Get started with Amazon S3 using the CLI

#!/bin/bash

# Amazon S3 Getting Started Tutorial Script
# This script demonstrates basic S3 operations including:
# - Creating a bucket
# - Configuring bucket settings
# - Uploading, downloading, and copying objects
# - Deleting objects and buckets

# Latest fixes:
# 1. Fixed folder creation using temporary file
# 2. Corrected versioned object deletion in cleanup
# 3. Improved error handling for cleanup operations

# Set up error handling
set -e
trap 'cleanup_handler $?' EXIT

# Log file setup
LOG_FILE="s3-tutorial-$(date +%Y%m%d-%H%M%S).log"
exec > >(tee -a "$LOG_FILE") 2>&1

# Function to log messages
log() {
    echo "[$(date +"%Y-%m-%d %H:%M:%S")] $1"
}

# Function to handle errors
handle_error() {
    log "ERROR: $1"
    exit 1
}

# Function to check if a bucket exists
bucket_exists() {
    if aws s3api head-bucket --bucket "$1" 2>/dev/null; then
        return 0
    else
        return 1
    fi
}

# Function to delete all versions of objects in a bucket
delete_all_versions() {
    local bucket=$1
    log "Deleting all object versions from bucket $bucket..."
    
    # Get and delete all versions
    versions=$(aws s3api list-object-versions --bucket "$bucket" --query 'Versions[].{Key:Key,VersionId:VersionId}' --output json 2>/dev/null)
    if [ -n "$versions" ] && [ "$versions" != "null" ]; then
        echo "{\"Objects\": $versions}" | aws s3api delete-objects --bucket "$bucket" --delete file:///dev/stdin >/dev/null 2>&1 || log "Warning: Some versions could not be deleted"
    fi
    
    # Get and delete all delete markers
    markers=$(aws s3api list-object-versions --bucket "$bucket" --query 'DeleteMarkers[].{Key:Key,VersionId:VersionId}' --output json 2>/dev/null)
    if [ -n "$markers" ] && [ "$markers" != "null" ]; then
        echo "{\"Objects\": $markers}" | aws s3api delete-objects --bucket "$bucket" --delete file:///dev/stdin >/dev/null 2>&1 || log "Warning: Some delete markers could not be deleted"
    fi
}

# Function to handle cleanup on exit
cleanup_handler() {
    local exit_code=$1
    
    # Only run cleanup if it hasn't been run already
    if [ -z "$CLEANUP_DONE" ]; then
        cleanup
    fi
    
    exit $exit_code
}

# Function to clean up resources
cleanup() {
    log "Starting cleanup process..."
    CLEANUP_DONE=1
    
    # List all resources created for confirmation
    log "Resources created:"
    if [ -n "$BUCKET_NAME" ]; then
        log "- S3 Bucket: $BUCKET_NAME"
        
        # Only try to list objects if the bucket exists
        if bucket_exists "$BUCKET_NAME"; then
            # Check if any objects were created
            OBJECTS=$(aws s3api list-objects-v2 --bucket "$BUCKET_NAME" --query 'Contents[].Key' --output text 2>/dev/null || echo "")
            if [ -n "$OBJECTS" ]; then
                log "- Objects in bucket:"
                echo "$OBJECTS" | tr '\t' '\n' | while read -r obj; do
                    log "  - $obj"
                done
            fi
            
            # Ask for confirmation before cleanup
            read -p "Do you want to proceed with cleanup and delete all resources? (y/n): " confirm
            if [[ $confirm != [yY] && $confirm != [yY][eE][sS] ]]; then
                log "Cleanup aborted by user."
                return
            fi
            
            # Delete all versions of objects
            delete_all_versions "$BUCKET_NAME"
            
            # Delete the bucket
            log "Deleting bucket $BUCKET_NAME..."
            aws s3api delete-bucket --bucket "$BUCKET_NAME" || log "Warning: Failed to delete bucket"
        else
            log "Bucket $BUCKET_NAME does not exist, skipping cleanup"
        fi
    fi
    
    # Clean up local files
    log "Removing local files..."
    rm -f sample-file.txt sample-document.txt downloaded-sample-file.txt empty-file.tmp
    
    log "Cleanup completed."
}

# Generate a random bucket name
generate_bucket_name() {
    local hex_id
    hex_id=$(openssl rand -hex 6)
    echo "demo-s3-bucket-$hex_id"
}

# Main script execution
main() {
    log "Starting Amazon S3 Getting Started Tutorial"
    
    # Generate a unique bucket name
    BUCKET_NAME=$(generate_bucket_name)
    log "Generated bucket name: $BUCKET_NAME"
    
    # Step 1: Create a bucket
    log "Step 1: Creating S3 bucket..."
    
    # Get the current region or default to us-east-1
    REGION=$(aws configure get region)
    REGION=${REGION:-us-east-1}
    log "Using region: $REGION"
    
    if [ "$REGION" = "us-east-1" ]; then
        aws s3api create-bucket --bucket "$BUCKET_NAME" || handle_error "Failed to create bucket"
    else
        aws s3api create-bucket \
            --bucket "$BUCKET_NAME" \
            --region "$REGION" \
            --create-bucket-configuration LocationConstraint="$REGION" || handle_error "Failed to create bucket"
    fi
    log "Bucket created successfully"
    
    # Configure bucket settings
    log "Configuring bucket settings..."
    
    # Block public access (security best practice)
    log "Blocking public access..."
    aws s3api put-public-access-block \
        --bucket "$BUCKET_NAME" \
        --public-access-block-configuration "BlockPublicAcls=true,IgnorePublicAcls=true,BlockPublicPolicy=true,RestrictPublicBuckets=true" || handle_error "Failed to configure public access block"
    
    # Enable versioning
    log "Enabling versioning..."
    aws s3api put-bucket-versioning \
        --bucket "$BUCKET_NAME" \
        --versioning-configuration Status=Enabled || handle_error "Failed to enable versioning"
    
    # Set default encryption
    log "Setting default encryption..."
    aws s3api put-bucket-encryption \
        --bucket "$BUCKET_NAME" \
        --server-side-encryption-configuration '{"Rules": [{"ApplyServerSideEncryptionByDefault": {"SSEAlgorithm": "AES256"}}]}' || handle_error "Failed to set encryption"
    
    # Step 2: Upload an object
    log "Step 2: Uploading objects to bucket..."
    
    # Create a sample file
    echo "This is a sample file for the S3 tutorial." > sample-file.txt
    
    # Upload the file
    aws s3api put-object \
        --bucket "$BUCKET_NAME" \
        --key "sample-file.txt" \
        --body "sample-file.txt" || handle_error "Failed to upload object"
    log "Object uploaded successfully"
    
    # Upload with metadata
    echo "This is a document with metadata." > sample-document.txt
    aws s3api put-object \
        --bucket "$BUCKET_NAME" \
        --key "documents/sample-document.txt" \
        --body "sample-document.txt" \
        --content-type "text/plain" \
        --metadata "author=AWSDocumentation,purpose=tutorial" || handle_error "Failed to upload object with metadata"
    log "Object with metadata uploaded successfully"
    
    # Step 3: Download an object
    log "Step 3: Downloading object from bucket..."
    aws s3api get-object \
        --bucket "$BUCKET_NAME" \
        --key "sample-file.txt" \
        "downloaded-sample-file.txt" || handle_error "Failed to download object"
    log "Object downloaded successfully"
    
    # Check if an object exists
    log "Checking if object exists..."
    aws s3api head-object \
        --bucket "$BUCKET_NAME" \
        --key "sample-file.txt" || handle_error "Object does not exist"
    log "Object exists"
    
    # Step 4: Copy object to a folder
    log "Step 4: Copying object to a folder..."
    
    # Create a folder structure using a temporary empty file
    log "Creating folder structure..."
    touch empty-file.tmp
    aws s3api put-object \
        --bucket "$BUCKET_NAME" \
        --key "favorite-files/" \
        --body empty-file.tmp || handle_error "Failed to create folder"
    
    # Copy the object
    log "Copying object..."
    aws s3api copy-object \
        --bucket "$BUCKET_NAME" \
        --copy-source "$BUCKET_NAME/sample-file.txt" \
        --key "favorite-files/sample-file.txt" || handle_error "Failed to copy object"
    log "Object copied successfully"
    
    # List objects in the bucket
    log "Listing all objects in the bucket..."
    aws s3api list-objects-v2 \
        --bucket "$BUCKET_NAME" \
        --query 'Contents[].Key' \
        --output table || handle_error "Failed to list objects"
    
    # List objects with a specific prefix
    log "Listing objects in the favorite-files folder..."
    aws s3api list-objects-v2 \
        --bucket "$BUCKET_NAME" \
        --prefix "favorite-files/" \
        --query 'Contents[].Key' \
        --output table || handle_error "Failed to list objects with prefix"
    
    # Add tags to the bucket
    log "Adding tags to the bucket..."
    aws s3api put-bucket-tagging \
        --bucket "$BUCKET_NAME" \
        --tagging 'TagSet=[{Key=Project,Value=S3Tutorial},{Key=Environment,Value=Demo}]' || handle_error "Failed to add tags"
    log "Tags added successfully"
    
    log "Tutorial completed successfully!"
}

# Execute the main function
main