AWS::ServiceDiscovery::Instance - AWS CloudFormation
SyntaxPropertiesReturn valuesExamplesSee also

AWS::ServiceDiscovery::Instance

A complex type that contains information about an instance that AWS Cloud Map creates when you submit a RegisterInstance request.

Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

JSON

{
  "Type" : "AWS::ServiceDiscovery::Instance",
  "Properties" : {
      "InstanceAttributes" : Json,
      "InstanceId" : String,
      "ServiceId" : String
    }
}

YAML

Type: AWS::ServiceDiscovery::Instance
Properties:
  InstanceAttributes: Json
  InstanceId: String
  ServiceId: String

Properties

InstanceAttributes

A string map that contains the following information for the service that you specify in ServiceId:

  • The attributes that apply to the records that are defined in the service.

  • For each attribute, the applicable value.

Supported attribute keys include the following:

AWS_ALIAS_DNS_NAME

If you want AWS Cloud Map to create a Route 53 alias record that routes traffic to an Elastic Load Balancing load balancer, specify the DNS name that is associated with the load balancer. For information about how to get the DNS name, see AliasTarget->DNSName in the Route 53 API Reference.

Note the following:

  • The configuration for the service that is specified by ServiceId must include settings for an A record, an AAAA record, or both.

  • In the service that is specified by ServiceId, the value of RoutingPolicy must be WEIGHTED.

  • If the service that is specified by ServiceId includes HealthCheckConfig settings, AWS Cloud Map will create the health check, but it won't associate the health check with the alias record.

  • Auto naming currently doesn't support creating alias records that route traffic to AWS resources other than ELB load balancers.

  • If you specify a value for AWS_ALIAS_DNS_NAME, don't specify values for any of the AWS_INSTANCE attributes.

AWS_EC2_INSTANCE_ID

HTTP namespaces only. The Amazon EC2 instance ID for the instance. The AWS_INSTANCE_IPV4 attribute contains the primary private IPv4 address. When creating resources with a type of AWS::ServiceDiscovery::Instance, if the AWS_EC2_INSTANCE_ID attribute is specified, the only other attribute that can be specified is AWS_INIT_HEALTH_STATUS. After the resource has been created, the AWS_INSTANCE_IPV4 attribute contains the primary private IPv4 address.

AWS_INIT_HEALTH_STATUS

If the service configuration includes HealthCheckCustomConfig, when creating resources with a type of AWS::ServiceDiscovery::Instance you can optionally use AWS_INIT_HEALTH_STATUS to specify the initial status of the custom health check, HEALTHY or UNHEALTHY. If you don't specify a value for AWS_INIT_HEALTH_STATUS, the initial status is HEALTHY. This attribute can only be used when creating resources and will not be seen on existing resources.

AWS_INSTANCE_CNAME

If the service configuration includes a CNAME record, the domain name that you want Route 53 to return in response to DNS queries, for example, example.com.

This value is required if the service specified by ServiceId includes settings for an CNAME record.

AWS_INSTANCE_IPV4

If the service configuration includes an A record, the IPv4 address that you want Route 53 to return in response to DNS queries, for example, 192.0.2.44.

This value is required if the service specified by ServiceId includes settings for an A record. If the service includes settings for an SRV record, you must specify a value for AWS_INSTANCE_IPV4, AWS_INSTANCE_IPV6, or both.

AWS_INSTANCE_IPV6

If the service configuration includes an AAAA record, the IPv6 address that you want Route 53 to return in response to DNS queries, for example, 2001:0db8:85a3:0000:0000:abcd:0001:2345.

This value is required if the service specified by ServiceId includes settings for an AAAA record. If the service includes settings for an SRV record, you must specify a value for AWS_INSTANCE_IPV4, AWS_INSTANCE_IPV6, or both.

AWS_INSTANCE_PORT

If the service includes an SRV record, the value that you want Route 53 to return for the port.

If the service includes HealthCheckConfig, the port on the endpoint that you want Route 53 to send requests to.

This value is required if you specified settings for an SRV record or a Route 53 health check when you created the service.

Required: Yes

Type: Json

Update requires: No interruption

InstanceId

An identifier that you want to associate with the instance. Note the following:

  • If the service that's specified by ServiceId includes settings for an SRV record, the value of InstanceId is automatically included as part of the value for the SRV record. For more information, see DnsRecord > Type.

  • You can use this value to update an existing instance.

  • To register a new instance, you must specify a value that's unique among instances that you register by using the same service.

  • If you specify an existing InstanceId and ServiceId, AWS Cloud Map updates the existing DNS records, if any. If there's also an existing health check, AWS Cloud Map deletes the old health check and creates a new one.

    Note

    The health check isn't deleted immediately, so it will still appear for a while if you submit a ListHealthChecks request, for example.

Note

Do not include sensitive information in InstanceId if the namespace is discoverable by public DNS queries and any Type member of DnsRecord for the service contains SRV because the InstanceId is discoverable by public DNS queries.

Required: No

Type: String

Pattern: ^[0-9a-zA-Z_/:.@-]+$

Maximum: 64

Update requires: Replacement

ServiceId

The ID of the service that you want to use for settings for the instance.

Required: Yes

Type: String

Maximum: 64

Update requires: Replacement

Return values

Ref

When you pass the logical ID of this resource to the intrinsic Ref function, Ref returns the value of Id for the instance, such as i-abcd1234.

For more information about using the Ref function, see Ref.

Fn::GetAtt

InstanceId

The ID of an instance that matches the values that you specified in the request.

Examples

Use custom attributes to register resources

The following example registers application resources like a DynamoDB table and Lambda functions as instances using the table and function names as custom attributes. The Lambda functions also have an action custom attribute used to distinguish the read function from the write function. The DynamoDB table is registered using the service that has the ID srv-e3anhexample0003. The read and write Lambda functions are registered using the service that has the ID srv-e4anhexample0004. This example is based on the tutorial Learn how to use AWS Cloud Map service discovery with custom attributes in the AWS Cloud Map Developer Guide.

JSON

{
  "Resources": {
    "ReadInstance": {
      "Type": "AWS::ServiceDiscovery::Instance",
      "Properties": {
        "InstanceAttributes": {
          "functionname": "readfunction",
          "action": "read"
        },
        "InstanceId": "read-instance",
        "ServiceId": "srv-e4anhexample0004"
      }
    },
    "WriteInstance": {
      "Type": "AWS::ServiceDiscovery::Instance",
      "Properties": {
        "InstanceAttributes": {
          "functionname": "writefunction",
          "action": "write"
        },
        "InstanceId": "write-instance",
        "ServiceId": "srv-e4anhexample0004"
      }
    },
    "DataInstance": {
      "Type": "AWS::ServiceDiscovery::Instance",
      "Properties": {
        "InstanceAttributes": {
          "tablename": "cloudmap"
        },
        "InstanceId": "data-instance",
        "ServiceId": "srv-e3anhexample0003"
      }
    }
  }
}

YAML

Resources:
  ReadInstance:
    Type: AWS::ServiceDiscovery::Instance
    Properties:
      InstanceAttributes:
        functionname: readfunction
        action: read
      InstanceId: read-instance   
      ServiceId: srv-e4anhexample0004
  WriteInstance:
    Type: AWS::ServiceDiscovery::Instance
    Properties:
      InstanceAttributes:
        functionname: writefunction
        action: write
      InstanceId: write-instance 
      ServiceId: srv-e4anhexample0004
  DataInstance:
    Type: AWS::ServiceDiscovery::Instance
    Properties:
      InstanceAttributes:
        tablename: cloudmap
      InstanceId: data-instance  
      ServiceId: srv-e3anhexample0003

Provide IP addresses for an instance

The following example provides IPv4 and IPV6 IP addresses for the instance that has an ID of i-abcd1234. The instance was registered using the service that has an ID of srv-e4anhexample0004.

JSON

{
    "Resources": {
        "Instance": {
            "Type": "AWS::ServiceDiscovery::Instance",
            "Properties": {
                "InstanceAttributes": {
                    "AWS_INSTANCE_IPV4": "192.0.2.44",
                    "AWS_INSTANCE_IPV6": "2001:0db8:85a3:0000:0000:abcd:0001:2345"
                },
                "InstanceId": "i-abcd1234",
                "ServiceId": "srv-e4anhexample0004"
            }
        }
    }
}

YAML

Resources:
  Instance:
    Type: AWS::ServiceDiscovery::Instance
    Properties:
      InstanceAttributes:
        AWS_INSTANCE_IPV4: 192.0.2.44
        AWS_INSTANCE_IPV6: 2001:0db8:85a3:0000:0000:abcd:0001:2345
      InstanceId: i-abcd1234
      ServiceId: srv-e4anhexample0004

See also