Lambda function to check if specific tag do NOT exists-python

Question

I'm trying to get following:

Get all EC2 instances that either:

1. are Tagged with tag Owner and value Unknown or unknown
2. are missing tag Owner

I'm able to accomplish 1) but no idea how to get 2)

import boto3   
import collections     
import datetime     
import time     
import sys 

ec = boto3.client('ec2', 'eu-west-1')     
ec2 = boto3.resource('ec2', 'eu-west-1')     


def lambda_handler(event, context):           
    instance_ids = []
    reservations = ec.describe_instances(     
        Filters=[     
            {'Name': 'tag:Owner', 'Values': ['Unknown', 'unknown']},     
        ]     
    ).get('Reservations', []) 

    for reservation in reservations:
          instances = reservation['Instances']
          for instance in instances:
              instance_ids.append(instance['InstanceId'])

    print("Stopping instances: {}".format(','.join(instance_ids)))

Answer 1

Combining code from my question and @Rage answer i managed to get what i want

Thanks again RaGe !!

import boto3   
import collections     
import datetime     
import time     
import sys 

ses = boto3.client('ses')

email_from = 'Email'
email_to = 'Email'
email_cc = 'Email'
emaiL_subject = 'Subject'
email_body = 'Body'






ec = boto3.client('ec2', 'eu-west-1')     
ec2 = boto3.resource('ec2', 'eu-west-1')     
from datetime import datetime
from dateutil.relativedelta import relativedelta

#create date variables 

date_after_month = datetime.now()+ relativedelta(days=7)
#date_after_month.strftime('%d/%m/%Y')
today=datetime.now().strftime('%d/%m/%Y')






def lambda_handler(event, context): 
  #Get instances with Owner Taggs and values Unknown/known
    instance_ids = []
    reservations = ec.describe_instances().get('Reservations', []) 

    for reservation in reservations:
     for instance in reservation['Instances']:
        tags = {}
        for tag in instance['Tags']:
            tags[tag['Key']] = tag['Value']
        if not 'Owner' in tags or tags['Owner']=='unknown' or tags['Owner']=='Unknown':
              instance_ids.append(instance['InstanceId'])  

                #Check if "TerminateOn" tag exists:

              if 'TerminateOn' in tags:  
                  #compare TerminteOn value with current date
                    if tags["TerminateOn"]==today:

                    #Check if termination protection is enabled
                     terminate_protection=ec.describe_instance_attribute(InstanceId =instance['InstanceId'] ,Attribute = 'disableApiTermination')
                     protection_value=(terminate_protection['DisableApiTermination']['Value'])
                     #if enabled disable it
                     if protection_value == True:
                        ec.modify_instance_attribute(InstanceId=instance['InstanceId'],Attribute="disableApiTermination",Value= "False" )
                    #terminate instance 
                     ec.terminate_instances(InstanceIds=instance_ids)
                     print "terminated" + str(instance_ids)
                     #send email that instance is terminated

                    else: 
                    #Send an email to engineering that this instance will be removed X amount of days (calculate the date based on today's date and the termination date."

                      now=datetime.now()
                      future=tags["TerminateOn"]
                      TerminateOn = datetime.strptime(future, "%d/%m/%Y")
                      days= (TerminateOn-now).days
                      print str(instance_ids) +  " will be removed in "+ str(days) + " days"


              else: 
                 if not 'TerminateOn' in tags:#, create it  
                  ec2.create_tags(Resources=instance_ids,Tags=[{'Key':'TerminateOn','Value':date_after_month.strftime('%d/%m/%Y')}])
                  ec.stop_instances(InstanceIds=instance_ids)

                  print "was shut down "+format(','.join(instance_ids))

Answer 2

Like I said in the comment you want to forgo the Owner filter so your response includes instances without Owner tag as well, and then you get to filtering locally.

reservations = ec.describe_instances().get('Reservations', [])
for reservation in reservations:
    for instance in reservation['Instances']:
        tags = {}
        for tag in instance['Tags']:
            tags[tag['Key']] = tag['Value']

        if not 'Owner' in tags:
            print instance['InstanceId'] + " does not have Owner tag"
        elif tags['Owner'] in ['Unknown', 'unknown']:
            print instance['InstanceId'] + " has [U|u]nknown Owner tag"

If you have a large number of instances in your account, the response to describe_instances may be paginated, and you'll have to deal with that as well.