Accessing VPEs from an on-prem network using Direct Link or from another VPC using Transit Gateway

For Virtual Private Endpoint (VPE) enabled services, you can access IBM Cloud resources over a private network from your on-premises location through IBM Cloud Direct Link, or from another VPC using IBM Cloud Transit Gateway. By using an endpoint gateway, traffic between your VPC and IBM Cloud services does not leave the private network.

IBM Cloud Virtual Private Endpoint (VPE) for VPC enables you to access supported IBM Cloud services remotely by using the IP addresses of your choice, which are allocated from a subnet within your VPC.

You should put VPEs in a separate, dedicated subnet that is not associated with your workloads. If you want to access a VPE from another subnet, ensure that you configure your network ACLs or security groups to allow for cross-subnet access. For example, make sure that you open the proper ports within your ACLs or security groups to allow access.

Only TCP services are supported.

Architecture

The following topology illustrates remote, direct access to a VPE in a VPC through Direct Link and Transit Gateway. The VPEs are created in a central place and custom resolvers are used to resolve the VPE.

The topology demonstrates that you can access a VPE from a remote client that is connected through Direct Link or through Transit Gateway. You must provision a custom resolver in the VPC where you created VPE gateways for the Domain Name Server (DNS) resolution. When accessing VPE from a remote client through Direct Link, you must configure DNS forwarding rules for the private endpoints that you want to access through VPE, to the custom resolver provisioned in the VPC where VPE gateways are created. When accessing VPE from a remote client through Transit Gateway, you must also provision a custom resolver in the VPC where the client is running, and configure DNS forwarding rules to the custom resolver provisioned in the VPC where VPE gateways are created.

Procedure

You cannot provision multiple VPE gateways using the same service within the VPC. For example, if you have a VPE for the Global Search service, you cannot provision a duplicate Global Search service.

Follow these steps:

Provide IBM with the IBM Cloud accounts that you want to use to enable Direct Link to VPE access.
Choose one of the following options:
- (Recommended) Create a VPE for your VPC API endpoint in the VPC that you provisioned. To do so, follow these steps:
  1. Create a custom resolver. For more information, see Working with custom resolvers.
    - For IBM domains, you must also have an on-premises DNS resolver that points to either the user's DNS (Direct Link) or the custom resolver (Transit Gateway) in your VPC. You can then connect directly to the VPE and access IBM Cloud services.
    - If accessing the VPC from another VPC, you only need a custom resolver, which forwards to the custom resolver in the VPC that has the VPE.
  2. Create a VPE. For more information, see Creating an endpoint gateway.
  3. Attach a new or existing security group (or modify the default security group) to allow inbound traffic to the VPE.
- Enable this feature within an account that has a VPC with a VPE already provisioned. To do so, you must create a custom resolver before you can access the VPE over IBM Cloud Direct Link.
  
  For IBM domains, you must have an on-premises DNS resolver that points to either the user's DNS (Direct Link) or the custom resolver (Transit Gateway) in your VPC. Then, you can connect directly to the VPE and access IBM Cloud services.
  
  For resolutions of the VPE endpoints, you must forward the DNS requests to the custom resolvers within the DNS service that is provisioned within your VPC so that it can resolve the VPE addresses.
Verify that you have access from the direct link:

You should now be able to access a VPC API endpoint from an on-prem network through your Direct Link. You can use this VPC API endpoint over IBM Cloud Direct Link to provision additional resources in your VPC, such as VPEs for other IBM Cloud services.

For example, if you want to create a VPE for IBM Cloud Identity and Access Management (IAM), you can make the following REST API call from an on-premises network by using a private VPC API endpoint to provision VPE for IAM:
```
curl -X POST "$rias_endpoint/v1/endpoint_gateways?version=$version&generation=2" -H "Authorization: $iam_token" -d '{
"name": "my-iam-endpoint-gateway",
"target": {
"crn" : "crn:v1:bluemix:public:iam-svcs:global:::endpoint:private.iam.cloud.ibm.com",
"resource_type":"provider_cloud_service"
},
"vpc": { "id": "r006-5293202a-ace4-40a1-85bf-4a0afe2831cd"},
"ips":[
{"id":"0717-a28a0592-16fb-4681-af0f-e9876519ce04"}
]
```

Accessing the VPC API private endpoint from the CLI

To access the VPC API private endpoint by using the CLI, follow these steps:

Update the core IBM Cloud CLI (1.3.0 or higher) and the VPC infrastructure service plug-in (0.8.0 or higher) to the latest versions:
```
ibmcloud update
ibmcloud plugin update vpc-infrastructure
```
If you do not have the VPC infrastructure service plug-in installed, enter the following command:
```
ibmcloud plugin install vpc-infrastructure
```
To switch to API private endpoint mode, enter the following command:
```
ibmcloud login -a private.cloud.ibm.com
```
Currently, API private endpoint mode supports only the us-south and us-east regions.

To confirm that you are accessing the private endpoint, you can print the JSON data from the API:

ibmcloud is zones --output json

The output appears similar to the following:

[
    {
        "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south/zones/us-south-1",
        "name": "us-south-1",
        "region": {
            "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south",
            "name": "us-south"
        },
        "status": "available"
    },
    {
        "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south/zones/us-south-2",
        "name": "us-south-2",
        "region": {
            "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south",
            "name": "us-south"
        },
        "status": "available"
    },
    {
        "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south/zones/us-south-3",
        "name": "us-south-3",
        "region": {
            "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south",
            "name": "us-south"
        },
        "status": "available"
    }

Accessing the VPC API private endpoint with the API

To access the VPC API private endpoint using the API, follow these steps:

Set an environment variable for the region that you want to access. For example, for us-south, enter:
```
set rias_endpoint=https://us-south.private.iaas.cloud.ibm.com
```

When the environment variable is initiated, enter the following command:

curl -s GET "$rias_endpoint/v1/regions/us-south/zones?generation=2&&version=2021-01-01" -H "Authorization:$iam_token" |jq .

The output appears similar to the following:

{
  "zones": [
    {
      "name": "us-south-1",
      "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south/zones/us-south-1",
      "region": {
        "name": "us-south",
        "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south"
      },
      "status": "available"
    },
    {
      "name": "us-south-2",
      "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south/zones/us-south-2",
      "region": {
        "name": "us-south",
        "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south"
      },
      "status": "available"
    },
    {
      "name": "us-south-3",
      "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south/zones/us-south-3",
      "region": {
        "name": "us-south",
        "href": "https://us-south.private.iaas.cloud.ibm.com/v1/regions/us-south"
      },
      "status": "available"
    }
  ]
}

Accessing the VPC API private endpoint with Terraform

To access the VPC API private endpoint using Terraform, do one of the following:

Set an environment variable for the region that you want to access. For example, for us-south, enter:
```
export IBMCLOUD_IS_NG_API_ENDPOINT=https://us-south.private.iaas.cloud.ibm.com/v1
```

Declare the provider block. For example:

provider "ibm" {
region     = "us-south"
visibility = "private"
}