aws-s3

AWS S3

Manage Amazon S3 object storage with production-grade security, lifecycle policies, replication, and access controls.

When to Use This Skill

• Creating S3 buckets with security hardening (encryption, public access block, versioning)
• Writing bucket policies to enforce HTTPS, restrict IP ranges, or grant cross-account access
• Setting up lifecycle rules to transition objects between storage classes
• Configuring cross-region replication for disaster recovery
• Generating presigned URLs for temporary access to private objects
• Setting up static website hosting or CloudFront origins
• Troubleshooting access denied errors or policy conflicts

Prerequisites

• AWS CLI v2 installed and configured
• IAM permissions: s3:*, s3-object-lambda:*, kms:* (for SSE-KMS)
• For replication: IAM role with replication permissions and destination bucket in target region
• For logging: a separate logging bucket with appropriate ACL

Create and Secure a Bucket

# Create a bucket (us-east-1 does not need LocationConstraint)
aws s3api create-bucket \
  --bucket my-app-data-prod \
  --region us-east-1

# Create a bucket in another region
aws s3api create-bucket \
  --bucket my-app-data-dr \
  --region us-west-2 \
  --create-bucket-configuration LocationConstraint=us-west-2

# Block ALL public access (always do this first)
aws s3api put-public-access-block \
  --bucket my-app-data-prod \
  --public-access-block-configuration '{
    "BlockPublicAcls": true,
    "IgnorePublicAcls": true,
    "BlockPublicPolicy": true,
    "RestrictPublicBuckets": true
  }'

# Enable versioning
aws s3api put-bucket-versioning \
  --bucket my-app-data-prod \
  --versioning-configuration Status=Enabled

# Enable server-side encryption with SSE-KMS
aws s3api put-bucket-encryption \
  --bucket my-app-data-prod \
  --server-side-encryption-configuration '{
    "Rules": [{
      "ApplyServerSideEncryptionByDefault": {
        "SSEAlgorithm": "aws:kms",
        "KMSMasterKeyID": "alias/s3-key"
      },
      "BucketKeyEnabled": true
    }]
  }'

# Enable access logging
aws s3api put-bucket-logging \
  --bucket my-app-data-prod \
  --bucket-logging-status '{
    "LoggingEnabled": {
      "TargetBucket": "my-access-logs-bucket",
      "TargetPrefix": "s3-logs/my-app-data-prod/"
    }
  }'

# Add tags
aws s3api put-bucket-tagging \
  --bucket my-app-data-prod \
  --tagging '{
    "TagSet": [
      {"Key": "Environment", "Value": "production"},
      {"Key": "Team", "Value": "platform"},
      {"Key": "DataClassification", "Value": "confidential"}
    ]
  }'