Creating and managing Amazon EBS volumes

#!/bin/bash

# Script to create and manage Amazon EBS volumes
# This script demonstrates how to create an EBS volume and attach it to an EC2 instance
# It can also create a test EC2 instance if needed

# Set up logging
LOG_FILE="ebs-volume-creation.log"
exec > >(tee -a "$LOG_FILE") 2>&1

echo "Starting EBS volume creation script at $(date)"
echo "=============================================="

# Function to handle errors
handle_error() {
    echo "ERROR: $1"
    echo "Resources created:"
    if [ -n "$VOLUME_ID" ]; then
        echo "- EBS Volume: $VOLUME_ID"
    fi
    if [ -n "$INSTANCE_ID" ]; then
        echo "- EC2 Instance: $INSTANCE_ID"
    fi
    if [ -n "$SG_ID" ]; then
        echo "- Security Group: $SG_ID"
    fi
    
    echo ""
    echo "==========================================="
    echo "CLEANUP CONFIRMATION"
    echo "==========================================="
    echo "An error occurred. Do you want to clean up created resources? (y/n): "
    read -r CLEANUP_CHOICE
    
    if [[ "$CLEANUP_CHOICE" =~ ^[Yy]$ ]]; then
        cleanup_resources
    else
        echo "Resources were not cleaned up. You will need to delete them manually."
    fi
    
    exit 1
}

# Function to clean up resources
cleanup_resources() {
    echo "Cleaning up resources..."
    
    if [ -n "$VOLUME_ID" ] && [ "$ATTACHED" = true ]; then
        echo "Detaching volume $VOLUME_ID..."
        aws ec2 detach-volume --volume-id "$VOLUME_ID"
        
        # Wait for volume to be detached
        echo "Waiting for volume to be detached..."
        aws ec2 wait volume-available --volume-ids "$VOLUME_ID"
    fi
    
    if [ -n "$VOLUME_ID" ]; then
        echo "Deleting volume $VOLUME_ID..."
        aws ec2 delete-volume --volume-id "$VOLUME_ID"
    fi
    
    if [ -n "$INSTANCE_ID" ] && [ "$CREATED_INSTANCE" = true ]; then
        echo "Terminating instance $INSTANCE_ID..."
        aws ec2 terminate-instances --instance-ids "$INSTANCE_ID"
        echo "Waiting for instance to terminate..."
        aws ec2 wait instance-terminated --instance-ids "$INSTANCE_ID"
    fi
    
    # Clean up security group if created
    if [ -n "$SG_ID" ] && [ "$CREATED_INSTANCE" = true ]; then
        echo "Deleting security group $SG_ID..."
        # Wait a bit for instance termination to complete
        sleep 10
        aws ec2 delete-security-group --group-id "$SG_ID" 2>/dev/null || echo "Security group may have dependencies, delete manually if needed"
    fi
    
    echo "Cleanup completed."
}

# Function to get available instance type
get_available_instance_type() {
    local region=$1
    
    # Try instance types in order of preference (cheapest first)
    local instance_types=("t3.nano" "t3.micro" "t2.micro" "t2.nano")
    
    for instance_type in "${instance_types[@]}"; do
        local available=$(aws ec2 describe-instance-type-offerings \
            --region "$region" \
            --filters "Name=instance-type,Values=$instance_type" \
            --query "length(InstanceTypeOfferings)" \
            --output text)
        
        if [ "$available" -gt 0 ]; then
            echo "$instance_type"
            return 0
        fi
    done
    
    # If none of the preferred types are available, get any available type
    local fallback_type=$(aws ec2 describe-instance-type-offerings \
        --region "$region" \
        --query "InstanceTypeOfferings[0].InstanceType" \
        --output text)
    
    if [ "$fallback_type" != "None" ] && [ -n "$fallback_type" ]; then
        echo "$fallback_type"
        return 0
    fi
    
    return 1
}

# Get current region
REGION=$(aws configure get region)
if [ -z "$REGION" ]; then
    REGION=$(aws ec2 describe-availability-zones --query "AvailabilityZones[0].RegionName" --output text)
fi

echo "Using region: $REGION"

# Get available Availability Zones
echo "Retrieving available Availability Zones..."
AZ=$(aws ec2 describe-availability-zones --filters "Name=state,Values=available" --query "AvailabilityZones[0].ZoneName" --output text)
if [ -z "$AZ" ]; then
    handle_error "Failed to retrieve Availability Zones"
fi
echo "Using Availability Zone: $AZ"

# Create a gp3 volume
echo "Creating a 10 GiB gp3 volume in $AZ..."
VOLUME_ID=$(aws ec2 create-volume \
    --volume-type gp3 \
    --size 10 \
    --availability-zone "$AZ" \
    --tag-specifications 'ResourceType=volume,Tags=[{Key=Name,Value=EBSTutorialVolume},{Key=Purpose,Value=Tutorial}]' \
    --query 'VolumeId' \
    --output text)

if [ -z "$VOLUME_ID" ]; then
    handle_error "Failed to create EBS volume"
fi

echo "Volume created with ID: $VOLUME_ID"

# Wait for volume to become available
echo "Waiting for volume to become available..."
aws ec2 wait volume-available --volume-ids "$VOLUME_ID"
if [ $? -ne 0 ]; then
    handle_error "Volume did not become available"
fi

# Check volume details
echo "Retrieving volume details..."
aws ec2 describe-volumes --volume-ids "$VOLUME_ID"

# Ask if user wants to attach the volume to an instance
echo ""
echo "==========================================="
echo "VOLUME ATTACHMENT"
echo "==========================================="
echo "Do you want to attach this volume to an EC2 instance? (y/n): "
read -r ATTACH_CHOICE

ATTACHED=false
CREATED_INSTANCE=false
INSTANCE_ID=""
SG_ID=""

if [[ "$ATTACH_CHOICE" =~ ^[Yy]$ ]]; then
    # List available instances in the same AZ
    echo "Retrieving EC2 instances in $AZ..."
    INSTANCES_COUNT=$(aws ec2 describe-instances \
        --filters "Name=availability-zone,Values=$AZ" "Name=instance-state-name,Values=running" \
        --query "length(Reservations[].Instances[])" \
        --output text)
    
    # Check if there are any running instances in the AZ
    if [ "$INSTANCES_COUNT" -eq 0 ]; then
        echo "No running instances found in $AZ."
        echo ""
        echo "Would you like to create a test EC2 instance? (y/n): "
        read -r CREATE_INSTANCE_CHOICE
        
        if [[ "$CREATE_INSTANCE_CHOICE" =~ ^[Yy]$ ]]; then
            # Get available instance type
            echo "Finding available instance type for region $REGION..."
            INSTANCE_TYPE=$(get_available_instance_type "$REGION")
            if [ $? -ne 0 ] || [ -z "$INSTANCE_TYPE" ]; then
                handle_error "No suitable instance type found in region $REGION"
            fi
            echo "Using instance type: $INSTANCE_TYPE"
            
            # Get the latest Amazon Linux 2 AMI
            echo "Finding the latest Amazon Linux 2 AMI..."
            AMI_ID=$(aws ec2 describe-images \
                --owners amazon \
                --filters "Name=name,Values=amzn2-ami-hvm-*-x86_64-gp2" "Name=state,Values=available" \
                --query "sort_by(Images, &CreationDate)[-1].ImageId" \
                --output text)
            
            if [ -z "$AMI_ID" ]; then
                handle_error "Failed to find a suitable AMI"
            fi
            
            echo "Using AMI: $AMI_ID"
            
            # Check if a default VPC exists
            DEFAULT_VPC_ID=$(aws ec2 describe-vpcs \
                --filters "Name=isDefault,Values=true" \
                --query "Vpcs[0].VpcId" \
                --output text)
            
            if [ "$DEFAULT_VPC_ID" = "None" ] || [ -z "$DEFAULT_VPC_ID" ]; then
                handle_error "No default VPC found. Please create a VPC and subnet before running this script."
            fi
            
            # Get a subnet in the selected AZ
            SUBNET_ID=$(aws ec2 describe-subnets \
                --filters "Name=vpc-id,Values=$DEFAULT_VPC_ID" "Name=availability-zone,Values=$AZ" \
                --query "Subnets[0].SubnetId" \
                --output text)
            
            if [ -z "$SUBNET_ID" ] || [ "$SUBNET_ID" = "None" ]; then
                handle_error "No subnet found in $AZ. Please create a subnet before running this script."
            fi
            
            echo "Using subnet: $SUBNET_ID"
            
            # Create a security group that allows SSH
            SG_NAME="EBSTutorialSG-$(date +%s)"
            SG_ID=$(aws ec2 create-security-group \
                --group-name "$SG_NAME" \
                --description "Security group for EBS tutorial" \
                --vpc-id "$DEFAULT_VPC_ID" \
                --query "GroupId" \
                --output text)
            
            if [ -z "$SG_ID" ]; then
                handle_error "Failed to create security group"
            fi
            
            echo "Created security group: $SG_ID"
            
            # Add a rule to allow SSH
            aws ec2 authorize-security-group-ingress \
                --group-id "$SG_ID" \
                --protocol tcp \
                --port 22 \
                --cidr 0.0.0.0/0
            
            echo "Added SSH rule to security group"
            
            # Create the instance
            echo "Creating EC2 instance in $AZ with instance type $INSTANCE_TYPE..."
            INSTANCE_ID=$(aws ec2 run-instances \
                --image-id "$AMI_ID" \
                --instance-type "$INSTANCE_TYPE" \
                --subnet-id "$SUBNET_ID" \
                --security-group-ids "$SG_ID" \
                --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=EBSTutorialInstance},{Key=Purpose,Value=Tutorial}]' \
                --query "Instances[0].InstanceId" \
                --output text)
            
            if [ -z "$INSTANCE_ID" ]; then
                handle_error "Failed to create EC2 instance"
            fi
            
            CREATED_INSTANCE=true
            echo "Instance created with ID: $INSTANCE_ID"
            
            # Wait for the instance to be running
            echo "Waiting for instance to be running..."
            aws ec2 wait instance-running --instance-ids "$INSTANCE_ID"
            
            # Wait a bit more for the instance to initialize
            echo "Waiting for instance initialization (30 seconds)..."
            sleep 30
        else
            echo "Skipping instance creation and volume attachment."
            INSTANCE_ID=""
        fi
    else
        # Display available instances
        echo "Available instances in $AZ:"
        aws ec2 describe-instances \
            --filters "Name=availability-zone,Values=$AZ" "Name=instance-state-name,Values=running" \
            --query "Reservations[*].Instances[*].[InstanceId,Tags[?Key=='Name'].Value|[0],InstanceType]" \
            --output table
        
        # Ask for instance ID
        echo ""
        echo "Enter the instance ID to attach the volume to (or press Enter to skip): "
        read -r INSTANCE_ID
    fi
    
    if [ -n "$INSTANCE_ID" ]; then
        # Attach volume to the instance
        echo "Attaching volume $VOLUME_ID to instance $INSTANCE_ID..."
        ATTACH_RESULT=$(aws ec2 attach-volume \
            --volume-id "$VOLUME_ID" \
            --instance-id "$INSTANCE_ID" \
            --device "/dev/sdf" \
            --query 'State' \
            --output text)
        
        if [ $? -ne 0 ] || [ -z "$ATTACH_RESULT" ]; then
            handle_error "Failed to attach volume to instance"
        fi
        
        ATTACHED=true
        echo "Volume attached successfully. Device: /dev/sdf"
        
        # Verify attachment
        echo "Verifying attachment..."
        aws ec2 describe-volumes \
            --volume-ids "$VOLUME_ID" \
            --query "Volumes[0].Attachments"
    else
        echo "Skipping volume attachment."
    fi
else
    echo "Skipping volume attachment."
fi

# Display summary of created resources
echo ""
echo "==========================================="
echo "RESOURCE SUMMARY"
echo "==========================================="
echo "Created resources:"
echo "- EBS Volume: $VOLUME_ID"
if [ "$ATTACHED" = true ]; then
    echo "  - Attached to: $INSTANCE_ID as /dev/sdf"
fi
if [ "$CREATED_INSTANCE" = true ]; then
    echo "- EC2 Instance: $INSTANCE_ID (type: $INSTANCE_TYPE)"
fi
if [ -n "$SG_ID" ]; then
    echo "- Security Group: $SG_ID"
fi

# Ask if user wants to clean up resources
echo ""
echo "==========================================="
echo "CLEANUP CONFIRMATION"
echo "==========================================="
echo "Do you want to clean up all created resources? (y/n): "
read -r CLEANUP_CHOICE

if [[ "$CLEANUP_CHOICE" =~ ^[Yy]$ ]]; then
    cleanup_resources
else
    echo ""
    echo "Resources were not cleaned up. You can manually delete them later."
    if [ -n "$VOLUME_ID" ]; then
        if [ "$ATTACHED" = true ]; then
            echo "To detach the volume:"
            echo "  aws ec2 detach-volume --volume-id $VOLUME_ID"
        fi
        echo "To delete the volume:"
        echo "  aws ec2 delete-volume --volume-id $VOLUME_ID"
    fi
    if [ "$CREATED_INSTANCE" = true ]; then
        echo "To terminate the instance:"
        echo "  aws ec2 terminate-instances --instance-ids $INSTANCE_ID"
    fi
    if [ -n "$SG_ID" ]; then
        echo "To delete the security group (after instance termination):"
        echo "  aws ec2 delete-security-group --group-id $SG_ID"
    fi
fi

echo ""
echo "Script completed at $(date)"
echo "=============================================="