-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathlambda-cloudwatch-trigger-stack.yaml
195 lines (171 loc) · 8.91 KB
/
lambda-cloudwatch-trigger-stack.yaml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
AWSTemplateFormatVersion: '2010-09-09'
Parameters:
LogGroupArns:
Description: "Comma-separated list of CloudWatch Log Group ARNs to trigger the Lambda function."
Type: CommaDelimitedList
LogGroupConfig:
Description: "JSON array of objects representing your LogGroup and Filters (if applicable). For example: [{\"LogGroupName\":\"logGroup1\",\"FilterPattern\":\"filter1\"}]"
Type: String
InvalidLogGroups:
Description: "Comma-separated list of CloudWatch Log Groups provided in use input which are invalid and should be skipped."
Type: CommaDelimitedList
LambdaFunctionArn:
Type: String
Description: Lambda arn to add event trigger
Conditions:
HasValidLogGroups: !Not [!Equals [!Select [0, !Ref LogGroupArns], ""]]
Resources:
NewRelicLogsCloudWatchLambdaLogGroupTriggers:
Type: 'Custom::CloudWatchNotifications'
Condition: HasValidLogGroups
Properties:
ServiceToken: !GetAtt NewRelicLogsCloudWatchLambda.Arn
LambdaFunctionArn: !Ref LambdaFunctionArn
LogGroupConfig: !Ref LogGroupConfig
InvalidLogGroups: !Ref InvalidLogGroups
NewRelicLogsCloudWatchLambdaIAMRole:
Type: "AWS::IAM::Role"
Condition: HasValidLogGroups
Properties:
AssumeRolePolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
Action:
- "sts:AssumeRole"
Policies:
- PolicyName: "LambdaExecutionPolicy"
PolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Action:
- logs:CreateLogGroup
- logs:CreateLogStream
- logs:PutLogEvents
- logs:DescribeLogGroups
- logs:DescribeLogStreams
- logs:PutSubscriptionFilter
- logs:DeleteSubscriptionFilter
- lambda:AddPermission
Resource: !Ref LogGroupArns
- Effect: Allow
Action:
- 'lambda:AddPermission'
Resource: !Ref LambdaFunctionArn
- Effect: Allow
Action:
- 'logs:CreateLogGroup'
- 'logs:CreateLogStream'
- 'logs:PutLogEvents'
Resource: 'arn:aws:logs:*:*:*'
NewRelicLogsCloudWatchLambda:
Type: 'AWS::Lambda::Function'
Condition: HasValidLogGroups
Properties:
Code:
ZipFile: |
import json
import boto3
import cfnresponse
import logging
import hashlib
import time
logger = logging.getLogger()
logger.setLevel(logging.INFO)
lambda_client = boto3.client('lambda')
log_client = boto3.client('logs')
def lambda_handler(event, context):
response = {}
try:
request_type = event['RequestType']
event_data = event['ResourceProperties']
lambda_arn = event_data.get('LambdaFunctionArn', '')
invalid_log_groups = set(event_data.get('InvalidLogGroups', []))
log_group_config_str = event_data.get('LogGroupConfig', [])
region = lambda_arn.split(':')[3]
account_id = lambda_arn.split(':')[4]
# Parsing LogGroupConfig JSON array
log_group_config = json.loads(log_group_config_str)
if request_type in ['Create', 'Update']:
for log_group in log_group_config:
log_group_name = log_group['LogGroupName']
if log_group_name in invalid_log_groups:
logger.info(f'Log group {log_group_name} is invalid. Skipping...')
continue
filter_pattern = log_group['FilterPattern'] if 'FilterPattern' in log_group else ''
# Log group ARN format: arn:aws:logs:region:account-id:log-group:log-group-name
# Example: arn:aws:logs:us-east-2:1234567890:log-group:Test:*
log_group_arn = f'arn:aws:logs:{region}:{account_id}:log-group:{log_group_name}:*'
add_permission_if_needed(event,context,lambda_arn, log_group_arn, log_group_name)
# Unique filter name for this stack using Lambda ARN
filter_name = f'NewRelicLogsLambdaSubscription_{hashlib.sha256(lambda_arn.encode()).hexdigest()[:20]}'
# Retry logic for PutSubscriptionFilter
max_retries = 5
initial_backoff_time_in_seconds = 1
backoff_multiplier = 2
backoff_time_in_seconds = initial_backoff_time_in_seconds
for attempt in range(max_retries):
try:
response = log_client.put_subscription_filter(
logGroupName=log_group_name,
filterName=filter_name,
filterPattern=filter_pattern,
destinationArn=lambda_arn
)
break
except log_client.exceptions.InvalidParameterException as e:
logger.info(f'Attempt {attempt + 1} to put subscription filter failed: {str(e)}')
if attempt < max_retries - 1:
logger.info(f'Retrying in {backoff_time_in_seconds} seconds...')
time.sleep(backoff_time_in_seconds)
backoff_time_in_seconds *= backoff_multiplier
else:
cfnresponse.send(event, context, cfnresponse.FAILED, {}, reason=f'{str(e)} - logGroupName: {logGroupName}')
elif request_type == 'Delete':
try:
for log_group in log_group_config:
log_group_name = log_group['LogGroupName']
if log_group_name in invalid_log_groups:
logger.info(f'Log group {log_group_name} is invalid. Skipping...')
continue
# Unique filter name for this stack using Lambda ARN
filter_name = f'NewRelicLogsLambdaSubscription_{hashlib.sha256(lambda_arn.encode()).hexdigest()[:20]}'
#remove the subscription filter
log_client.delete_subscription_filter(
logGroupName=log_group_name,
filterName=filter_name
)
except Exception as e:
logger.error(f'Delete failed for the log group subscription filters with error: {str(e)}')
cfnresponse.send(event, context, cfnresponse.SUCCESS, response)
cfnresponse.send(event, context, cfnresponse.SUCCESS, response)
except Exception as e:
logger.error(f'Error: {str(e)}')
cfnresponse.send(event, context, cfnresponse.FAILED, {}, reason=f'{str(e)}')
def add_permission_if_needed(event, context,lambda_arn, log_group_arn, log_group_name):
try:
# Create a hash of the log group name to ensure uniqueness and shorten it
hash_object = hashlib.sha256(log_group_name.encode())
short_log_group_name = hash_object.hexdigest()[:12] # Use the first 12 characters of the hash
statement_id = f"AllowCWLogs_{short_log_group_name}"
lambda_client.add_permission(
Action="lambda:InvokeFunction",
FunctionName=lambda_arn,
Principal="logs.amazonaws.com",
SourceArn=f"{log_group_arn}",
StatementId=statement_id
)
except lambda_client.exceptions.ResourceConflictException:
logger.info(f'Permission already exists for {log_group_arn}')
pass
except Exception as e:
logger.error(f'Error: {str(e)}')
cfnresponse.send(event, context, cfnresponse.FAILED, {}, reason=f'{str(e)}')
Handler: index.lambda_handler
Role: !GetAtt NewRelicLogsCloudWatchLambdaIAMRole.Arn
Runtime: python3.12
Timeout: 120