Files
patroni/scripts/aws.py
T

73 lines
2.5 KiB
Python
Executable File

#!/usr/bin/python
import logging
import requests
from requests.exceptions import RequestException
import sys
import boto.ec2
logger = logging.getLogger(__name__)
class AWSConnection:
def __init__(self, cluster_name):
self.available = False
self.cluster_name = cluster_name if cluster_name is not None else 'unknown'
try:
# get the instance id
r = requests.get('http://169.254.169.254/latest/dynamic/instance-identity/document', timeout=0.1)
except RequestException:
logger.info("cannot query AWS meta-data")
return
if r.ok:
try:
content = r.json()
self.instance_id = content['instanceId']
self.region = content['region']
except Exception as e:
logger.info('unable to fetch instance id and region from AWS meta-data: {}'.format(e))
return
self.available = True
def aws_available(self):
return self.available
def _tag_ebs(self, role):
""" set tags, carrying the cluster name, instance role and instance id for the EBS storage """
if not self.available:
return False
tags = {'Name': 'spilo_' + self.cluster_name, 'Role': role, 'Instance': self.instance_id}
try:
conn = boto.ec2.connect_to_region(self.region)
volumes = conn.get_all_volumes(filters={'attachment.instance-id': self.instance_id})
conn.create_tags([v.id for v in volumes], tags)
except Exception as e:
logger.info('could not set tags for EBS storage devices attached: {}'.format(e))
return False
return True
def _tag_ec2(self, role):
""" tag the current EC2 instance with a cluster role """
if not self.available:
return False
tags = {'Role': role}
try:
conn = boto.ec2.connect_to_region(self.region)
conn.create_tags([self.instance_id], tags)
except Exception as e:
logger.info("could not set tags for EC2 instance {}: {}".format(self.instance_id, e))
return False
return True
def on_role_change(self, new_role):
ret = self._tag_ec2(new_role)
return self._tag_ebs(new_role) and ret
if __name__ == '__main__':
if len(sys.argv) == 4 and sys.argv[1] in ('on_start', 'on_stop', 'on_role_change'):
AWSConnection(cluster_name=sys.argv[3]).on_role_change(sys.argv[2])
else:
sys.exit("Usage: {0} action role name".format(sys.argv[0]))