = data[0].splitlines()
split_line_a = ip_lines[1].split()
#split_line_b = ip_lines[2].split()

# con_type variables for the message text. ex) 'ethernet', 'wifi', etc.
ip_type_a = connect_type(split_line_a)
#ip_type_b = connect_type(split_line_b)

"""Because the text 'src' is always followed by an ip address,
we can use the 'index' function to find 'src' and add one to
get the index position of our ip.
"""
ipaddr_a = split_line_a[split_line_a.index('src')+1]
#ipaddr_b = split_line_b[split_line_b.index('src')+1]

# Creates a sentence for each ip address.
my_ip_a = 'The %s IP for your RaspberryPi is %s' % (ip_type_a, ipaddr_a)
#my_ip_b = 'Your %s ip is %s' % (ip_type_b, ipaddr_b)

# Creates the text, subject, 'from', and 'to' of the message.
#msg = MIMEText(my_ip_a + "\n" + my_ip_b)
msg = MIMEText(my_ip_a)
msg['Subject'] = 'IPs For RaspberryPi on %s' % today.strftime('%b %d %Y')
msg['From'] = gmail_user
msg['To'] = to
# Sends the message
smtpserver.sendmail(gmail_user, [to], msg.as_string())
# Closes the smtp server.
smtpserver.quit()







Save this script using a nice name like 'startup_mailer.py' and make note of its path (like /home/pi/Code/startup_mailer.py)

For good measure, make the script executable

sudo chmod +x startup_mailer.py


Not you need to edit /etc/rc.local as follows:

 sudo nano /etc/rc.local

Add the 'python /home/pi/Code/startup_mailer.py' line, so the file now looks like this:

 # rc.local
 #
 # This script is executed at the end of each multiuser runlevel.
 # Make sure that the script will "exit 0" on success or any other
 # value on error.
 #
 # In order to enable or disable this script just change the execution
 # bits.
 #
 # By default this script does nothing.
 # Print the IP address if it doesn't work ad sleep 30 before all your code 
 _IP=$(hostname -I) || true
 if [ "$_IP" ]; then
   printf "My IP address is %s\n" "$_IP"
   python /home/pi/Code/startup_mailer.py     <<<------------------------------------------ ADD THIS LINE!!!
 fi
 exit 0

FINISHED!
Reboot your Pi and you should receive an email with your ip address.