Example of the Python code to catch EC2 termination signal and ping Jenkins to run termination job. Useful to execute graceful shutdown if you’re using EC2 spot instaces.
You will need Jenkins Generic Webhook plugin.
import json
import boto3
import urllib3
import os
JENKINS_JOB_TOKEN = os.environ.get('JENKINS_TOKEN')
JENKINS_URL = os.environ.get('JENKINS_URL')
def invoke_jenkins(target):
http = urllib3.PoolManager()
return http.request('POST', f"{JENKINS_URL}/generic-webhook-trigger/invoke?instance={target}", headers={'Authorization': f"Bearer {JENKINS_JOB_TOKEN}"})
def find_target(instance_id):
ec2 = boto3.client("ec2")
tags = ec2.describe_tags(Filters=[{'Name': 'resource-id', 'Values': [instance_id]}])
for tag in tags['Tags']:
if tag['Key'] == "Name":
return tag['Value']
def lambda_handler(event, context):
instance_id = event["detail"]["instance-id"]
target = find_target(instance_id)
if not target:
return {
'statusCode': 422,
'body': f"target for {instance_id} not found"
}
print(f"Jenkins termination job called for instance: {instance_id} target {target}")
resp = invoke_jenkins(target)
print(f"Jenkins response status {resp.status}")
print(f"Jenkins decoded response")
print(resp.data.decode('utf-8'))
return {
'statusCode': resp.status,
'body': json.dumps(resp.data.decode('utf-8'))
}