Creating a DNAT Rule Using a Specific ECS

Scenarios

This section describes how to create a DNAT rule by calling APIs. For details about how to call APIs, see Calling APIs.

Prerequisites

• You have created a VPC and a subnet. For details, see Virtual Private Cloud API Reference.
• Ensure that the VPC does not have a default route.
• You can create a rule only when status of the NAT gateway is ACTIVE and admin_state_up of the NAT gateway administrator is True.
• If you use a token for authentication, you must obtain the token and add X-Auth-Token to the request header when making an API call. Obtain the token by referring to Authentication.

The token obtained from IAM is valid for only 24 hours. If you want to use a token for authentication, you can cache it to avoid frequent calling.

Procedure

1. Create a NAT gateway.
   1. Determine the VPC to be used.
      • Query VPCs.

        URI format: GET /v1/{project_id}/vpcs

        For details, see "Querying VPCs" in the Virtual Private Cloud API Reference.

      • Select a VPC that does not have a default route, and make a note of the VPC ID.
   2. Determine the subnet in the VPC to be used.
      • Query the subnets in the VPC.

        URI format: GET /v1/{project_id}/subnets?vpc_id={vpc_id}

        For details, see "Querying Subnets" in the Virtual Private Cloud API Reference.

      • Select a subnet based on service requirements and make a note of the subnet ID.
   3. Create a NAT gateway.
      • API

        URI format: POST /v2/{project_id}/nat_gateways

        For details, see Creating a NAT Gateway.

      • Example request

        POST https://{Endpoint}/v2/27e25061336f4af590faeabeb7fcd9a3/nat_gateways

        Obtain {endpoint} from Regions and Endpoints.

      • Example response

      {  
          "nat_gateway": {  
              "router_id": "d84f345c-80a1-4fa2-a39c-d0d397c3f09a",  
              "status": "PENDING_CREATE",  
              "description": "my nat gateway 01",  
              "admin_state_up": true,  
              "tenant_id": "27e25061336f4af590faeabeb7fcd9a3",  
              "created_at": "2017-11-18 07:34:32.203044",  
              "spec": "1",  
              "internal_network_id": "89d66639-aacb-4929-969d-07080b0f9fd9",  
              "id": "a78fb3eb-1654-4710-8742-3fc49d5f04f8",  
              "name": "nat_001", 
              "dnat_rules_limit": "200", 
              "snat_rule_public_ip_limit": "20", 
              "enterprise_project_id": "0aad99bc-f5f6-4f78-8404-c598d76b0ed2", 
              "billing_info": "" 
          }  
      }

   4. Ensure that the NAT gateway is successfully created and is in the active state.

      API

      URI format: GET /v2/{project_id}/nat_gateways/{nat_gateway_id}

      For details, see Querying Details About a Specified NAT Gateway.

   5. Make a note of the NAT gateway ID and the value of internal_network_id.

2. Determine the ECS to be used.
   1. Query ECSs.

      API

      URI format: GET https://{endpoint}/v1/{project_id}/cloudservers/detail

      For details, see "Querying Details About ECSs" in the Elastic Cloud Server API Reference.

   2. Select an ECS based on service requirements and make a note of the port ID of the ECS NIC.

3. Determine the EIP to be used.
   1. Query EIPs.

      API

      URI format: GET /v1/{project_id}/publicips

      For details, see "Querying EIPs" in the Elastic IP API Reference.

   2. Select an EIP based on service requirements and make a note of the EIP ID.

4. Create a DNAT rule.
   • API

     URI format: POST /v2/{project_id}/dnat_rules

     For details, see Creating a DNAT Rule.

   • Example request

     POST https://{Endpoint}/v2/27e25061336f4af590faeabeb7fcd9a3/dnat_rules

     Obtain {endpoint} from Regions and Endpoints.

     Body:

     {
         "dnat_rule": {
             "floating_ip_id": "bf99c679-9f41-4dac-8513-9c9228e713e1",
             "nat_gateway_id": "cda3a125-2406-456c-a11f-598e10578541",
             "port_id": "9a469561-daac-4c94-88f5-39366e5ea193",
             "internal_service_port": 993,
             "protocol": "tcp",
             "external_service_port": 242,
             "description": "my dnat rule 01"
         }
     }

   • Example response

     {
         "dnat_rule": {
             "floating_ip_id": "bf99c679-9f41-4dac-8513-9c9228e713e1",
             "status": "PENDING_CREATE",
             "nat_gateway_id": "cda3a125-2406-456c-a11f-598e10578541",
             "admin_state_up": true,
             "port_id": "9a469561-daac-4c94-88f5-39366e5ea193",
             "internal_service_port": 993,
             "protocol": "tcp",
             "tenant_id": "abc",
             "created_at": "2017-11-15 15:44:42.595173",
             "id": "79195d50-0271-41f1-bded-4c089b2502ff",
             "external_service_port": 242,
             "floating_ip_address": "5.21.11.226",
             "description": "my dnat rule 01"
         }
     }

5. Verify that the DNAT rule is successfully created.
   • API

     URI format: GET /v2/{project_id}/dnat_rules/{dnat_rule_id}

     For details, see Querying Details About a Specified DNAT Rule.

   • Example request

     GET https://{Endpoint}/v2/27e25061336f4af590faeabeb7fcd9a3/dnat_rules/79195d50-0271-41f1-bded-4c089b2502ff

     Obtain {endpoint} from Regions and Endpoints.

   • Example response

     {
         "dnat_rule": {
             "floating_ip_id": "bf99c679-9f41-4dac-8513-9c9228e713e1",
             "status": "ACTIVE",
             "nat_gateway_id": "cda3a125-2406-456c-a11f-598e10578541",
             "admin_state_up": true,
             "port_id": "9a469561-daac-4c94-88f5-39366e5ea193",
             "internal_service_port": 993,
             "protocol": "tcp",
             "tenant_id": "abc",
             "created_at": "2017-11-15 15:44:42.595173",
             "id": "79195d50-0271-41f1-bded-4c089b2502ff",
             "external_service_port": 242,
             "floating_ip_address": "5.21.11.226",
             "description": "my dnat rule 01"
         }
     }