Private Access for GCP Services in VPC Networks

Question

Pulumi · Accepted Answer

When you want to enable Private Access for Google Cloud Platform (GCP) services in a VPC network, you essentially allow your virtual machines and other resources within your VPC to communicate with Google services without exposing the traffic to the public internet. This ensures that your data remains within Google's network, enhances security, and can also reduce latency.

In GCP, to set up Private Access for services, you need to configure Private Google Access and set up a private connection using a Service Networking API which involves creating a private VPC Connection. The private connection uses allocated IP address ranges within your VPC to ensure that traffic between your VPC and Google services remains internal.

Here's a step-by-step guide on how to set this up using Pulumi in Python:

1. **Create a VPC Network**: Define a Virtual Private Cloud (VPC) where your private resources will reside.
2. **Allocate IP Ranges**: Set up IP ranges reserved for your VPC. These IP ranges should not overlap with other networks.
3. **Establish a Service Networking Connection**: Create a connection using the Service Networking API to utilize Private Google Access.

The following Python program using Pulumi will configure Private Access for GCP services in a VPC network by creating these resources.

```python
import pulumi
import pulumi_gcp as gcp

# Step 1: Create a VPC Network
# This is the network where your services or VM instances will reside.
vpc_network = gcp.compute.Network(
    "private-vpc-network",
    auto_create_subnetworks=False # Disabling auto-creation of subnetworks because we want to control the subnets creation.
)

# Step 2: Allocate IP Ranges
# Reserve IP range for the services. For example, '10.8.0.0/16'
# This range represents the IP space from which private IP addresses for service endpoints will be allocated.
# The IP range must not conflict with any existing subnets or IP ranges.
reserved_range = gcp.servicenetworking.Connection(
    "private-vpc-connection",
    network=vpc_network.self_link,
    service="servicenetworking.googleapis.com", # Specify the Service Networking service
    reserved_peering_ranges=[vpc_network.name] # Use the allocated IP range here
)

# As we set up the Service Networking connection to enable Private Google access,
# VM instances in the VPC network can now reach Google services without going through the public internet.

# Optionally, you can export the URL of a resource or other output values that you want to easily access.
pulumi.export('vpc_network_name', vpc_network.name)
pulumi.export('reserved_range_name', reserved_range.name)
```

Let's break down what each step in the code is doing:

- **Compute Network**: First, we create a new VPC network `private-vpc-network` by using `gcp.compute.Network`. This network acts as a container for your cloud resources and services. The `auto_create_subnetworks` parameter is set to `False` because we want to have control over the subnetworks and ranges that are created inside this VPC.

- **Service Networking Connection**: Next, we create a `gcp.servicenetworking.Connection` named `private-vpc-connection`, which sets up a peering connection between Google's managed services and our VPC network. For the `reserved_peering_ranges`, we're passing the name of the VPC network because it's assumed we have already allocated an IP range which will be reserved exclusively for the connection.

The `pulumi.export` lines at the end of the program output the names of the created resources, which you can then use to reference these in the Pulumi CLI or in the Pulumi Console.

By running this Pulumi program with the appropriate credentials set up for GCP, the defined resources will be created in your GCP project, and private access will be configured for the services within the specified VPC network.