CloudWatch Logger + Sentry

Production-ready Express app with centralized logging to AWS CloudWatch and error tracking with Sentry.

Features

• ✅ Environment-aware logging (dev vs production)
• ✅ Structured JSON logs in CloudWatch
• ✅ Automatic request tracing with unique IDs
• ✅ IAM role-based authentication (no hardcoded keys)
• ✅ Daily log stream rotation
• ✅ Request performance tracking
• ✅ Sentry error tracking and monitoring

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Quick Start (Local Development)

npm install
npm start

This runs in development mode with console-only logging.

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Production Deployment on EC2

Step 1: Create CloudWatch Log Group

1. Go to AWS CloudWatch Console → Logs → Log groups
2. Click Create log group
3. Name: my-app-logs (or your preferred name)
4. Click Create

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Step 2: Create IAM Role with CloudWatch Permissions

Option A: Using AWS Managed Policy (Easiest)

1. Go to IAM Console → Roles → Create role
2. Trusted entity type: AWS service
3. Use case: EC2
4. Click Next
5. Add permissions: Search and select CloudWatchAgentServerPolicy
6. Click Next
7. Role name: EC2-CloudWatch-Role (or your preferred name)
8. Click Create role

Option B: Using Custom JSON Policy

1. Go to IAM Console → Policies → Create policy
2. Click JSON tab
3. Paste this policy:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "logs:CreateLogGroup",
        "logs:CreateLogStream",
        "logs:PutLogEvents",
        "logs:DescribeLogStreams"
      ],
      "Resource": "*"
    }
  ]
}

4. Click Next
5. Policy name: CloudWatchLogsAccess
6. Click Create policy
7. Go to Roles → Create role → EC2 → Attach your new policy → Name it → Create

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Step 3: Attach IAM Role to EC2 Instance

1. Go to EC2 Console → Instances
2. Select your instance
3. Actions → Security → Modify IAM role
4. Select the role created in Step 2 (EC2-CloudWatch-Role)
5. Click Update IAM role

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Step 4: Configure Environment Variables

SSH into your EC2 instance and create .env file:

cd /path/to/your/app
nano .env

Add these variables:

NODE_ENV=production
AWS_CLOUDWATCH_ENABLED=true
AWS_REGION=us-east-1
AWS_CLOUDWATCH_LOG_GROUP=my-app-logs
PORT=3000

Important:

• Replace us-east-1 with your AWS region
• Replace my-app-logs with your log group name
• Do NOT add AWS_ACCESS_KEY_ID or AWS_SECRET_ACCESS_KEY (use IAM role)

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Step 5: Install Dependencies and Start App

# Install dependencies
npm install

# Start the application
npm start

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Step 6: Test Logging

# Generate test logs
curl http://localhost:3000/
curl http://localhost:3000/test/info
curl http://localhost:3000/test/warn
curl http://localhost:3000/test/error
curl http://localhost:3000/test/all

# Test Sentry error tracking
curl http://localhost:3000/debug-sentry

Wait 30-60 seconds, then check CloudWatch Console. You should see:

• Log group: my-app-logs
• Log stream: app-YYYY-MM-DD (e.g., app-2025-10-16)
• JSON formatted logs with trace IDs

Sentry Setup

Add to .env:

SENTRY_DSN=your-sentry-dsn-here

Test: Visit /debug-sentry endpoint to trigger an error.

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License

MIT