Service Usage

floci-gcp emulates the Service Usage API (serviceusage.googleapis.com v1) over REST JSON — the API that enables and lists a project's GCP services. It is the first thing most IaC tooling touches: Terraform's google_project_service and Pulumi's gcp.projects.Service call it before managing any other resource, and gcloud services is built on it.

The emulator is an accept-and-succeed control plane: enabling a service flips it to ENABLED (persisted, project-namespaced), disabling reverses it, and get/list echo that state. There is no real API gating or dependency resolution — services work whether or not they were "enabled".

Configuration

Variable	Default	Description
`FLOCI_GCP_SERVICES_SERVICEUSAGE_ENABLED`	`true`	Enable/disable Service Usage
`FLOCI_GCP_SERVICES_RESOURCEMANAGER_ENABLED`	`true`	Enable/disable the Cloud Resource Manager project lookup (see below)

Endpoints

Method	Path
`POST`	`/v1/projects/{project}/services/{service}:enable`
`POST`	`/v1/projects/{project}/services/{service}:disable`
`GET`	`/v1/projects/{project}/services/{service}`
`GET`	`/v1/projects/{project}/services` (`?filter=state:ENABLED\\|state:DISABLED`)
`POST`	`/v1/projects/{project}/services:batchEnable`
`GET`	`/v1/projects/{project}/services:batchGet?names=...`
`GET`	`/v1/operations/{operation}`, `/v1/operations`

enable, disable, and batchEnable return an already-completed google.longrunning.Operation (done: true) whose response carries the proto response type, so SDK operation futures resolve immediately. Disabling a service that is not enabled returns FAILED_PRECONDITION, matching real GCP.

Cloud Resource Manager companion

The Terraform/Pulumi Google providers verify a project exists via cloudresourcemanager.v1.Projects.GetProject before reading google_project_service. floci-gcp therefore serves a minimal Cloud Resource Manager v1 surface:

Method	Path
`GET`	`/v1/projects/{projectId}`

Every project ID resolves to an ACTIVE project with a stable synthetic projectNumber (the emulator's multi-tenancy is keyed by project ID; projects are never created or deleted).

Quick Start

TerraformgcloudJava

provider "google" {
  project = "my-project"

  service_usage_custom_endpoint    = "http://localhost:4588/v1/"
  resource_manager_custom_endpoint = "http://localhost:4588/v1/"
}

resource "google_project_service" "run" {
  service            = "run.googleapis.com"
  disable_on_destroy = true
}

Export a fake token first: export GOOGLE_OAUTH_ACCESS_TOKEN=fake-token.

export CLOUDSDK_AUTH_DISABLE_CREDENTIALS=true
export CLOUDSDK_API_ENDPOINT_OVERRIDES_SERVICEUSAGE=http://localhost:4588/

gcloud services enable run.googleapis.com pubsub.googleapis.com --project=my-project
gcloud services list --enabled --project=my-project
gcloud services disable run.googleapis.com --project=my-project --force

ServiceUsageClient client = ServiceUsageClient.create(
    ServiceUsageSettings.newHttpJsonBuilder()
        .setEndpoint("http://localhost:4588")
        .setCredentialsProvider(NoCredentialsProvider.create())
        .build());

client.enableServiceAsync(EnableServiceRequest.newBuilder()
        .setName("projects/my-project/services/run.googleapis.com")
        .build())
    .get();

Service service = client.getService(GetServiceRequest.newBuilder()
        .setName("projects/my-project/services/run.googleapis.com")
        .build());
// service.getState() == State.ENABLED

Scope and deviations

ListServices returns only services whose state has been tracked (enabled or later disabled) for the project. Real GCP also lists every public API in the DISABLED state; the emulator does not ship a catalog of Google APIs.
Service.config carries only the service name; real GCP includes title, quota, auth, and endpoint configuration.
disableDependentServices and checkIfServiceHasUsage are accepted and ignored — there is no dependency graph or usage tracking.
Batch limits match real GCP: 20 services per batchEnable, 30 names per batchGet, page size capped at 200.