以下是一个使用AWS CloudFormation创建AWS ECS集群和服务的示例代码：

{
  "AWSTemplateFormatVersion": "2010-09-09",
  "Resources": {
    "ECSCluster": {
      "Type": "AWS::ECS::Cluster"
    },
    "ECSService": {
      "Type": "AWS::ECS::Service",
      "Properties": {
        "Cluster": {
          "Ref": "ECSCluster"
        },
        "TaskDefinition": "your-task-definition-arn",
        "DesiredCount": 2,
        "LaunchType": "FARGATE",
        "NetworkConfiguration": {
          "AwsvpcConfiguration": {
            "AssignPublicIp": "ENABLED",
            "SecurityGroups": [
              "your-security-group-id"
            ],
            "Subnets": [
              "your-subnet-1",
              "your-subnet-2"
            ]
          }
        }
      }
    }
  }
}

以上代码创建一个AWS ECS集群和一个服务。要使用此模板，您需要将your-task-definition-arn替换为您的任务定义的ARN，your-security-group-id替换为您的安全组的ID，your-subnet-1和your-subnet-2替换为您的子网ID。

您可以使用AWS CloudFormation控制台、AWS CLI或AWS SDK来部署此CloudFormation模板。