Return of the Yo notifications

Last time, took our first steps to notify our users about updates in a slight nicer way. This time we are going to modify our script so that our users are only bugged once a day, and also not promoted to install 10.11 if they’re already running it.

Unfortunately for some, whilst this will be possible if we stuck to using bash, it would drive me insane, so we are switching to Python. Don’t be scared! Python makes a lot of sense once you get your head around it, and you’ll be a much happier mac admin once you leave the 1500 line bash scripts behind.

First off, let’s get to the point we were at last time in python. Replace payload/opt/grahamgilbert/bin/updatenotifier with this (remember you can test your script as you’re going along by calling the script manually: $ payload/opt/grahamgilbert/bin/updatenotifier):

payload/opt/grahamgilbert/bin/updatenotifier
#!/usr/bin/python
import subprocess
def run_yo(title, text, url):
cmd = [
'/Applications/Utilities/yo.app/Contents/MacOS/yo',
'--title',
title,
'--info',
text,
'--action-btn',
'More Info',
'--action-path',
url
]
subprocess.call(cmd)
def main():
run_yo(url='munki://detail-InstallElCap',
title='Operating System Update',
text='Your Mac is out of date, '\
'please upgrade ASAP.')
if __name__ == '__main__':
main()

So the first thing we’re going to change is adding in a method to track when the user has seen our notification. We’re going to use macOS’ built in method for storing preferences - whilst not technically a preference, we are storing a value we want to persist across reboots, so a preferences makes perfect sense. Make payload/opt/grahamgilbert/bin/updatenotifier look the the code below.

payload/opt/grahamgilbert/bin/updatenotifier
#!/usr/bin/python
import datetime
import subprocess
import time
from Foundation import *
BUNDLE_ID = 'com.grahamgilbert.updatenotifier'
def run_yo(title, text, url):
cmd = [
'/Applications/Utilities/yo.app/Contents/MacOS/yo',
'--title',
title,
'--info',
text,
'--action-btn',
'More Info',
'--action-path',
url
]
subprocess.call(cmd)
def set_pref(pref_name, pref_value):
CFPreferencesSetAppValue(pref_name, pref_value, BUNDLE_ID)
CFPreferencesAppSynchronize(BUNDLE_ID)
def pref(pref_name):
default_prefs = {
# 'last_shown' : NSDate.new(),
}
pref_value = CFPreferencesCopyAppValue(pref_name, BUNDLE_ID)
if pref_value == None:
pref_value = default_prefs.get(pref_name)
# we're using a default value. We'll write it out to
# /Library/Preferences/<BUNDLE_ID>.plist for admin
# discoverability
set_pref(pref_name, pref_value)
if isinstance(pref_value, NSDate):
# convert NSDate/CFDates to strings
pref_value = str(pref_value)
return pref_value
def run_today():
# Has the preference ever been set? If not, this this the first time
# the script has ever run, so obviously they've not see it today
last_shown = pref('last_shown')
if last_shown == None:
return False
# Convert the last shown timestamp to a date we can work with
last_shown = datetime.datetime.fromtimestamp(int(last_shown))
# Get today's date
now = datetime.datetime.now()
# Get the time delta between now and 23 hours ago
day_ago = now - datetime.timedelta(hours=23)
# Python can work out which one is bigger - go python!
if last_shown > day_ago:
print 'Last shown within last 23 hours'
return True
else:
print 'Not shown with last 23 hours'
return False
def set_run_today():
now = int(time.time())
set_pref('last_shown', now)
def main():
if run_today() == False:
# This sets the preference with the current unix timestamp
set_run_today()
# And call Yo with our options
run_yo(url='munki://detail-InstallElCap',
title='Operating System Update',
text='Your Mac is out of date, '\
'please upgrade ASAP.')
if __name__ == '__main__':
main()

The final step is to only limit this to machines that need it - those under 10.11. We would usually use Munki to restrict who gets this, but just in case it gets manually installed somehow, let’s protect ourselves.

payload/opt/grahamgilbert/bin/updatenotifier
#!/usr/bin/python
import datetime
import platform
import subprocess
import time
from Foundation import *
BUNDLE_ID = 'com.grahamgilbert.updatenotifier'
def run_yo(title, text, url):
cmd = [
'/Applications/Utilities/yo.app/Contents/MacOS/yo',
'--title',
title,
'--info',
text,
'--action-btn',
'More Info',
'--action-path',
url
]
subprocess.call(cmd)
def set_pref(pref_name, pref_value):
CFPreferencesSetAppValue(pref_name, pref_value, BUNDLE_ID)
CFPreferencesAppSynchronize(BUNDLE_ID)
def pref(pref_name):
default_prefs = {
# 'last_shown' : NSDate.new(),
}
pref_value = CFPreferencesCopyAppValue(pref_name, BUNDLE_ID)
if pref_value == None:
pref_value = default_prefs.get(pref_name)
# we're using a default value. We'll write it out to
# /Library/Preferences/<BUNDLE_ID>.plist for admin
# discoverability
set_pref(pref_name, pref_value)
if isinstance(pref_value, NSDate):
# convert NSDate/CFDates to strings
pref_value = str(pref_value)
return pref_value
def run_today():
# Has the preference ever been set? If not, this this the first time
# the script has ever run, so obviously they've not see it today
last_shown = pref('last_shown')
if last_shown == None:
return False
# Convert the last shown timestamp to a date we can work with
last_shown = datetime.datetime.fromtimestamp(int(last_shown))
# Get today's date
now = datetime.datetime.now()
# Get the time delta between now and 23 hours ago
day_ago = now - datetime.timedelta(hours=23)
# Python can work out which one is bigger - go python!
if last_shown > day_ago:
print 'Last shown within last 23 hours'
return True
else:
print 'Not shown with last 23 hours'
return False
def set_run_today():
now = int(time.time())
set_pref('last_shown', now)
def main():
# platform.mac_ver() gives us ('10.11', ('', '', ''), 'x86_64')
# so the first part is useful here
mac_version = platform.mac_ver()[0]
if run_today() == False and (mac_version.startswith('10.10') \
or mac_version.startswith('10.9')):
# This sets the preference with the current unix timestamp
set_run_today()
# And call Yo with our options
run_yo(url='munki://detail-InstallElCap',
title='Operating System Update',
text='Your Mac is out of date, '\
'please upgrade ASAP.')
if __name__ == '__main__':
main()

All that’s left now is to rebuild the package.

$ pkgbuild --root payload --identifier com.grahamgilbert.updatenotifier --version 1.1.0 ~/Desktop/UpdateNotifier.pkg