feat: add keyless OpenCode Google MCP identity

README.md

@@ -68,14 +68,19 @@ No modules.
 | [google_apikeys_key.this](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/apikeys_key) | resource |
 | [google_billing_budget.project](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/billing_budget) | resource |
 | [google_iam_workload_identity_pool.github](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/iam_workload_identity_pool) | resource |
+| [google_iam_workload_identity_pool.kubernetes](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/iam_workload_identity_pool) | resource |
 | [google_iam_workload_identity_pool_provider.github](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/iam_workload_identity_pool_provider) | resource |
+| [google_iam_workload_identity_pool_provider.opencode_kubernetes](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/iam_workload_identity_pool_provider) | resource |
 | [google_kms_crypto_key.sops](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/kms_crypto_key) | resource |
 | [google_kms_key_ring.sops](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/kms_key_ring) | resource |
 | [google_project.this](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/project) | resource |
+| [google_project_iam_member.opencode_mcp](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/project_iam_member) | resource |
 | [google_project_iam_member.terraformer](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/project_iam_member) | resource |
 | [google_project_service.this](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/project_service) | resource |
+| [google_service_account.opencode_mcp](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/service_account) | resource |
 | [google_service_account.terraformer](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/service_account) | resource |
 | [google_service_account_iam_member.github_workload_identity_user](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/service_account_iam_member) | resource |
+| [google_service_account_iam_member.opencode_mcp_workload_identity_user](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/service_account_iam_member) | resource |
 | [google_storage_bucket.state](https://registry.terraform.io/providers/hashicorp/google/latest/docs/resources/storage_bucket) | resource |
 
 ## Inputs
@@ -99,6 +104,8 @@ No modules.
 | Name | Description |
 | ---- | ----------- |
 | <a name="output_github_workload_identity_provider"></a> [github\_workload\_identity\_provider](#output\_github\_workload\_identity\_provider) | GitHub Actions Workload Identity Provider resource name. |
+| <a name="output_opencode_mcp_service_account_email"></a> [opencode\_mcp\_service\_account\_email](#output\_opencode\_mcp\_service\_account\_email) | Keyless service account for the managed Google Cloud MCP server. |
+| <a name="output_opencode_mcp_workload_identity_provider"></a> [opencode\_mcp\_workload\_identity\_provider](#output\_opencode\_mcp\_workload\_identity\_provider) | WIF provider for the OpenCode Kubernetes ServiceAccount. |
 | <a name="output_project_id"></a> [project\_id](#output\_project\_id) | Created GCP project ID. |
 | <a name="output_sops_kms_resource"></a> [sops\_kms\_resource](#output\_sops\_kms\_resource) | Cloud KMS resource for SOPS gcp\_kms recipients. |
 | <a name="output_state_bucket_name"></a> [state\_bucket\_name](#output\_state\_bucket\_name) | GCS bucket to configure as the OpenTofu backend after bootstrap. |

identity.tf

@@ -14,6 +14,31 @@ resource "google_project_iam_member" "terraformer" {
   member  = "serviceAccount:${google_service_account.terraformer.email}"
 }
 
+# This service account is reserved for OpenCode's direct connection to the
+# Google-managed Cloud CLI MCP server. It has no key and can only be
+# impersonated by the named Kubernetes ServiceAccount through WIF.
+resource "google_service_account" "opencode_mcp" {
+  project      = google_project.this.project_id
+  account_id   = "opencode-mcp"
+  display_name = "OpenCode managed MCP"
+
+  depends_on = [google_project_service.this]
+}
+
+resource "google_project_iam_member" "opencode_mcp" {
+  for_each = toset([
+    "roles/browser",
+    "roles/cloudkms.viewer",
+    "roles/iam.securityReviewer",
+    "roles/mcp.toolUser",
+    "roles/serviceusage.serviceUsageViewer",
+  ])
+
+  project = google_project.this.project_id
+  role    = each.value
+  member  = "serviceAccount:${google_service_account.opencode_mcp.email}"
+}
+
 resource "google_iam_workload_identity_pool" "github" {
   project                   = google_project.this.project_id
   workload_identity_pool_id = "github"
@@ -47,3 +72,38 @@ resource "google_service_account_iam_member" "github_workload_identity_user" {
   role               = "roles/iam.workloadIdentityUser"
   member             = "principalSet://iam.googleapis.com/${google_iam_workload_identity_pool.github.name}/attribute.repository/${local.github_repository}"
 }
+
+# Kubernetes publishes the public ServiceAccount signing keys at this issuer.
+# The provider accepts only the OpenCode workload identity, preventing other
+# cluster workloads from impersonating the Google MCP service account.
+resource "google_iam_workload_identity_pool" "kubernetes" {
+  project                   = google_project.this.project_id
+  workload_identity_pool_id = "kubernetes"
+  display_name              = "k3s workloads"
+  description               = "k3s ServiceAccount identities for Make IT Work Cloud workloads."
+
+  depends_on = [google_project_service.this]
+}
+
+resource "google_iam_workload_identity_pool_provider" "opencode_kubernetes" {
+  project                            = google_project.this.project_id
+  workload_identity_pool_id          = google_iam_workload_identity_pool.kubernetes.workload_identity_pool_id
+  workload_identity_pool_provider_id = "opencode"
+  display_name                       = "OpenCode k3s workload"
+
+  attribute_mapping = {
+    "google.subject" = "assertion.sub"
+  }
+
+  attribute_condition = "assertion.sub == \"system:serviceaccount:opencode:opencode-mcp\""
+
+  oidc {
+    issuer_uri = "https://api.makeitwork.cloud"
+  }
+}
+
+resource "google_service_account_iam_member" "opencode_mcp_workload_identity_user" {
+  service_account_id = google_service_account.opencode_mcp.name
+  role               = "roles/iam.workloadIdentityUser"
+  member             = "principal://iam.googleapis.com/${google_iam_workload_identity_pool.kubernetes.name}/subject/system:serviceaccount:opencode:opencode-mcp"
+}

main.tf

@@ -4,6 +4,7 @@ locals {
   project_services = toset([
     "apikeys.googleapis.com",
     "cloudbilling.googleapis.com",
+    "cloudcli.googleapis.com",
     "cloudkms.googleapis.com",
     "cloudresourcemanager.googleapis.com",
     "generativelanguage.googleapis.com",

outputs.tf

@@ -22,3 +22,13 @@ output "github_workload_identity_provider" {
   description = "GitHub Actions Workload Identity Provider resource name."
   value       = google_iam_workload_identity_pool_provider.github.name
 }
+
+output "opencode_mcp_service_account_email" {
+  description = "Keyless service account for the managed Google Cloud MCP server."
+  value       = google_service_account.opencode_mcp.email
+}
+
+output "opencode_mcp_workload_identity_provider" {
+  description = "WIF provider for the OpenCode Kubernetes ServiceAccount."
+  value       = google_iam_workload_identity_pool_provider.opencode_kubernetes.name
+}