CloudFormation

Protocol: Query (XML) — POST http://localhost:4566/ with Action= parameter Endpoint: POST http://localhost:4566/

Supported Actions

Action	Description
CreateStack	Deploy a CloudFormation template
UpdateStack	Update an existing stack
DeleteStack	Delete a stack and its resources
DescribeStacks	Get stack status and outputs
ListStacks	List stacks by status
DescribeStackEvents	Get stack creation/update event history
DescribeStackResources	Get all resources in a stack
DescribeStackResource	Get a specific stack resource
ListStackResources	List resource summaries
GetTemplate	Retrieve the template body
ValidateTemplate	Validate a template without deploying
CreateChangeSet	Create a change set
DescribeChangeSet	Get change set details
ExecuteChangeSet	Apply a change set
ListChangeSets	List change sets for a stack
DeleteChangeSet	Delete a change set
SetStackPolicy	Set a stack policy
GetStackPolicy	Retrieve the current stack policy
ListStackSets	List StackSets
DescribeStackSet	Get StackSet details
CreateStackSet	Create a new StackSet

Supported Resource Types

Resource types provisioned during CreateStack / UpdateStack / DeleteStack:

Resource Type	Notes
AWS::S3::Bucket
AWS::S3::BucketPolicy	Accepted; policy not enforced
AWS::SQS::Queue
AWS::SQS::QueuePolicy	Accepted; policy not enforced
AWS::SNS::Topic
AWS::DynamoDB::Table
AWS::DynamoDB::GlobalTable
AWS::Lambda::Function	Zip (S3 or inline ZipFile) and Image package types
AWS::Lambda::EventSourceMapping	SQS, Kinesis, and DynamoDB Streams sources
AWS::IAM::Role
AWS::IAM::User
AWS::IAM::AccessKey
AWS::IAM::Policy
AWS::IAM::ManagedPolicy
AWS::IAM::InstanceProfile
AWS::SSM::Parameter
AWS::KMS::Key
AWS::KMS::Alias
AWS::SecretsManager::Secret
AWS::ECR::Repository
AWS::Events::Rule
AWS::ApiGateway::RestApi
AWS::ApiGateway::Resource
AWS::ApiGateway::Method
AWS::ApiGateway::Deployment
AWS::ApiGateway::Stage
AWS::ApiGatewayV2::Api
AWS::ApiGatewayV2::Route
AWS::ApiGatewayV2::Integration
AWS::ApiGatewayV2::Stage
AWS::ApiGatewayV2::Deployment
AWS::Pipes::Pipe
AWS::CloudFormation::Stack	Nested stacks (stubbed — returns synthetic stack ID)
AWS::CDK::Metadata	Accepted; no-op
AWS::Route53::HostedZone	Stubbed
AWS::Route53::RecordSet	Stubbed

All other resource types are accepted without error and assigned a synthetic physical ID, so templates with unsupported types still deploy rather than fail.

Lambda Stack Updates

AWS::Lambda::Function resources are reconciled during UpdateStack in the same shape as CloudFormation/CDK deployments:

• A no-op redeploy keeps the existing physical function name and does not call Lambda update APIs, so warm containers can be reused.
• Code and mutable configuration changes update the existing function in place.
• Replacement-only changes such as FunctionName or PackageType changes create a replacement function and remove the old one.
• S3-backed code stays linked through S3Bucket / S3Key, so Lambda's reactive S3 sync continues to work for functions created by CloudFormation or CDK.

Configuration

Variable	Default	Description
FLOCI_SERVICES_CLOUDFORMATION_ENABLED	true	Enable or disable the service

Examples

export AWS_ENDPOINT_URL=http://localhost:4566

# Validate a template
aws cloudformation validate-template \
  --template-body file://template.yml \
  --endpoint-url $AWS_ENDPOINT_URL

# Deploy a stack
aws cloudformation create-stack \
  --stack-name my-stack \
  --template-body file://template.yml \
  --parameters ParameterKey=Env,ParameterValue=dev \
  --endpoint-url $AWS_ENDPOINT_URL

# Check status
aws cloudformation describe-stacks \
  --stack-name my-stack \
  --endpoint-url $AWS_ENDPOINT_URL

# Watch events
aws cloudformation describe-stack-events \
  --stack-name my-stack \
  --endpoint-url $AWS_ENDPOINT_URL

# Update
aws cloudformation update-stack \
  --stack-name my-stack \
  --template-body file://template.yml \
  --endpoint-url $AWS_ENDPOINT_URL

# Delete
aws cloudformation delete-stack \
  --stack-name my-stack \
  --endpoint-url $AWS_ENDPOINT_URL

# Create a change set
aws cloudformation create-change-set \
  --stack-name my-stack \
  --change-set-name my-change-set \
  --template-body file://template.yml \
  --endpoint-url $AWS_ENDPOINT_URL

# List change sets
aws cloudformation list-change-sets \
  --stack-name my-stack \
  --endpoint-url $AWS_ENDPOINT_URL

# Describe a change set
aws cloudformation describe-change-set \
  --stack-name my-stack \
  --change-set-name my-change-set \
  --endpoint-url $AWS_ENDPOINT_URL

# Delete a change set
aws cloudformation delete-change-set \
  --stack-name my-stack \
  --change-set-name my-change-set \
  --endpoint-url $AWS_ENDPOINT_URL

Lambda + SQS Event Source Mapping

Deploy a Lambda function wired to an SQS queue as a single stack:

# template.yml
Resources:
  MyQueue:
    Type: AWS::SQS::Queue
    Properties:
      QueueName: my-queue

  MyFunction:
    Type: AWS::Lambda::Function
    Properties:
      FunctionName: my-function
      Runtime: nodejs22.x
      Handler: index.handler
      Role: arn:aws:iam::000000000000:role/lambda-role
      Code:
        ZipFile: |
          exports.handler = async (event) => {
            console.log(JSON.stringify(event));
          };

  MyESM:
    Type: AWS::Lambda::EventSourceMapping
    Properties:
      FunctionName: !Ref MyFunction
      EventSourceArn: !GetAtt MyQueue.Arn
      Enabled: true
      BatchSize: 10

aws cloudformation create-stack \
  --stack-name my-lambda-sqs-stack \
  --template-body file://template.yml \
  --endpoint-url $AWS_ENDPOINT_URL

Dependency ordering

Use !Ref MyFunction (not a plain string) for FunctionName so CloudFormation provisions the function before the event source mapping.