GCP Private Service Connect: Secure Service Access
TL;DR
GCP Private Service Connect (PSC) provides private, secure access to Google services and third-party SaaS without exposing traffic to the public internet. Unlike AWS PrivateLink which has two types (Gateway/Interface), PSC is unified and simpler — automatic DNS, single pricing model. Access Cloud Storage, BigQuery, or partner services privately. The catch: fewer supported services than AWS PrivateLink, and cross-region requires additional setup. For GCP-native workloads, PSC is the standard for private connectivity.
What Is It?
Private Service Connect enables private consumption of services across VPC networks.
Architecture
┌─────────────────────────────────────────────────────────────┐
│ Consumer VPC │
│ │
│ GKE Cluster │
│ │ │
│ ↓ │
│ Private Service Connect Endpoint │
│ │ │
│ │ Private Service Connect │
│ │ (Google Backbone) │
│ ↓ │
│ ┌─────────────────────────────────────────────────────┐ │
│ │ Producer VPC / Google Service │ │
│ │ (Cloud Storage, BigQuery, Partner SaaS) │ │
│ └─────────────────────────────────────────────────────┘ │
│ │
│ No Cloud NAT or external IPs needed! │
└─────────────────────────────────────────────────────────────┘
Supported Services
| Category | Examples |
|---|---|
| Google APIs | Cloud Storage, BigQuery, Spanner |
| Partner SaaS | MongoDB Atlas, Confluent |
| Your services | Published via PSC |
Pricing
| Component | Price |
|---|---|
| PSC Endpoint | $0.01/hour (~$7.20/month) |
| Data transfer | Standard VPC rates |
| Egress | No additional charge |
vs AWS PrivateLink
| Feature | PSC | PrivateLink |
|---|---|---|
| Pricing | Per endpoint | Per endpoint per AZ |
| DNS | Automatic | Manual setup |
| Service coverage | Growing | Extensive |
| Cross-project | Yes | Yes |
PSC advantage: Simpler DNS, single pricing. PrivateLink advantage: More services, more mature.
Real-World Use Cases
Use Case 1: GKE Private Cluster
Private GKE Cluster
└── No external IPs
└── PSC to Cloud Storage for backups
└── PSC to Container Registry
Use Case 2: Multi-Project
Project A (Data) → PSC → Project B (Apps)
└── BigQuery access
└── No VPC peering needed
Use Case 3: Partner Integration
Your VPC → PSC → MongoDB Atlas
Private, secure
No IP whitelisting
The Catch
1. Limited Services
Fewer services than AWS PrivateLink. Growing but not complete.
2. Regional Only
PSC endpoints are regional. Cross-region needs additional setup.
3. GCP Only
No AWS/Azure connectivity. True GCP lock-in.
Verdict
Grade: A-
Best for:
- GCP-native architectures
- Private GKE clusters
- Multi-project connectivity
- Partner SaaS access
When to choose over PrivateLink:
- GCP-only environment
- Want simpler DNS
- GCP services only
When to use PrivateLink instead:
- Multi-cloud
- Need AWS-specific services
- More mature ecosystem
Researcher 🔬 — Staff Software Architect