View a markdown version of this page

Creating your first CloudFormation stack - AWS SDK Code Examples

There are more AWS SDK examples available in the AWS Doc SDK Examples GitHub repo.

Creating your first CloudFormation stack

The following code example shows how to:

  • Create a CloudFormation template

  • Test the web server

  • Clean up resources

Bash
AWS CLI with Bash script
Note

There's more on GitHub. Find the complete example and learn how to set up and run in the Sample developer tutorials repository. 

#!/bin/bash

# CloudFormation Getting Started Script
# This script creates a CloudFormation stack with a web server and security group,
# monitors the stack creation, and provides cleanup options.

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

echo "==================================================="
echo "AWS CloudFormation Getting Started Tutorial"
echo "==================================================="
echo "This script will create a CloudFormation stack with:"
echo "- An EC2 instance running a simple web server"
echo "- A security group allowing HTTP access from your IP"
echo ""
echo "Starting at: $(date)"
echo ""

# Function to clean up resources
cleanup() {
    echo ""
    echo "==================================================="
    echo "CLEANING UP RESOURCES"
    echo "==================================================="
    
    if [ -n "$STACK_NAME" ]; then
        echo "Deleting CloudFormation stack: $STACK_NAME"
        aws cloudformation delete-stack --stack-name "$STACK_NAME"
        
        echo "Waiting for stack deletion to complete..."
        aws cloudformation wait stack-delete-complete --stack-name "$STACK_NAME"
        
        echo "Stack deletion complete."
    fi
    
    if [ -f "$TEMPLATE_FILE" ]; then
        echo "Removing local template file: $TEMPLATE_FILE"
        rm -f "$TEMPLATE_FILE"
    fi
    
    echo "Cleanup completed at: $(date)"
}

# Function to handle errors
handle_error() {
    echo ""
    echo "==================================================="
    echo "ERROR: $1"
    echo "==================================================="
    echo "Resources created before error:"
    if [ -n "$STACK_NAME" ]; then
        echo "- CloudFormation stack: $STACK_NAME"
    fi
    echo ""
    
    echo "Would you like to clean up these resources? (y/n): "
    read -r CLEANUP_CHOICE
    
    if [[ "$CLEANUP_CHOICE" =~ ^[Yy]$ ]]; then
        cleanup
    else
        echo "Resources were not cleaned up. You may need to delete them manually."
    fi
    
    exit 1
}

# Set up trap for script interruption
trap 'handle_error "Script interrupted"' INT TERM

# Generate a unique stack name
STACK_NAME="MyTestStack"
TEMPLATE_FILE="webserver-template.yaml"

# Step 1: Create the CloudFormation template file
echo "Creating CloudFormation template file: $TEMPLATE_FILE"
cat > "$TEMPLATE_FILE" << 'EOF'
AWSTemplateFormatVersion: 2010-09-09
Description: CloudFormation Template for WebServer with Security Group and EC2 Instance

Parameters:
  LatestAmiId:
    Description: The latest Amazon Linux 2 AMI from the Parameter Store
    Type: 'AWS::SSM::Parameter::Value<AWS::EC2::Image::Id>'
    Default: '/aws/service/ami-amazon-linux-latest/amzn2-ami-hvm-x86_64-gp2'

  InstanceType:
    Description: WebServer EC2 instance type
    Type: String
    Default: t2.micro
    AllowedValues:
      - t3.micro
      - t2.micro
    ConstraintDescription: must be a valid EC2 instance type.
    
  MyIP:
    Description: Your IP address in CIDR format (e.g. 203.0.113.1/32).
    Type: String
    MinLength: '9'
    MaxLength: '18'
    Default: 0.0.0.0/0
    AllowedPattern: '^(\d{1,3}\.){3}\d{1,3}/\d{1,2}$'
    ConstraintDescription: must be a valid IP CIDR range of the form x.x.x.x/x.

Resources:
  WebServerSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow HTTP access via my IP address
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: !Ref MyIP

  WebServer:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: !Ref LatestAmiId
      InstanceType: !Ref InstanceType
      SecurityGroupIds:
        - !Ref WebServerSecurityGroup
      UserData: !Base64 |
        #!/bin/bash
        yum update -y
        yum install -y httpd
        systemctl start httpd
        systemctl enable httpd
        echo "<html><body><h1>Hello World!</h1></body></html>" > /var/www/html/index.html

Outputs:
  WebsiteURL:
    Value: !Join
      - ''
      - - http://
        - !GetAtt WebServer.PublicDnsName
    Description: Website URL
EOF

if [ ! -f "$TEMPLATE_FILE" ]; then
    handle_error "Failed to create template file"
fi

# Step 2: Validate the template
echo ""
echo "Validating CloudFormation template..."
VALIDATION_RESULT=$(aws cloudformation validate-template --template-body "file://$TEMPLATE_FILE" 2>&1)
if [ $? -ne 0 ]; then
    handle_error "Template validation failed: $VALIDATION_RESULT"
fi
echo "Template validation successful."

# Step 3: Get the user's public IP address
echo ""
echo "Retrieving your public IP address..."
MY_IP=$(curl -s https://checkip.amazonaws.com)
if [ -z "$MY_IP" ]; then
    handle_error "Failed to retrieve public IP address"
fi
MY_IP="${MY_IP}/32"
echo "Your public IP address: $MY_IP"

# Step 4: Create the CloudFormation stack
echo ""
echo "Creating CloudFormation stack: $STACK_NAME"
echo "This will create an EC2 instance and security group."
CREATE_RESULT=$(aws cloudformation create-stack \
  --stack-name "$STACK_NAME" \
  --template-body "file://$TEMPLATE_FILE" \
  --parameters \
    ParameterKey=InstanceType,ParameterValue=t2.micro \
    ParameterKey=MyIP,ParameterValue="$MY_IP" \
  --output text 2>&1)

if [ $? -ne 0 ]; then
    handle_error "Stack creation failed: $CREATE_RESULT"
fi

STACK_ID=$(echo "$CREATE_RESULT" | tr -d '\r\n')
echo "Stack creation initiated. Stack ID: $STACK_ID"

# Step 5: Monitor stack creation
echo ""
echo "Monitoring stack creation..."
echo "This may take a few minutes."

# Wait for stack creation to complete
aws cloudformation wait stack-create-complete --stack-name "$STACK_NAME"
if [ $? -ne 0 ]; then
    # Check if the stack exists and get its status
    STACK_STATUS=$(aws cloudformation describe-stacks --stack-name "$STACK_NAME" --query "Stacks[0].StackStatus" --output text 2>/dev/null)
    if [ $? -ne 0 ] || [ "$STACK_STATUS" == "ROLLBACK_COMPLETE" ] || [ "$STACK_STATUS" == "ROLLBACK_IN_PROGRESS" ]; then
        handle_error "Stack creation failed. Status: $STACK_STATUS"
    fi
fi

echo "Stack creation completed successfully."

# Step 6: List stack resources
echo ""
echo "Resources created by the stack:"
aws cloudformation list-stack-resources --stack-name "$STACK_NAME" --query "StackResourceSummaries[*].{LogicalID:LogicalResourceId, Type:ResourceType, Status:ResourceStatus}" --output table

# Step 7: Get stack outputs
echo ""
echo "Stack outputs:"
OUTPUTS=$(aws cloudformation describe-stacks --stack-name "$STACK_NAME" --query "Stacks[0].Outputs" --output json)
if [ $? -ne 0 ]; then
    handle_error "Failed to retrieve stack outputs"
fi

# Extract the WebsiteURL
WEBSITE_URL=$(aws cloudformation describe-stacks --stack-name "$STACK_NAME" --query "Stacks[0].Outputs[?OutputKey=='WebsiteURL'].OutputValue" --output text)
if [ -z "$WEBSITE_URL" ]; then
    handle_error "Failed to extract WebsiteURL from stack outputs"
fi

echo "WebsiteURL: $WEBSITE_URL"
echo ""
echo "You can access the web server by opening the above URL in your browser."
echo "You should see a simple 'Hello World!' message."

# Step 8: Test the connection via CLI
echo ""
echo "Testing connection to the web server..."
HTTP_RESPONSE=$(curl -s -o /dev/null -w "%{http_code}" "$WEBSITE_URL")
if [ "$HTTP_RESPONSE" == "200" ]; then
    echo "Connection successful! HTTP status code: $HTTP_RESPONSE"
else
    echo "Warning: Connection test returned HTTP status code: $HTTP_RESPONSE"
    echo "The web server might not be ready yet or there might be connectivity issues."
fi

# Step 9: Prompt for cleanup
echo ""
echo "==================================================="
echo "CLEANUP CONFIRMATION"
echo "==================================================="
echo "Resources created:"
echo "- CloudFormation stack: $STACK_NAME"
echo "  - EC2 instance"
echo "  - Security group"
echo ""
echo "Do you want to clean up all created resources? (y/n): "
read -r CLEANUP_CHOICE

if [[ "$CLEANUP_CHOICE" =~ ^[Yy]$ ]]; then
    cleanup
else
    echo ""
    echo "Resources were not cleaned up. You can delete them later with:"
    echo "aws cloudformation delete-stack --stack-name $STACK_NAME"
    echo ""
    echo "Note: You may be charged for AWS resources as long as they exist."
fi

echo ""
echo "==================================================="
echo "Tutorial completed at: $(date)"
echo "Log file: $LOG_FILE"
echo "==================================================="