terraform-gcp-vpn

Production-ready WireGuard VPN on Google Cloud, powered by Terraform. Launch Firezone remote access plus optional site-to-site IPsec in minutes.

Core capabilities

• Firezone + WireGuard remote access with Google OAuth ready to configure.
• Classic Cloud VPN tunnels for partner connectivity alongside remote users.
• Hardened defaults: shielded VM, OS Login via IAP, explicit firewall policy, optional CMEK.
• Runtime secrets pulled from Secret Manager; no credentials stored in terraform state.
• Optional auto start/stop scheduling to park non-production environments.

What's included

Component	Description
modules/network	Shared VPC, subnets, Cloud NAT, static IPs.
modules/compute	Firezone VM with shielded images and CMEK-ready disks.
modules/security	Firewall rules, IAM bindings, OS Login settings.
modules/load-balancer	Regional network load balancer fronting WireGuard.
modules/vpn-gateway	Classic VPN gateway + tunnels for site-to-site IPsec.
modules/scheduler	Cloud Scheduler + Cloud Functions for start/stop automation.

Architecture at a glance

flowchart LR
  %% External connectivity
  subgraph External["External connectivity"]
    RemoteUsers["Remote users<br/>(WireGuard)"]
    PartnerNetworks["Partner networks<br/>(IPsec)"]
    PublicInternet["Public internet"]
  end

  %% Core platform
  subgraph Core["Core platform"]
    NLB["Network Load Balancer"]
    FirezoneVM["Firezone gateway VM"]
    VPC["Shared VPC network"]
    CloudVPN["Cloud VPN gateway"]
    CloudNAT["Cloud NAT"]
  end

  %% Supporting services
  subgraph Support["Supporting services"]
    GoogleWorkspace["Google Workspace SSO"]
    SecretManager["Secret Manager<br/>(WireGuard + IPsec secrets)"]
    Scheduler["Cloud Scheduler + Functions<br/>(optional)"]
  end

  %% Primary flows
  RemoteUsers -->|WireGuard| NLB --> FirezoneVM --> VPC
  PartnerNetworks -->|IPsec| CloudVPN --> VPC
  VPC --> CloudNAT --> PublicInternet

  %% Integrations
  FirezoneVM -->|OIDC authentication| GoogleWorkspace
  SecretManager -->|PSKs & admin creds| FirezoneVM
  Scheduler -.->|Start / stop VM| FirezoneVM

  %% Styling
  classDef primary fill:#1a73e8,stroke:#174ea6,color:#ffffff;
  classDef external fill:#f8f9fa,stroke:#5f6368,color:#202124;
  classDef support fill:#34a853,stroke:#0c8040,color:#ffffff;

  class NLB,FirezoneVM,VPC,CloudVPN,CloudNAT primary;
  class RemoteUsers,PartnerNetworks,PublicInternet external;
  class GoogleWorkspace,SecretManager,Scheduler support;

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Quick start

Prerequisites

• Terraform ≥ 1.6.0.
• Google Cloud project with billing enabled and gcloud authenticated.
• Service account (or ADC) with permissions for compute, networking, Secret Manager.
• Domain + SSL cert for the Firezone dashboard (optional but recommended).

Deploy in three steps

git clone https://github.com/dieguezz/terraform-gcp-vpn.git
cd terraform-gcp-vpn
cp terraform.tfvars.example terraform.tfvars
# update terraform.tfvars with your project settings
terraform init
terraform apply

Configuration essentials

Variable	What it controls	Default
project_id	Target GCP project	n/a
region	Primary region for resources	europe-southwest1
firezone_domain	Public hostname for Firezone	n/a
enable_site_to_site_vpn	Toggle Classic VPN gateway + tunnels	false
enable_scheduling	Enable auto start/stop via Cloud Scheduler	false

See terraform.tfvars.example for the full catalog of inputs.

Secure by default

• Private VM with Identity-Aware Proxy and OS Login; no public SSH.
• Optional Customer-Managed Encryption Keys for disks and bucket assets.
• Strict firewall rules and egress allow-list support.
• Secrets retrieved at runtime from Google Secret Manager only.

Operations quick links

• Makefile targets for status checks (make instance-status, make vpn-tunnel-status PARTNER=<name>, etc.).
• scripts/site-to-site/ templates to verify each partner tunnel.
• docs/incident-response.md runbook for on-call playbooks and alert testing.
• modules/scheduler/ README for enabling cost-saving automation.
• SUPPORT.md for commercial support and contact channels.

Next steps

• Customize branding and OAuth in Firezone once the stack is live.
• Duplicate the modules/vpn-gateway example to onboard partners quickly.
• Add observability dashboards and configure remote state backend as tracked in TODO.md.

Contributing & licensing

We welcome issues and PRs—please review CONTRIBUTING.md beforehand. Licensed under the GPL v3 license.