Lambda Monitoring

Lambda log monitoring and streaming to external services.

What it does

• Parsing and analysis of AWS Lambda CloudWatch Logs
• Sets Lambda CloudWatch log retention to 30 days to reduce storage cost
• Pipes AWS Lambda Logs to external logging services (i.e. Loggly, Logz or Datadog)
• Detects and sends AWS Lambda anomalies to external monitoring service (i.e. Rollbar)
• Fully transparent, no changes to existing Lambda functions required

Setup

1. Create New Github Project

• Install dev dependencies with yarn add -DE js-gardener @blackflux/robo-config-plugin eslint object-hash and
• Dependencies with yarn add -E lambda-monitor
• Add gardener.js containing

// eslint-disable-next-line import/no-extraneous-dependencies
const gardener = require('js-gardener');

if (require.main === module) {
  gardener().catch(() => process.exit(1));
}

• Add .roboconfig.json containing (adjust as necessary!)

{
  "lambda-monitor": {
    "tasks": [
      "assorted/@default"
    ],
    "variables": {
      "enableCloudTrail": "FILL_IN",
      "awsRegion": "AWS_REGION"
    }
  },
  "@blackflux/robo-config-plugin": {
    "tasks": [
      "assorted/@sls-closedsource"
    ],
    "variables": {
      "repoKey": "ORG_NAME/REPO_NAME",
      "circleCiReadToken": "CIRCLE_CI_TOKEN",
      "projectName": "PROJECT_NAME",
      "owner": "GH_USER_NAME",
      "ownerName": "ORG_NAME",
      "mergeBot": "MERGE_BOT_NAME",
      "awsRegion": "AWS_REGION",
      "namespace": "com.sls.ORG_NAME"
    }
  }
}

• Run node gardener.js
• Then run yarn install && yarn u
• Then enter docker container with . manage.sh
• Then run yarn install && u && t
• Create .depunusedignore

@blackflux/robo-config-plugin
@blackflux/eslint-plugin-rules
object-hash

• Follow instructions of generated file HOWTO.md (and generated CONFDOCS.md)

Disable Logging for a Lambda Function

To exclude a lambda function from being monitored simply add the tag "MONITORED": "0". Note that you need to manually unsubscribe if process-log has already been subscribed to the CloudWatch stream.

How it works

While deploying this project is straight forward, there is a lot of complexity going on behind the scenes to ensure:

• All Lambda functions are subscribed on initial deploy
• Newly created Lambda function are immediately subscribed
• Periodic checks for Lambda functions not subscribed (self healing)

There are four lambda function created per stage. All operations are only performed on lambda functions tagged with the corresponding stage.

process-logs - This lambda function is subscribed to CloudWatch and processes the logs. Anomalies are submitted to rollbar and all detected log events are sent to the configured logging services. Tagged with "MONITOR": "1" and "MONITORED": "0".

subscribe - Subscribes the process-logs lambda function (detected using the MONITOR tag) to all relevant CloudWatch Groups, excluding those functions that have the MONITORED tag set to 0.

set-retention - Updates the retention for all relevant CloudWatch Groups.

empty-bucket - Empty CloudTrail bucket when stage is removed from AWS.