Sample CloudFormation JSON to create an AWS EC2 instance

  • Release version: Zurich
  • Updated July 31, 2025
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    Summary of Sample CloudFormation JSON to create an AWS EC2 instance

    This CloudFormation JSON template enables you to deploy an Amazon EC2 instance running the Amazon Linux AMI. It is designed for use within ServiceNow to automate provisioning through catalog items. The template includes creation of a security group configured to allow SSH access on port 22, with the AMI dynamically selected based on the AWS region and instance type architecture.

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    Before deploying, review the template to identify provisioned AWS services and ensure necessary permissions are granted to avoid stack creation failures.

    Key Features

    • Parameter-driven configuration: Customize EC2 instance parameters such as KeyName (existing EC2 KeyPair for SSH), InstanceType (with a broad selection of valid EC2 types), SSHLocation (CIDR range allowed for SSH), Network, AvailabilityZone, and SubnetPool.
    • Dynamic AMI selection: Uses mappings to select the correct AMI ID based on region and architecture type associated with the chosen instance type.
    • Security group setup: Automatically creates a security group permitting inbound SSH access from the specified IP range.
    • ServiceNow integration: Metadata includes datasource references to ServiceNow pools for KeyPairs, Networks, and SubnetPools ensuring seamless catalog integration.

    Practical Use and Considerations

    • Use this template as a reference or baseline when designing catalog items to provision EC2 instances.
    • Modify parameters such as KeyName, InstanceType, and SSHLocation according to your security policies and infrastructure setup.
    • Ensure that the ServiceNow user or role executing the stack has appropriate AWS permissions configured, especially for EC2 instance launch and security group management.
    • Be aware that this template will incur AWS charges for the resources created.

    Expected Outcomes

    • Automated deployment of an EC2 instance with SSH access enabled through a security group.
    • Outputs providing the EC2 instance ID and its availability zone for tracking and integration with other ServiceNow processes.

    Reference code sample to deploy an Amazon AWS Cloud EC2 instance.

    Deploying an AWS EC2 instance using CloudFormation

    • While designing a catalog item, review the cloud formation template to identify the services that are being provisioned. Check that appropriate permissions for the services can be granted, to ensure that no failures occur from lack of permissions when the stack is ordered. For more information, see Configure permissions on the AWS console
    • Make necessary modifications using this sample as your reference. 
    {
   "AWSTemplateFormatVersion":"2010-09-09",
   "Description":"AWS CloudFormation Sample Template EC2InstanceWithSecurityGroupSample: Create an Amazon EC2 instance running the Amazon Linux AMI. The AMI is chosen based on the region in which the stack is run. This example creates an EC2 security group for the instance to give you SSH access. **WARNING** This template creates an Amazon EC2 instance. You will be billed for the AWS resources used if you create a stack from this template.",
   "Parameters":{
      "KeyName":{
         "Description":"Name of an existing EC2 KeyPair to enable SSH access to the instance",
         "Type":"AWS::EC2::KeyPair::KeyName",
         "Default":"admin-Default",
         "ConstraintDescription":"must be the name of an existing EC2 KeyPair."
      },
      "InstanceType":{
         "Description":"WebServer EC2 instance type",
         "Type":"String",
         "Default":"t2.micro",
         "AllowedValues":[
            "t1.micro",
            "t2.nano",
            "t2.micro",
            "t2.small",
            "t2.medium",
            "t2.large",
            "m1.small",
            "m1.medium",
            "m1.large",
            "m1.xlarge",
            "m2.xlarge",
            "m2.2xlarge",
            "m2.4xlarge",
            "m3.medium",
            "m3.large",
            "m3.xlarge",
            "m3.2xlarge",
            "m4.large",
            "m4.xlarge",
            "m4.2xlarge",
            "m4.4xlarge",
            "m4.10xlarge",
            "c1.medium",
            "c1.xlarge",
            "c3.large",
            "c3.xlarge",
            "c3.2xlarge",
            "c3.4xlarge",
            "c3.8xlarge",
            "c4.large",
            "c4.xlarge",
            "c4.2xlarge",
            "c4.4xlarge",
            "c4.8xlarge",
            "g2.2xlarge",
            "g2.8xlarge",
            "r3.large",
            "r3.xlarge",
            "r3.2xlarge",
            "r3.4xlarge",
            "r3.8xlarge",
            "i2.xlarge",
            "i2.2xlarge",
            "i2.4xlarge",
            "i2.8xlarge",
            "d2.xlarge",
            "d2.2xlarge",
            "d2.4xlarge",
            "d2.8xlarge",
            "hi1.4xlarge",
            "hs1.8xlarge",
            "cr1.8xlarge",
            "cc2.8xlarge",
            "cg1.4xlarge"
         ],
         "ConstraintDescription":"must be a valid EC2 instance type."
      },
      "SSHLocation":{
         "Description":"The IP address range that can be used to SSH to the EC2 instances",
         "Type":"String",
         "MinLength":"9",
         "MaxLength":"18",
         "Default":"0.0.0.0/0",
         "AllowedPattern":"(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})/(\\d{1,2})",
         "ConstraintDescription":"must be a valid IP CIDR range of the form x.x.x.x/x."
      },
      "Network":{
         "Description":"The Network to the EC2 instances",
         "Type":"String"
      },
      "AvailabilityZone":{
         "Description":"The AZ of the EC2 instance",
         "Type":"String"
      },
      "SubnetPool":{
         "Description":"The IP address range that can be used to SSH to the EC2 instances",
         "Type":"String"
      }
   },
   "Metadata":{
      "SNC::Parameter::Metadata":{
         "SubnetPool":{
            "datasource":"ServiceNow::Pools::SubnetPool.getObjectsByNetwork",
            "datasourceFilter":{
               "Network":"Network"
            }
         },
         "Network":{
            "datasource":"ServiceNow::Pools::NetworkPool.getObjectsByLDC"
         },
         "KeyName":{
            "datasource":"ServiceNow::Pools::CloudKeyPairPool.getObjectsByLDC"
         }
      }
   },
   "Mappings":{
      "AWSInstanceType2Arch":{
         "t1.micro":{
            "Arch":"PV64"
         },
         "t2.nano":{
            "Arch":"HVM64"
         },
         "t2.micro":{
            "Arch":"HVM64"
         },
         "t2.small":{
            "Arch":"HVM64"
         },
         "t2.medium":{
            "Arch":"HVM64"
         },
         "t2.large":{
            "Arch":"HVM64"
         },
         "m1.small":{
            "Arch":"PV64"
         },
         "m1.medium":{
            "Arch":"PV64"
         },
         "m1.large":{
            "Arch":"PV64"
         },
         "m1.xlarge":{
            "Arch":"PV64"
         },
         "m2.xlarge":{
            "Arch":"PV64"
         },
         "m2.2xlarge":{
            "Arch":"PV64"
         },
         "m2.4xlarge":{
            "Arch":"PV64"
         },
         "m3.medium":{
            "Arch":"HVM64"
         },
         "m3.large":{
            "Arch":"HVM64"
         },
         "m3.xlarge":{
            "Arch":"HVM64"
         },
         "m3.2xlarge":{
            "Arch":"HVM64"
         },
         "m4.large":{
            "Arch":"HVM64"
         },
         "m4.xlarge":{
            "Arch":"HVM64"
         },
         "m4.2xlarge":{
            "Arch":"HVM64"
         },
         "m4.4xlarge":{
            "Arch":"HVM64"
         },
         "m4.10xlarge":{
            "Arch":"HVM64"
         },
         "c1.medium":{
            "Arch":"PV64"
         },
         "c1.xlarge":{
            "Arch":"PV64"
         },
         "c3.large":{
            "Arch":"HVM64"
         },
         "c3.xlarge":{
            "Arch":"HVM64"
         },
         "c3.2xlarge":{
            "Arch":"HVM64"
         },
         "c3.4xlarge":{
            "Arch":"HVM64"
         },
         "c3.8xlarge":{
            "Arch":"HVM64"
         },
         "c4.large":{
            "Arch":"HVM64"
         },
         "c4.xlarge":{
            "Arch":"HVM64"
         },
         "c4.2xlarge":{
            "Arch":"HVM64"
         },
         "c4.4xlarge":{
            "Arch":"HVM64"
         },
         "c4.8xlarge":{
            "Arch":"HVM64"
         },
         "g2.2xlarge":{
            "Arch":"HVMG2"
         },
         "g2.8xlarge":{
            "Arch":"HVMG2"
         },
         "r3.large":{
            "Arch":"HVM64"
         },
         "r3.xlarge":{
            "Arch":"HVM64"
         },
         "r3.2xlarge":{
            "Arch":"HVM64"
         },
         "r3.4xlarge":{
            "Arch":"HVM64"
         },
         "r3.8xlarge":{
            "Arch":"HVM64"
         },
         "i2.xlarge":{
            "Arch":"HVM64"
         },
         "i2.2xlarge":{
            "Arch":"HVM64"
         },
         "i2.4xlarge":{
            "Arch":"HVM64"
         },
         "i2.8xlarge":{
            "Arch":"HVM64"
         },
         "d2.xlarge":{
            "Arch":"HVM64"
         },
         "d2.2xlarge":{
            "Arch":"HVM64"
         },
         "d2.4xlarge":{
            "Arch":"HVM64"
         },
         "d2.8xlarge":{
            "Arch":"HVM64"
         },
         "hi1.4xlarge":{
            "Arch":"HVM64"
         },
         "hs1.8xlarge":{
            "Arch":"HVM64"
         },
         "cr1.8xlarge":{
            "Arch":"HVM64"
         },
         "cc2.8xlarge":{
            "Arch":"HVM64"
         }
      },
      "AWSRegionArch2AMI":{
         "us-east-1":{
            "PV64":"ami-2a69aa47",
            "HVM64":"ami-6869aa05",
            "HVMG2":"ami-a41a3fb3"
         },
         "us-west-2":{
            "PV64":"ami-7f77b31f",
            "HVM64":"ami-7172b611",
            "HVMG2":"ami-caf253aa"
         },
         "us-west-1":{
            "PV64":"ami-a2490dc2",
            "HVM64":"ami-31490d51",
            "HVMG2":"ami-00347e60"
         },
         "eu-west-1":{
            "PV64":"ami-4cdd453f",
            "HVM64":"ami-f9dd458a",
            "HVMG2":"ami-e2f7bd91"
         },
         "eu-central-1":{
            "PV64":"ami-6527cf0a",
            "HVM64":"ami-ea26ce85",
            "HVMG2":"ami-d2ff04bd"
         },
         "ap-northeast-1":{
            "PV64":"ami-3e42b65f",
            "HVM64":"ami-374db956",
            "HVMG2":"ami-4c78d52d"
         },
         "ap-northeast-2":{
            "PV64":"NOT_SUPPORTED",
            "HVM64":"ami-2b408b45",
            "HVMG2":"NOT_SUPPORTED"
         },
         "ap-southeast-1":{
            "PV64":"ami-df9e4cbc",
            "HVM64":"ami-a59b49c6",
            "HVMG2":"ami-f3f95990"
         },
         "ap-southeast-2":{
            "PV64":"ami-63351d00",
            "HVM64":"ami-dc361ebf",
            "HVMG2":"ami-3a122e59"
         },
         "ap-south-1":{
            "PV64":"NOT_SUPPORTED",
            "HVM64":"ami-ffbdd790",
            "HVMG2":"ami-21a7d34e"
         },
         "us-east-2":{
            "PV64":"NOT_SUPPORTED",
            "HVM64":"ami-f6035893",
            "HVMG2":"NOT_SUPPORTED"
         },
         "sa-east-1":{
            "PV64":"ami-1ad34676",
            "HVM64":"ami-6dd04501",
            "HVMG2":"NOT_SUPPORTED"
         },
         "cn-north-1":{
            "PV64":"ami-77559f1a",
            "HVM64":"ami-8e6aa0e3",
            "HVMG2":"NOT_SUPPORTED"
         }
      }
   },
   "Resources":{
      "EC2Instance":{
         "Type":"AWS::EC2::Instance",
         "Properties":{
            "InstanceType":{
               "Ref":"InstanceType"
            },
            "KeyName":{
               "Ref":"KeyName"
            },
            "SubnetId":{
               "Ref":"SubnetPool"
            },
            "ImageId":{
               "Fn::FindInMap":[
                  "AWSRegionArch2AMI",
                  {
                     "Ref":"AWS::Region"
                  },
                  {
                     "Fn::FindInMap":[
                        "AWSInstanceType2Arch",
                        {
                           "Ref":"InstanceType"
                        },
                        "Arch"
                     ]
                  }
               ]
            }
         }
      },
      "InstanceSecurityGroup":{
         "Type":"AWS::EC2::SecurityGroup",
         "Properties":{
            "GroupDescription":"Enable SSH access via port 22",
            "SecurityGroupIngress":[
               {
                  "IpProtocol":"tcp",
                  "FromPort":"22",
                  "ToPort":"22",
                  "CidrIp":{
                     "Ref":"SSHLocation"
                  }
               }
            ]
         }
      }
   },
   "Outputs":{
      "InstanceId":{
         "Description":"InstanceId of the newly created EC2 instance",
         "Value":{
            "Ref":"EC2Instance"
         }
      },
      "AZ":{
         "Description":"Availability Zone of the newly created EC2 instance",
         "Value":{
            "Fn::GetAtt":[
               "EC2Instance",
               "AvailabilityZone"
            ]
         }
      }
   }
}