# Calling a private Cloud Function from On-premises
This example shows how to invoke a private Google Cloud Function from the on-prem environment via a Private Service Connect endpoint.
According to the [documentation](https://cloud.google.com/functions/docs/networking/network-settings#ingress_settings), only requests from VPC networks in the same project or VPC Service Controls perimeter are allowed to call a private Cloud Function. That's the reason why a Private Service Connect endpoint is needed in this architecture.
The Terraform script in this folder will create two projects connected via VPN: one to simulate the on-prem environment and another containing the Cloud Function and the Private Service Connect endpoint.
The "on-prem" project contains a small VM that can be used to test the accessibility to the private Cloud Function:
```bash
curl https://YOUR_REGION-YOUR_PROJECT_ID.cloudfunctions.net/YOUR_FUNCTION_NAME
```
![Cloud Function via Private Service Connect](diagram.png "High-level diagram")
## Variables
| name | description | type | required | default |
|---|---|:---:|:---:|:---:|
| [project_id](variables.tf#L44) | Project id. | string
| ✓ | |
| [ip_ranges](variables.tf#L17) | IP ranges used for the VPCs. | object({…})
| | {…}
|
| [name](variables.tf#L29) | Name used for new resources. | string
| | "cf-via-psc"
|
| [project_create](variables.tf#L35) | If non null, creates project instead of using an existing one. | object({…})
| | null
|
| [psc_endpoint](variables.tf#L49) | IP used for the Private Service Connect endpoint, it must not overlap with the hub_ip_range. | string
| | "172.16.32.1"
|
| [region](variables.tf#L55) | Region where the resources will be created. | string
| | "europe-west1"
|
## Outputs
| name | description | sensitive |
|---|---|:---:|
| [function_url](outputs.tf#L17) | URL of the Cloud Function. | |