From e9656f732822bbf871dc61d3457040c2391760cf Mon Sep 17 00:00:00 2001
From: simlu <simlu@users.noreply.github.com>
Date: Fri, 25 Jul 2025 11:45:31 -0700
Subject: [PATCH] fix: now filtering cloudwatch logs

---
 src/logic/subscribe.js                                      | 6 +++++-
 src/logic/util/lambda.js                                    | 5 +++--
 src/vars.js                                                 | 1 +
 .../subscribe/skipByTag.spec.json_recording.json            | 2 +-
 .../subscribe/subscribe.spec.json_recording.json            | 2 +-
 ...a_testingSubscribeCloudWatchLogGroupError_recording.json | 2 +-
 6 files changed, 12 insertions(+), 6 deletions(-)
 create mode 100644 src/vars.js

diff --git a/src/logic/subscribe.js b/src/logic/subscribe.js
index 4b3f72f4..26b642a7 100644
--- a/src/logic/subscribe.js
+++ b/src/logic/subscribe.js
@@ -1,6 +1,7 @@
 import get from 'lodash.get';
 import { logger } from 'lambda-monitor-logger';
 import Lambda from './util/lambda.js';
+import { filterPattern } from '../vars.js';
 
 const lambda = Lambda();
 
@@ -16,7 +17,10 @@ export default () => lambda
     const monitor = functions.find((f) => get(f, 'Tags.MONITOR', null) === '1');
     const monitored = functions
       .filter((f) => get(f, 'Tags.MONITORED', null) !== '0')
-      .filter((f) => f.subscriptionFilters.every((e) => e.destinationArn !== monitor.FunctionARN));
+      .filter((f) => f.subscriptionFilters.every((e) => (
+        e.destinationArn !== monitor.FunctionARN
+        || e.filterPattern !== filterPattern
+      )));
     return Promise.all(monitored.map((producer) => lambda.subscribeCloudWatchLogGroup(monitor, producer)));
   }).catch((e) => {
     if (e.name === 'ThrottlingException') {
diff --git a/src/logic/util/lambda.js b/src/logic/util/lambda.js
index b66fb7ba..13b3d99e 100644
--- a/src/logic/util/lambda.js
+++ b/src/logic/util/lambda.js
@@ -1,5 +1,6 @@
 import get from 'lodash.get';
 import aws from './aws.js';
+import { filterPattern } from '../../vars.js';
 
 export default () => {
   const logGroupName = (fn) => `/aws/lambda/${fn.FunctionName}`;
@@ -43,8 +44,8 @@ export default () => {
   const subscribeCloudWatchLogGroup = (monitor, producer) => aws
     .call('CloudWatchLogs:PutSubscriptionFilterCommand', {
       destinationArn: monitor.FunctionARN,
-      filterName: 'NoneFilter',
-      filterPattern: '',
+      filterName: 'NoneFilter', // existing name, can't really change
+      filterPattern,
       logGroupName: logGroupName(producer)
     });
 
diff --git a/src/vars.js b/src/vars.js
new file mode 100644
index 00000000..ec16be87
--- /dev/null
+++ b/src/vars.js
@@ -0,0 +1 @@
+export const filterPattern = '-%^START RequestId: |^END RequestId: %';
diff --git a/test/lambda/__cassettes/subscribe/skipByTag.spec.json_recording.json b/test/lambda/__cassettes/subscribe/skipByTag.spec.json_recording.json
index 5d38b764..ef6f7fc2 100644
--- a/test/lambda/__cassettes/subscribe/skipByTag.spec.json_recording.json
+++ b/test/lambda/__cassettes/subscribe/skipByTag.spec.json_recording.json
@@ -77,7 +77,7 @@
           "destinationArn": "arn:aws:lambda:us-east-1:1234567890:function:lambda-function-one",
           "distribution": "ByLogStream",
           "filterName": "NoneFilter",
-          "filterPattern": "",
+          "filterPattern": "-%^START RequestId: |^END RequestId: %",
           "logGroupName": "/aws/lambda/lambda-function-two"
         }
       ]
diff --git a/test/lambda/__cassettes/subscribe/subscribe.spec.json_recording.json b/test/lambda/__cassettes/subscribe/subscribe.spec.json_recording.json
index b2aece47..dcd3c6c4 100644
--- a/test/lambda/__cassettes/subscribe/subscribe.spec.json_recording.json
+++ b/test/lambda/__cassettes/subscribe/subscribe.spec.json_recording.json
@@ -81,7 +81,7 @@
     "body": {
       "destinationArn": "arn:aws:lambda:us-east-1:1234567890:function:lambda-function-one",
       "filterName": "NoneFilter",
-      "filterPattern": "",
+      "filterPattern": "-%^START RequestId: |^END RequestId: %",
       "logGroupName": "/aws/lambda/lambda-function-two"
     },
     "status": 200,
diff --git a/test/logic/util/lambda.spec.js__cassettes/testingLambda_testingSubscribeCloudWatchLogGroupError_recording.json b/test/logic/util/lambda.spec.js__cassettes/testingLambda_testingSubscribeCloudWatchLogGroupError_recording.json
index f569c905..37d1b44a 100644
--- a/test/logic/util/lambda.spec.js__cassettes/testingLambda_testingSubscribeCloudWatchLogGroupError_recording.json
+++ b/test/logic/util/lambda.spec.js__cassettes/testingLambda_testingSubscribeCloudWatchLogGroupError_recording.json
@@ -6,7 +6,7 @@
     "body": {
       "destinationArn": "FUNCTION_ARN",
       "filterName": "NoneFilter",
-      "filterPattern": "",
+      "filterPattern": "-%^START RequestId: |^END RequestId: %",
       "logGroupName": "/aws/lambda/FUNCTION_NAME"
     },
     "status": 400,