How to filter tag values of an Ec2 Instance by a date in Boto3 - amazon-web-services

Question

I am trying to get instances that have tag name 'ttl' and tag values 'older than today'.
Our users tag their instances based on a future date (yyyy.mm.dd) so that the script should not automatically delete them before that date. The filter below should be able to get only instances whose tag-value is smaller than today's date. Is there a way to filter the tage values based on this logic -> get me instances that are < today ?
today = = datetime.today().strftime('%Y.%m.%d')
filters = [{'Name': 'tag:ttl','Values': ['<today']},{'Name': 'instance-state-name','Values': ['running']}]
The full code looks like this:
import boto3
import logging
#setup simple logging for INFO
logger = logging.getLogger()
logger.setLevel(logging.INFO)
#define the connection
ec2 = boto3.resource('ec2')
def lambda_handler(event, context):
filters = [{'Name': 'tag:ttl','Values': ['<today']},{'Name': 'instance-state-name','Values': ['running']}]
#locate all running instances
RunningInstances = [instance.id for instance in instances]
print (RunningInstances)
#make sure there are actually instances to shut down.
if len(RunningInstances) > 0:
shuttingDown = ec2.instances.filter(InstanceIds=RunningInstances).stop()
print "shuttingDown"
else:
print "Nothing to see here"

Answer 1

You can't compare dates in the query as you specified. You need to write some code comparing the dates in your python script and take action. Roughly like below:
import datetime
import boto3
# Connect to EC2
ec2 = boto3.resource('ec2')
def get_ttl(instance):
for tag in instance.tags:
if 'ttl'in tag['Key']:
ttl = tag['Value']
return ttl
def lambda_handler(event,context):
running_instances = ec2.instances.filter(Filters=[{
'Name': 'instance-state-name',
'Values': ['running']}])
for instance in running_instances:
ttl = get_ttl(instance)
if ttl:
if datetime.date.today() > datetime.datetime.strptime(ttl, "%Y-%m-%d").date():
print('stopping instance')
else:
print("nothing to do here")
Basically, it resolves around comparing dates
In [30]: datestring = '2021-02-22'
In [31]: datetime.date.today() == datetime.datetime.strptime(datestring, "%Y-%m-%d").date()
Out[31]: False
In [32]: datetime.date.today() < datetime.datetime.strptime(datestring, "%Y-%m-%d").date()
Out[32]: True
In [33]: datetime.date.today() > datetime.datetime.strptime(datestring, "%Y-%m-%d").date()
Out[33]: False