Connectivity to services hosted in serverless environment

This page describes how you can configure Integration Connectors to connect to services hosted in serverless environments such as Cloud Run in Google Cloud.

The following image shows a private network connectivity setup from Integration Connectors to a service hosted in the Cloud Run environment in Google Cloud:

This page assumes that you are familiar with the following concepts:

Considerations

When you create a PSC service attachment, consider the following key points:

  • The PSC service attachment and the load balancer are created in different subnets within the same VPC. And specifically, the service attachment is always created in a NAT subnet.
  • Traffic from load balancer and health check probe must be sent to the same port.
  • Configure the firewall rules to facilitate the traffic flow.

    Ingress rules

    Traffic from the PSC service attachment's subnet must reach your backend service.

    Egress rules

    Egress traffic is enabled by default in a Google Cloud project, unless specific deny rules are configured.

  • All your Google Cloud components such as the PSC service attachment and the load balancer must be in the same region.

Create a PSC service attachment

In order to establish private connectivity from Integration Connectors, your service must be exposed to Integration Connectors using a PSC service attachment. A service attachment always uses a load balancer. Therefore, if your service isn't behind a load balancer, a load balancer needs to be configured.

  1. Create a load balancer. If you already have a load balancer, skip this step.

    Create an application load balancer using serverless NEG as the backend by following the instructions at Set up a regional internal Application Load Balancer with Cloud Run.

  2. Create the service attachment
    1. Create a subnet for PSC NAT. The following command creates a subnet with the name psc-nat-subnet1 and the purpose is PRIVATE_SERVICE_CONNECT. 
      gcloud compute networks subnets create psc-nat-subnet1 \
          --network=VPC_NETWORK --range=SUBNET_RANGE_1 \
          --purpose=PRIVATE_SERVICE_CONNECT
    2. Create a firewall rule to allow traffic from the PSC NAT to the load balancer. 
      gcloud compute network-firewall-policies rules create PRIORITY --firewall-policy FIREWALL_POLICY_NAME_SA \
    --direction=INGRESS  --network=VPC_NETWORK \
    --action=allow --allow=tcp:BACKEND_SERVER_PORT --src-ip-ranges=SUBNET_RANGE_1
    3. Create service attachment with explicit approval. 
      gcloud compute service-attachments create SERVICE_ATTACHMENT_NAME --producer-forwarding-rule=FORWARDING_RULE_NAME  --connection-preference=ACCEPT_MANUAL --consumer-accept-list=SERVICE_DIRECTORY_PROJECT_ID=LIMIT --nat-subnets=psc-nat-subnet1

      In this command, LIMIT is the connection limit for the project. The connection limit is the number of consumer PSC endpoints that can connect to this service. To get the SERVICE_DIRECTORY_PROJECT_ID, do the following step:

      • You can create the PSC service attachment such that it accepts requests only from the specified Google Cloud projects. However, to do this, you need the project ID of the service directory associated with your Google Cloud project. To get the project ID of the service directory, you can use the List Connections API as shown in the following example.

        Syntax

        curl -X GET \
    -H "authorization: Bearer $(gcloud auth print-access-token)" \
    -H "Content-Type: application/json" \
    "https://connectors.googleapis.com/v1/projects/CONNECTORS_PROJECT_ID/locations/-/connections"

        Replace the following:

        • CONNECTORS_PROJECT_ID: The ID of your Google Cloud project where you created your connection.

        Example

        This example gets the project ID of the service directory for the connectors-test Google Cloud project.

        curl -X GET \
    -H "authorization: Bearer $(gcloud auth print-access-token)" \
    -H "Content-Type: application/json" \
    "https://connectors.googleapis.com/v1/projects/connectors-test/locations/-/connections"

        Running this command on the terminal displays an output similar to the following:

        .....
{
  "connections": [
    {
      "name": "projects/connectors-test/locations/asia-northeast1/connections/big-query-iam-invalid-sa",
      "createTime": "2022-10-07T09:02:31.905048520Z",
      "updateTime": "2022-10-07T09:22:39.993778690Z",
      "connectorVersion": "projects/connectors-test/locations/global/providers/gcp/connectors/bigquery/versions/1",
      "status": {
        "state": "ACTIVE"
      },
      "configVariables": [
        {
          "key": "project_id",
          "stringValue": "connectors-test"
        },
        {
          "key": "dataset_id",
          "stringValue": "testDataset"
        }
      ],
      "authConfig": {},
      "serviceAccount": "564332356444-compute@developer.gserviceaccount.com",
      "serviceDirectory": "projects/abcdefghijk-tp/locations/asia-northeast1/namespaces/connectors/services/runtime",
      "nodeConfig": {
        "minNodeCount": 2,
        "maxNodeCount": 50
      }
    },
....

        In the sample output, for the connectors-test Google Cloud project, the project ID of the service directory is abcdefghijk-tp.

Create an endpoint attachment to consume the PSC service attachment

Endpoint attachment as an IP address

For instructions on how to create an endpoint attachment as an IP address, see Create an endpoint attachment as an IP address.

Endpoint attachment as a hostname

In certain cases such as TLS enabled backends, the destination requires you to use hostnames instead of private IPs to perform TLS validation. In those cases where a private DNS is used instead of an IP address for the host destination, in addition to creating an endpoint attachment as an IP address, you must also configure managed zones. For instructions on how to create an endpoint attachment as a hostname, see Create an endpoint attachment as a hostname.

Later, when you configure your connection to use the endpoint attachment, you can select this endpoint attachment.

Configure a connection to use the endpoint attachment

Now that you have created an endpoint attachment, use the endpoint attachment in your connection. When you create a new connection or update an existing connection, in the Destinations section, select Endpoint attachment as the Destination Type and select the endpoint attachment that you created from the Endpoint Attachment list.

If you created a managed zone, select Host Address as the Destination Type and use the A-record that you created while creating the managed zone.

Troubleshooting tips

Follow the guidelines listed in this section to avoid common issues: