AWS Lambda to auto start stop Ec2 instance on schedule using python and boto3

Use this lambda function to auto start stop all Ec2 instances based on schedule from tags.


#Auto Shutodown - Start EC2 instances based on tags
import boto3
import os
import json
import croniter
import datetime
# Enter the region your instances are in. Include only the region without specifying Availability Zone; e.g., 'us-east-1'
region = 'us-west-2'

EC2_STATUS_CODE_RUNNING = 16
EC2_STATUS_CODE_STOPPED = 80

def lambda_handler(event, context):
ec2 = boto3.client(‘ec2’, region_name=region)

#auto_start_stop_tag = ‘tc:uptime_schedule_gmt’
auto_start_tag = ‘tc:start_time_schedule_gmt_24h_format’
auto_shutdown_tag = ‘tc:shutdown_time_schedule_gmt_24h_format’

instances_to_shutdown = []
instances_to_start = []
# Query ec2 machines for auto_start_stop_tag,
#instances_with_schedules = get_instance_schedules(auto_start_stop_tag)
instances_with_start_schedules = get_instance_schedules(auto_start_tag)
instances_with_shutdown_schedules = get_instance_schedules(auto_shutdown_tag)
print(“instances_with_start_schedules: %s” % instances_with_start_schedules)
print(“instances_with_shutdown_schedules: %s” % instances_with_shutdown_schedules)

for instance_id, values in instances_with_start_schedules.items():
now = datetime.datetime.now()
print(“now: %s” % now)
iterator = croniter.croniter(values[‘Schedule’], now)
next_run_time = iterator.get_next(datetime.datetime)
print(“next_run_time: %s” % next_run_time)
duration_until_next_run_time = next_run_time – now
print(“duration_until_next_start_time: %s” % duration_until_next_run_time)
duration_of_one_hour = datetime.timedelta(hours=1)

if duration_until_next_run_time <= duration_of_one_hour and values[‘State’][‘Code’] == EC2_STATUS_CODE_STOPPED: print(“true”) print(“instance_to_stop.append(%s)” % instance_id) instances_to_start.append(instance_id) for instance_id, values in instances_with_shutdown_schedules.items(): now = datetime.datetime.now() print(“now: %s” % now) iterator = croniter.croniter(values[‘Schedule’], now) next_run_time = iterator.get_next(datetime.datetime) print(“next_run_time: %s” % next_run_time) duration_until_next_run_time = next_run_time – now print(“duration_until_next_shutdown_time: %s” % duration_until_next_run_time) duration_of_one_hour = datetime.timedelta(hours=1) if duration_until_next_run_time <= duration_of_one_hour and values[‘State’][‘Code’] == EC2_STATUS_CODE_RUNNING: print(“instance_to_shutdown.append(%s)” % instance_id) instances_to_shutdown.append(instance_id) if len(instances_to_shutdown) > 0:
ec2.stop_instances(InstanceIds=instances_to_shutdown)
print(‘stopped your instances: ‘ + str(instances_to_shutdown))
send_shutdown_notification(instances_to_shutdown, “STOPPED”)

if len(instances_to_start) > 0:
ec2.start_instances(InstanceIds=instances_to_start)
print(‘started your instances: ‘ + str(instances_to_start))
send_start_notification(instances_to_start, “STARTED”)

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def send_shutdown_notification(instances, event):
instances_json_object = {“instances”:instances, “event”:event}
instances_json_string = json.dumps(instances_json_object)
instances_json_bytes = instances_json_string.encode(‘utf-8’)

lambda_arn = os.environ[‘LAMBDA_NOTIFICATION_SHUTDOWN_ARN’]
lambda_client = boto3.client(“lambda”)
lambda_client.invoke(
FunctionName=lambda_arn,
InvocationType=’Event’,
LogType=’None’,
Payload=instances_json_bytes
)

def send_start_notification(instances, event):
instances_json_object = {“instances”:instances, “event”:event}
instances_json_string = json.dumps(instances_json_object)
instances_json_bytes = instances_json_string.encode(‘utf-8’)

lambda_arn = os.environ[‘LAMBDA_NOTIFICATION_START_ARN’]
lambda_client = boto3.client(“lambda”)
lambda_client.invoke(
FunctionName=lambda_arn,
InvocationType=’Event’,
LogType=’None’,
Payload=instances_json_bytes
)

def get_instance_schedules(tag_name):
# When passed a tag key, tag value this will return a list of InstanceIds that were found.

ec2client = boto3.client(‘ec2’)

response = ec2client.describe_instances(
Filters=[
{
‘Name’: ‘tag-key’,
‘Values’: [tag_name]
}
]
)
instancelist = {}
for reservation in (response[“Reservations”]):
for instance in reservation[“Instances”]:
tag_value = ”
for tag in instance[‘Tags’]:
if tag[‘Key’] == tag_name:
tag_value = tag[‘Value’]
break
instancelist[instance[“InstanceId”]] = {‘Schedule’:tag_value,’State’:instance[‘State’]}

return instancelist