AWS Keep Alive lambda function
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{ | |
"AWSTemplateFormatVersion": "2010-09-09", | |
"Description": "Keep alive functions", | |
"Resources": { | |
"LambdaPolicy": { | |
"Type": "AWS::IAM::ManagedPolicy", | |
"Properties": { | |
"PolicyDocument": { | |
"Version": "2012-10-17", | |
"Statement": [ | |
{ | |
"Action": [ | |
"logs:*" | |
], | |
"Effect": "Allow", | |
"Resource": "arn:aws:logs:*:*:*" | |
}, | |
{ | |
"Effect": "Allow", | |
"Action": [ | |
"lambda:InvokeFunction" | |
], | |
"Resource": [ | |
"*" | |
] | |
} | |
] | |
} | |
} | |
}, | |
"LambdaRole": { | |
"Type": "AWS::IAM::Role", | |
"Properties": { | |
"ManagedPolicyArns": [ | |
{ "Ref": "LambdaPolicy" } | |
], | |
"AssumeRolePolicyDocument": { | |
"Version": "2012-10-17", | |
"Statement": [ | |
{ | |
"Action": [ | |
"sts:AssumeRole" | |
], | |
"Effect": "Allow", | |
"Principal": { | |
"Service": [ | |
"lambda.amazonaws.com" | |
] | |
} | |
} | |
] | |
} | |
} | |
}, | |
"KeepAliveFunction": { | |
"Type" : "AWS::Lambda::Function", | |
"DependsOn": [ "LambdaRole" ], | |
"Properties" : { | |
"Code" : { | |
"S3Bucket": { "your.s3.bucket.with.functions" }, | |
"S3Key": "lambda/keep-alive-functions.zip" | |
}, | |
"Description" : "Keep alive lambda containers function", | |
"FunctionName" : "KeepAliveLambdaContainers", | |
"Handler" : "keep_alive_handler.handler", | |
"MemorySize" : 128, | |
"Role" : { "Fn::GetAtt": [ "LambdaRole", "Arn" ] }, | |
"Runtime" : "python2.7", | |
"Timeout" : "300" | |
} | |
}, | |
"ScheduledLambdaContainersKeepAliveRule": { | |
"Type": "AWS::Events::Rule", | |
"Properties": { | |
"Description": "ScheduledRule", | |
"ScheduleExpression": "rate(10 minutes)", | |
"State": "ENABLED", | |
"Targets": [{ | |
"Arn": { "Fn::GetAtt": ["KeepAliveFunction", "Arn"] }, | |
"Id": "KeepAliveFunction" | |
}] | |
} | |
}, | |
"PermissionForEventsToInvokeLambda": { | |
"Type": "AWS::Lambda::Permission", | |
"Properties": { | |
"FunctionName": { "Ref": "KeepAliveFunction" }, | |
"Action": "lambda:InvokeFunction", | |
"Principal": "events.amazonaws.com", | |
"SourceArn": { "Fn::GetAtt": ["ScheduledLambdaContainersKeepAliveRule", "Arn"] } | |
} | |
} | |
}, | |
"Outputs": { | |
"KeepAliveLambdaFunctionArn": { | |
"Description": "Keep alive lambda function ARN", | |
"Value": { "Fn::GetAtt": [ "KeepAliveFunction", "Arn" ] } | |
} | |
} | |
} |
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from __future__ import print_function | |
import boto3 | |
import logging | |
import json | |
import sys | |
from multiprocessing.pool import ThreadPool | |
from contextlib import closing | |
# | |
# Logging | |
# | |
class LessThanFilter(logging.Filter): | |
def __init__(self, exclusive_maximum, name=""): | |
super(LessThanFilter, self).__init__(name) | |
self.max_level = exclusive_maximum | |
def filter(self, record): | |
return int(record.levelno < self.max_level) | |
log = logging.getLogger() | |
log.setLevel(logging.INFO) | |
# Log to stdout < WARNING level | |
stdout = logging.StreamHandler(sys.stdout) | |
stdout.addFilter(LessThanFilter(logging.WARNING)) | |
stdout.setLevel(logging.DEBUG) | |
# Log to stderr >= WARNING level | |
stderr = logging.StreamHandler(sys.stderr) | |
stderr.setLevel(logging.WARNING) | |
log.addHandler(stdout) | |
log.addHandler(stderr) | |
# | |
# Configuration | |
# | |
with open("config/functions.json") as input: | |
config = json.load(input) | |
region = config.get("region", "eu-west-1") | |
# | |
# Keep alive handler | |
# | |
def ping_function(func): | |
try: | |
name = func["name"] | |
event = func["event"] | |
payload = json.dumps(event) | |
logging.info("Invoking function {}".format(name)) | |
client = boto3.client('lambda', region_name=region) | |
r = client.invoke(FunctionName=name, InvocationType="RequestResponse", Payload=payload) | |
if r.get("StatusCode", 0) != 200: | |
log.error("Failed to invoke {}, response: {}".format(name, r)) | |
return 0 | |
payload = json.loads(r["Payload"].read().decode("utf-8")) | |
if payload.get("statusCode", 0) != 200: | |
log.error("Invalid lambda {} response: {}".format(name, payload)) | |
return 0 | |
logging.info("Function {} invoked successfully".format(name)) | |
return 1 | |
except Exception as e: | |
logging.error("Failed to invoke {}, exception: {}".format(func, e)) | |
return 0 | |
def keep_alive_function(func): | |
try: | |
containers = func.get("containers", 1) | |
with closing(ThreadPool(containers)) as pool: | |
mp = pool.map_async(ping_function, [func] * containers) | |
_ = mp.get(300) | |
pool.terminate() | |
return containers | |
except Exception as e: | |
logging.error("Exception in keep_alive_function: {}".format(e)) | |
return 0 | |
def handler(event, context): | |
try: | |
functions = config.get("functions", []) | |
logging.debug("Functions {}".format(functions)) | |
if len(functions) == 0: | |
logging.info("Skipping, no functions") | |
return "OK" | |
with closing(ThreadPool(len(functions))) as pool: | |
mp = pool.map_async(keep_alive_function, functions) | |
_ = mp.get(300) | |
pool.terminate() | |
return "OK" | |
except Exception as e: | |
log.error("Exception in handler: {}".format(e)) | |
return "Internal Server Error" | |
if __name__ == "__main__": | |
handler(None, None) |
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{ | |
"region" : "eu-west-1", | |
"functions": [ | |
{ | |
"name": "YourLambdaFunctionName", | |
"containers": 1, | |
"event": { | |
"resource":"/frank/{proxy+}", | |
"headers": { | |
"Accept": "application/json" | |
}, | |
"httpMethod": "GET", | |
"requestContext": { | |
"stage": "v1" | |
}, | |
"path": "/v1/frank/" | |
} | |
} | |
] | |
} |
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