serverlesscurator.py

# Run Elasticsearch Curator from AWS Lambda.
#
# Edit serverless-curator.yaml to define which indices should be purged.
from __future__ import print_function

import os
import certifi
import curator
import yaml
import time
from curator.exceptions import NoIndices
from elasticsearch import Elasticsearch, RequestsHttpConnection
from requests_aws4auth import AWS4Auth


# This is the entry point where Lambda will start execution.
def handler(event, context):
    # For this function, we don't care about 'event' and 'context',
    # but they need to be in the function signature anyway.

    with open('serverless-curator.yaml') as config_file:
        config = yaml.load(config_file)

    # Create a place to track any indices that are deleted.
    deleted_indices = {}

    # Create a place to track backup indices
    backup_indices = {}

    # We can define multiple Elasticsearch clusters to manage, so we'll have
    # an outer loop for working through them.
    for cluster_config in config:
        cluster_name = cluster_config['name']
        deleted_indices[cluster_name] = []
        backup_indices[cluster_name] = []

        awsauth = AWS4Auth(os.getenv('AWS_ACCESS_KEY_ID'), os.getenv('AWS_SECRET_ACCESS_KEY'), cluster_config['region'], 'es', session_token=os.getenv('AWS_SESSION_TOKEN'))

        # Create a collection to the cluster. We're using mangaged clusters in
        # Elastic Cloud for this example, so we can enable SSL security.
        es = Elasticsearch(cluster_config['endpoint'], http_auth=awsauth, connection_class=RequestsHttpConnection)
        
        # Now we'll work through each set of time-series indices defined in our config for this cluster.
        for index in cluster_config['indices']:
            prefix = index['prefix']
            print('Checking "%s" indices on %s cluster.' %
                  (prefix, cluster_name))

            # Fetch all the index names.
            index_list = curator.IndexList(es)
            try:
                # Reduce the list to those that match the prefix.
                index_list.filter_by_regex(kind='prefix', value=prefix)
                # Reduce again, by age.
                index_list.filter_by_age(source='name', direction='older',
                                  timestring='%Y.%m.%d', unit='days',
                                  unit_count=index['days'])
                curator.DeleteIndices(index_list).do_action()
            # If nothing is left in the list, we'll get a NoIndices exception.
            # That's OK.
            except NoIndices:
                pass

            # Record the names of any indices we removed.
            deleted_indices[cluster_name].extend(index_list.working_list())

    lambda_response = {'backup': backup_indices, 'deleted': deleted_indices}
    print(lambda_response)
    return lambda_response