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In this step-by-step guide you’ll author a minimal CloudFormation YAML template and use the AWS CLI to provision an S3 bucket and an EC2 instance. The workflow is intentionally simple so you can quickly learn the end-to-end process: write the template, create the stack with the CLI, verify the resources in the console, and then clean up.
Before you begin, ensure the AWS CLI is installed and configured with credentials that have permissions to create CloudFormation stacks, EC2 instances, and S3 buckets. Configure the CLI with aws configure or set the credentials via environment variables.

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What you’ll create

  • CloudFormation stack named simple-s3-ec2-stack
  • An Amazon S3 bucket (name generated by CloudFormation)
  • An Amazon EC2 instance (AMI selected via a region map)

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CloudFormation template (cli.yaml)

Create a file named cli.yaml in a project folder (for example, cf-project). This minimal template includes:
  • A Mappings section with AMI IDs for a few regions
  • A Parameter to control instance type (default: t3.micro)
  • An S3 bucket resource
  • An EC2 instance that selects the AMI using the Region map and intrinsic functions
Save the following YAML as cli.yaml: 
AWSTemplateFormatVersion: '2010-09-09'
Description: Basic EC2 instance with S3 bucket

Mappings:
  RegionMap:
    us-east-2:
      AMI: ami-0eb9d6fc9fab44d24
    eu-west-1:
      AMI: ami-0b3e7dd7b2a99b08d
    us-east-1:
      AMI: ami-0150ccaf51ab55a51

Parameters:
  MyInstanceType:
    Type: String
    Default: t3.micro
    Description: EC2 instance type

Resources:
  MyBucket:
    Type: AWS::S3::Bucket

  MyInstance:
    Type: AWS::EC2::Instance
    Properties:
      InstanceType: !Ref MyInstanceType
      ImageId: !FindInMap [RegionMap, !Ref "AWS::Region", AMI]
This template uses intrinsic functions (!Ref, !FindInMap) so the AMI is chosen automatically based on the region where the stack is created.

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Change to your project directory

Open a terminal and change into the folder containing cli.yaml. Windows (Command Prompt or PowerShell): 
C:\Users\Arno> cd Desktop\cf-project
macOS / Linux: 
$ cd ~/Desktop/cf-project
(Optional) Clear the terminal with cls (Windows) or clear (macOS/Linux).

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Create the CloudFormation stack using the AWS CLI

Run the create-stack command and set the target region (example uses us-east-2): 
aws cloudformation create-stack \
  --stack-name simple-s3-ec2-stack \
  --template-body file://cli.yaml \
  --region us-east-2
If successful, the CLI returns a StackId similar to: 
StackId: arn:aws:cloudformation:us-east-2:635573991785:stack/simple-s3-ec2-stack/a00c6a70-5f86-11f0-918b-062d83e2b7d9
CloudFormation will take a minute or two to provision resources. Monitor progress either in the CloudFormation console or via the CLI: 
aws cloudformation describe-stacks --stack-name simple-s3-ec2-stack --region us-east-2
You can also list in-progress events in the console to see creation steps and any errors.

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Verify resources in the AWS Console

  • CloudFormation console — view stack events and the resources created by the stack.
  • S3 console (region us-east-2) — find the bucket created by the stack (CloudFormation generates a name when none is provided).
  • EC2 console (region us-east-2) — confirm the instance is running and was launched from the AMI defined in the region mapping.
There is one running instance created by this stack, as shown in the EC2 console:
A screenshot of the AWS EC2 dashboard (US East — Ohio) showing the Resources panel with items like Instances (running): 1, Security groups: 1, Volumes: 1, etc. The browser window shows multiple open tabs and the Windows taskbar at the bottom.
And here is the S3 console showing the bucket created in the US East (Ohio) region:
A screenshot of the Amazon S3 console showing a "General purpose buckets" list with three buckets in the US East (Ohio) region, their names and creation dates. The page also shows IAM Access Analyzer links and a prominent "Create bucket" button.
To inspect stack resources from the CLI: 
aws cloudformation list-stack-resources --stack-name simple-s3-ec2-stack --region us-east-2

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Cleanup — delete the stack and resources

When you’re done, delete the CloudFormation stack to remove all resources it created: 
aws cloudformation delete-stack --stack-name simple-s3-ec2-stack --region us-east-2
Check deletion status with: 
aws cloudformation describe-stacks --stack-name simple-s3-ec2-stack --region us-east-2
# or monitor the CloudFormation console until the stack is removed
Notes about deletion:
  • CloudFormation deletes the S3 bucket and EC2 instance it created unless the bucket contains objects you uploaded manually. Objects in an S3 bucket prevent its automatic deletion.
  • If you created temporary access keys for this demo, deactivate and delete them to reduce security risk.
Example CLI commands to deactivate and delete an access key (replace placeholders): 
aws iam update-access-key --user-name <USER_NAME> --access-key-id <ACCESS_KEY_ID> --status Inactive
aws iam delete-access-key --user-name <USER_NAME> --access-key-id <ACCESS_KEY_ID>
Be careful when deleting stacks—confirm you are deleting the correct stack and verify there are no important objects in S3 buckets. Deletion can cause irreversible data loss and objects may block the stack from being removed.

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Quick reference

ActionCLI commandNotes
Create stackaws cloudformation create-stack --stack-name simple-s3-ec2-stack --template-body file://cli.yaml --region <region>Use --region to control where resources are created
Describe stackaws cloudformation describe-stacks --stack-name simple-s3-ec2-stack --region <region>Check status and outputs
List stack resourcesaws cloudformation list-stack-resources --stack-name simple-s3-ec2-stack --region <region>Lists logical/physical IDs
Delete stackaws cloudformation delete-stack --stack-name simple-s3-ec2-stack --region <region>Removes resources created by the stack

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Summary

  • Author a minimal CloudFormation YAML template (cli.yaml) defining an S3 bucket and EC2 instance.
  • Use the AWS CLI to create the stack: aws cloudformation create-stack --stack-name ... --template-body file://cli.yaml --region <region>.
  • Verify the resources in the CloudFormation, S3, and EC2 consoles.
  • Delete the stack to clean up resources and remove any temporary access keys.
That completes this demo on using CloudFormation with the AWS CLI to provision an S3 bucket and an EC2 instance.

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