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floci-gcp

floci-gcp

Light, fluffy, and always free: GCP Local Emulator

floci-gcp is a fast, free, and open-source local GCP emulator built for developers who need reliable GCP services in development and CI without cost, complexity, or account setup.

Supported Services

Service Protocol Notable features
Cloud Storage (GCS) gRPC v2 + REST XML + REST JSON Buckets, objects, streaming and resumable upload, compose, rewrite, move, soft delete and restore, HMAC keys, decompressive transcoding, ACLs, bucket IAM, conditional requests, versioning, pre-signed URLs
Pub/Sub gRPC + REST Topics, subscriptions, publish, pull, streaming pull, push delivery, snapshots, seek, subscription filters
Firestore gRPC Documents, collections, queries, field transforms, aggregation, transactions, real-time listeners
Datastore gRPC + HTTP/protobuf Entity operations and structured queries over both transports; GQL queries and COUNT aggregation over HTTP/protobuf; transaction RPCs with limited semantics
Secret Manager gRPC + REST Secrets, versions, access, disable/enable/destroy, IAM bindings
Cloud Logging gRPC + REST Structured log ingestion (WriteLogEntries), read-back (ListLogEntries) with filter subset, ListLogs, DeleteLog
Cloud KMS gRPC + REST Key rings, crypto keys, versions, symmetric encrypt/decrypt, asymmetric sign/decrypt, GenerateRandomBytes
IAM REST Service accounts, RSA-2048 keys, policy bindings, SignBlob (V4 signed URLs)
Security Token Service (STS) REST OAuth 2.0 token exchange for GCS Credential Access Boundaries
Managed Kafka REST Clusters, topics, consumer groups (Redpanda-backed or mock mode)
Cloud Run REST Services and revisions, Jobs with executions and tasks, Worker Pools with revisions, Instances with :start/:stop; IAM policy operations, LRO polling; Docker-backed invocation, job runs, worker replicas and instances on by default (mock flag for control plane only)
Cloud Functions REST Function create/get/list/delete, upload URL generation, LRO polling; control plane only
Cloud SQL (PostgreSQL, MySQL) REST Instance lifecycle, LRO polling; Docker-backed PostgreSQL and MySQL data planes on by default (mock flag for control plane only)
Cloud Tasks gRPC Queues (rate limits, retry, pause/resume/purge), tasks (HTTP/App Engine targets), RunTask; control plane only
Cloud Scheduler gRPC + REST Cron jobs (Pub/Sub, HTTP, App Engine targets), Pause/Resume/RunJob, unix-cron + time zones; background dispatcher fires due jobs
Cloud Monitoring gRPC + REST Metric descriptors, monitored resource descriptors, time series write (CreateTimeSeries) and read (ListTimeSeries)
GKE (Kubernetes Engine) REST Cluster and operation APIs (container.googleapis.com v1); real k3s clusters via Docker or mock mode
BigQuery REST Datasets, tables, insertAll/tabledata.list, GoogleSQL query jobs on a DuckDB engine
Service Usage REST Enable/disable/list project services; backs Terraform google_project_service
Firebase Auth (Identity Platform) REST Identity Toolkit v1 sign-up/sign-in, emulator JWTs, admin user CRUD
Eventarc REST Trigger CRUD; delivers CloudEvents from Pub/Sub and GCS events to Cloud Run and HTTP endpoints
IAM Credentials REST generateAccessToken for service-account impersonation (shape-only stub tokens)
Resource Manager REST projects.get and project IAM policy mixins for provider project lookups

Why floci-gcp?

No account required. No auth tokens, no sign-ups, no telemetry. Pull the image and start building.

Single API port. All emulated GCP API endpoints, both gRPC and REST, use port 4588 via ALPN negotiation. Docker-backed data planes expose separate generated endpoints when their native protocols require them.

No feature gates. Every feature is available to everyone: no community-edition restrictions.

No CI restrictions. Run in your CI pipeline with zero limitations. No credits, no quotas, no paid tiers.

Truly open source. MIT licensed. Fork it, extend it, embed it.

Quick Start

docker-compose.yml
services:
  floci-gcp:
    image: floci/floci-gcp:latest
    ports:
      - "4588:4588"
    volumes:
      - ./data:/app/data
      # Enables Docker-backed services (Cloud Run, Cloud SQL, Kafka, GKE)
      - /var/run/docker.sock:/var/run/docker.sock
    environment:
      FLOCI_GCP_HOSTNAME: floci-gcp
      FLOCI_GCP_BASE_URL: http://floci-gcp:4588
      # Keep state across restarts in the mounted ./data volume
      FLOCI_GCP_STORAGE_MODE: hybrid

docker compose up -d

Point your GCP SDKs at the emulator:

export PUBSUB_EMULATOR_HOST=localhost:4588
export FIRESTORE_EMULATOR_HOST=localhost:4588
export DATASTORE_EMULATOR_HOST=localhost:4588
export STORAGE_EMULATOR_HOST=http://localhost:4588
export SECRET_MANAGER_EMULATOR_HOST=localhost:4588
export GOOGLE_CLOUD_PROJECT=floci-local

All emulated GCP APIs are immediately available at http://localhost:4588. Credentials are not cryptographically validated. The exception is a Floci-issued downscoped token, whose GCS requests are evaluated against its Credential Access Boundary (CAB).

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