Unleash on Google Cloud Run
Unleash is an open-source, Apache-2.0-licensed feature-flag and toggle-management platform for progressive delivery, A/B testing, and gradual rollouts. This module deploys Unleash on Cloud Run v2 on top of the App_CloudRun foundation, which provisions and manages the shared Google Cloud infrastructure.
This guide focuses on the cloud services Unleash uses and how to explore and operate them from the Google Cloud Console and the command line. For the mechanics common to every Cloud Run application — service identity, ingress and load balancing, scaling and concurrency, CI/CD, Cloud Armor, IAP, Binary Authorization, VPC Service Controls, backups, and the deployment lifecycle — refer to the App_CloudRun foundation guide rather than repeating them here.
1. Overview
Unleash runs as a Node.js container on Cloud Run v2. The deployment wires together a focused set of Google Cloud services:
| Capability | Google Cloud service | Notes |
|---|---|---|
| Compute | Cloud Run v2 | Node.js service, 1 vCPU / 512 MiB by default, serverless autoscaling; scale-to-zero supported |
| Database | Cloud SQL for PostgreSQL 15 | Required — Unleash does not support MySQL or other engines |
| Secrets | Secret Manager | Auto-generated bootstrap admin API token (INIT_ADMIN_API_TOKENS); database password |
| Ingress | Cloud Run URL / Cloud Load Balancing | Default run.app URL; optional external HTTPS load balancer + custom domain |
Sensible defaults worth knowing up front:
- PostgreSQL 15 is mandatory. The database engine is fixed by the shared application layer; selecting any other engine breaks startup.
- Unleash is stateless. All flag, toggle, strategy, segment, and audit data lives in PostgreSQL — no object storage, NFS, or persistent volume is provisioned, and any instance can serve any request.
- No Redis or queue backend. Unleash needs no cache or queue; it scales horizontally by pointing more instances at the same database.
INIT_ADMIN_API_TOKENSis generated automatically and stored in Secret Manager. Unleash seeds this all-access (*:*) admin API token into its database at first boot so automation can call the Admin API immediately.- Scale-to-zero is enabled by default (
min_instance_count = 0,cpu_always_allocated = false). Cold starts add a few seconds to the first request after idle. Setmin_instance_count = 1if SDK clients poll on a tight interval and cold-start latency is unacceptable. DATABASE_URLis assembled at container start from the platform-injectedDB_*variables by the custom image entrypoint, which branches on the connection type (socket, loopback proxy, or private IP) and keeps TLS certificate verification on for direct private-IP connections (secure by default).- The health endpoint is
/health— a public, unauthenticated 200 endpoint. The Admin API under/api/admin/*requires a token.
2. Google Cloud Services & How to Explore Them
All commands assume PROJECT and REGION are set. Service and resource names are
reported in the deployment Outputs.
A. Cloud Run — the Unleash service
Unleash runs as a Cloud Run v2 service that autoscales by request load between the minimum and maximum instance counts. Each deployment creates an immutable revision; traffic can be split across revisions for safe rollouts.
- Console: Cloud Run → select the service for revisions, traffic, logs, and metrics.
- CLI:
gcloud run services list --project "$PROJECT" --region "$REGION"
gcloud run services describe <service-name> --project "$PROJECT" --region "$REGION"
gcloud run revisions list --service <service-name> --project "$PROJECT" --region "$REGION"
See App_CloudRun for scaling, concurrency, execution environment, and traffic splitting.
B. Cloud SQL for PostgreSQL 15
Unleash stores all application data (projects, feature flags, strategies, segments, API tokens, users, and the change/audit log) in a managed Cloud SQL for PostgreSQL 15 instance. The service connects privately through the Cloud SQL Auth Proxy; no public IP is exposed. On first deploy an initialization Job creates the application database and user, and Unleash applies its own schema migrations on startup.
- Console: SQL → select the instance for connections, backups, flags, metrics.
- CLI:
gcloud sql instances list --project "$PROJECT"
gcloud sql instances describe <instance-name> --project "$PROJECT"
gcloud sql connect <instance-name> --user=<db-user> --database=<db-name> --project "$PROJECT"
The instance name, database, user, and password secret are in the Outputs. See App_CloudRun for the connection model, backups, and password rotation.
C. Secret Manager
A bootstrap admin API token is generated automatically and stored in Secret Manager,
injected as INIT_ADMIN_API_TOKENS. The database password is managed separately by
the foundation.
- Console: Security → Secret Manager.
- CLI:
gcloud secrets list --project "$PROJECT" --filter="name~admin-token"
gcloud secrets versions access latest --secret=<secret-name> --project "$PROJECT"
# Use the token against the Admin API:
curl -s -H "Authorization: <token>" "$SERVICE_URL/api/admin/projects"
See App_CloudRun for injection and rotation details.
D. Networking & ingress
The service is reachable at its run.app URL by default, which allows the public
access SDK clients and CI systems need to reach the Unleash API. An external HTTPS
load balancer with a custom domain, Cloud CDN, and Cloud Armor can be layered on;
ingress settings and VPC egress control connectivity.
- Console: Cloud Run (service URL); Network services → Load balancing.
- CLI:
gcloud run services describe <service-name> --region "$REGION" --format='value(status.url)'
gcloud compute addresses list --project "$PROJECT"
See App_CloudRun.
E. Cloud Logging & Monitoring
Container logs flow to Cloud Logging; Cloud Run and Cloud SQL metrics flow to Cloud Monitoring, with optional uptime checks and alert policies.
- Console: Logging → Logs Explorer; Monitoring → Dashboards / Alerting.
- CLI:
gcloud run services logs read <service-name> --project "$PROJECT" --region "$REGION" --limit 50
3. Unleash Application Behaviour
- First-deploy database setup. An initialization Job runs
create-db-and-user.shusingpostgres:15-alpine. It connects through the Cloud SQL Auth Proxy and idempotently creates the application database and user and grants privileges. The job is safe to re-run; it does not create tables. - Schema migrations on start. Unleash applies its own schema migrations automatically on every startup, so upgrading the application version applies schema changes without a separate migration step. Allow generous startup headroom on the first boot against an empty database.
DATABASE_URLis composed at runtime. The custom image entrypoint assembles the connection string from the injectedDB_*variables. Verify the running revision's injected variables when debugging a connection issue:gcloud run services describe <service-name> \
--region "$REGION" --project "$PROJECT" \
--format='value(spec.template.spec.containers[0].env)'- Bootstrap admin API token.
INIT_ADMIN_API_TOKENSseeds an all-access (*:*) admin API token at first boot so CI, the Unleash CLI, and SDK back ends can call the Admin API without a UI login. Retrieve it from Secret Manager (§2C). - Default UI credentials. The admin UI ships a well-known first-run account —
admin/unleash4all. Change the password immediately after the first login. - Health path. Startup and liveness probes target
/health— a public, unauthenticated endpoint that returns 200 only when the server is initialised and connected to PostgreSQL. The Admin API under/api/admin/*requires a token, so it must never be used as a probe path. - Inspect job execution:
gcloud run jobs list --project "$PROJECT" --region "$REGION"
gcloud run jobs executions list --job <job-name> --project "$PROJECT" --region "$REGION"
4. Configuration Variables
Variables are grouped exactly as they appear on the deployment platform. Only settings specific to or notable for Unleash are listed; every other input is inherited from App_CloudRun with its standard behaviour.
Group 1 — Project & Identity
| Variable | Default | Description |
|---|---|---|
project_id | (required) | Target Google Cloud project. |
region | us-central1 | Region for the service and regional resources. |
Group 2 — Deployment Environment
| Variable | Default | Description |
|---|---|---|
tenant_deployment_id | demo | Short suffix that makes resource names unique per environment. |
support_users | [] | Emails granted project access and monitoring alerts. |
resource_labels | {} | Labels applied to all resources. |
Group 3 — Application Identity
| Variable | Default | Description |
|---|---|---|
application_name | unleash | Base name for resources. Do not change after first deploy. |
application_display_name | Unleash | Human-readable name shown in the Console. |
application_description | Unleash Analytics on Cloud Run | Service description. |
application_version | 5.7.0 | unleashorg/unleash-server image tag; latest is remapped to a pinned tag at build time. |
Group 4 — Runtime & Scaling
| Variable | Default | Description |
|---|---|---|
deploy_application | true | Set false to provision infrastructure only. |
container_image_source | custom | Cloud Build wraps unleashorg/unleash-server with the DATABASE_URL entrypoint. |
cpu_limit | 1000m | CPU per instance; 1 vCPU is sufficient for most deployments. |
memory_limit | 512Mi | Memory per instance; raise to 1Gi for heavy admin/reporting use. |
min_instance_count | 0 | 0 enables scale-to-zero; set 1 for tight SDK polling. |
max_instance_count | 3 | Unleash scales horizontally — all state is in PostgreSQL. |
cpu_always_allocated | false | Request-based billing; Unleash does no background work needing an always-on CPU. |
container_port | 4242 | Unleash listens on port 4242. |
execution_environment | gen2 | Gen2 recommended. |
timeout_seconds | 300 | Maximum request duration (0–3600 seconds). |
enable_cloudsql_volume | true | Cloud SQL Auth Proxy for socket connections. |
enable_image_mirroring | true | Mirror the built image into Artifact Registry. |
traffic_split | [] | Split traffic across revisions for staged rollouts. |
max_revisions_to_retain | 7 | How many old revisions to keep. |
Group 5 — Access & Ingress Control
| Variable | Default | Description |
|---|---|---|
ingress_settings | all | all lets SDK clients and CI reach the Unleash API. |
vpc_egress_setting | PRIVATE_RANGES_ONLY | Route only RFC 1918 traffic via VPC. |
enable_iap | false | Require Google sign-in. Blocks token-authenticated SDK traffic. |
iap_authorized_users / iap_authorized_groups | [] | Who may access through IAP. |
Group 6 — Environment Variables & Secrets
| Variable | Default | Description |
|---|---|---|
environment_variables | {} | Extra non-secret settings. DATABASE_URL is assembled at runtime — do not set it here. |
secret_environment_variables | {} | Map of env var → Secret Manager secret name. |
secret_propagation_delay | 30 | Seconds to wait after secret creation before proceeding. |
secret_rotation_period | 2592000s | Secret Manager rotation notification frequency. |
Group 7 — Backup & Restore
| Variable | Default | Description |
|---|---|---|
backup_schedule | 0 2 * * * | Automated backup cron (UTC). |
backup_retention_days | 7 | Retention; raise for production/compliance. |
enable_backup_import / backup_source / backup_file / backup_format | restore options | Restore from a backup on deploy. |
Group 8 — CI/CD & Binary Authorization
Standard App_CloudRun Cloud Build / Cloud Deploy integration — see
App_CloudRun. Key inputs: enable_cicd_trigger,
github_repository_url, github_token, enable_cloud_deploy,
enable_binary_authorization.
Group 9 — Custom SQL Scripts
enable_custom_sql_scripts, custom_sql_scripts_bucket, custom_sql_scripts_path,
custom_sql_scripts_use_root — run SQL from a GCS bucket after provisioning. See
App_CloudRun.
Group 10 — Load Balancer, CDN & Image Retention
| Variable | Default | Description |
|---|---|---|
enable_cloud_armor | false | Provision Global HTTPS LB + Cloud Armor WAF. |
admin_ip_ranges | [] | CIDR ranges exempted from WAF rules. |
application_domains | [] | Custom domain names for the HTTPS LB. |
enable_cdn | false | Enable Cloud CDN on the HTTPS LB backend. |
max_images_to_retain / delete_untagged_images / image_retention_days | (set) | Artifact Registry cleanup policy. |
Group 11 — Storage & Filesystem
| Variable | Default | Description |
|---|---|---|
create_cloud_storage | true | Create GCS buckets defined in storage_buckets. |
storage_buckets | [] | Empty — Unleash requires no file storage. |
enable_nfs | false | NFS is off; Unleash is stateless. |
gcs_volumes | [] | GCS Fuse volume mounts (requires gen2). |
manage_storage_kms_iam / enable_artifact_registry_cmek | false | CMEK options. |
Group 12 — Database Backend
| Variable | Default | Description |
|---|---|---|
database_type | POSTGRES_15 | Fixed — Unleash requires PostgreSQL. |
application_database_name | unleash | PostgreSQL database name. Immutable after first deploy. |
application_database_user | unleash | Application database user. Password auto-generated in Secret Manager. |
database_password_length | 32 | Generated password length (16–64). |
enable_auto_password_rotation / rotation_propagation_delay_sec | off | DB password rotation. |
enable_postgres_extensions / postgres_extensions | off / [] | Optional PostgreSQL extensions. |
Group 13 — Jobs & Scheduled Tasks
| Variable | Default | Description |
|---|---|---|
initialization_jobs | [] | Leave empty to use the built-in db-init job. |
cron_jobs | [] | Scheduled Cloud Scheduler + Cloud Run Jobs. |
additional_services | [] | Sidecar/helper Cloud Run services. |
Group 14 — Observability & Health
| Variable | Default | Description |
|---|---|---|
startup_probe | HTTP /health, 30s delay, 30 retries | Startup probe. Allow headroom for first-boot migrations. |
liveness_probe | HTTP /health, 30s delay | Liveness probe. |
startup_probe_config | HTTP /health | Structured Cloud Run startup probe. |
health_check_config | HTTP /health | Structured Cloud Run liveness probe. |
uptime_check_config | disabled, /health | Cloud Monitoring uptime check. |
alert_policies | [] | Metric alert policies. |
Group 16 — Redis
| Variable | Default | Description |
|---|---|---|
enable_redis | false | Unleash does not require Redis; leave disabled. |
redis_host | "" | Only used when enable_redis = true. |
redis_port | 6379 | Redis port. |
Group 22 — VPC Service Controls & Audit Logging
| Variable | Default | Description |
|---|---|---|
enable_vpc_sc | false | Enforce a VPC-SC perimeter (auto-discovers organization_id). |
vpc_cidr_ranges / vpc_sc_dry_run | (set) | Access level CIDRs / dry-run mode. |
enable_audit_logging | false | Detailed Cloud Audit Logs. |
5. Outputs
Returned on a successful deployment — the quickest way to locate and explore the running resources.
| Output | Description |
|---|---|
service_name | Cloud Run service name. |
service_url | Default run.app URL of the service. |
service_location | Region the service runs in. |
database_instance_name | Cloud SQL instance name. |
database_name / database_user | Application database name / user. |
database_password_secret | Secret Manager secret holding the DB password. |
storage_buckets | Created Cloud Storage buckets (empty for Unleash). |
container_image | Deployed image. |
cicd_enabled / github_repository_url | CI/CD status and connected repo. |
deployment_id / project_id | Naming and project identifiers. |
6. Configuration Pitfalls & Sensible Defaults
Risk: Critical (data loss / outage / security) — High (service degraded) — Medium (cost or partial degradation) — Low (minor).
Inherited plan-time validation. This module passes its configuration through the App_CloudRun foundation engine, which validates values and combinations at plan time — a read replica without its primary, IAP with no authorized identities, a
gen1runtime with NFS/GCS mounts, adatabase_typethat does not match an enabled extension, an out-of-rangebackup_retention_days. Invalid configuration fails the plan with a clear, named error before any resource is created, so most mistakes below are caught up front rather than at apply or runtime.
| Setting | Sensible value | Risk | Consequence if wrong |
|---|---|---|---|
database_type | POSTGRES_15 | Critical | Any other engine breaks Unleash startup — it only supports PostgreSQL. |
application_database_name / application_database_user | Set once | Critical | Immutable after first deploy; renaming recreates the DB/user and destroys all flag data. |
DATABASE_SSL_REJECT_UNAUTHORIZED (auto) | Keep true on private IP | Critical | Disabling certificate verification on a private-IP TCP connection weakens transport security. |
enable_backup_import | false unless restoring | Critical | Enabling without a valid backup_file fails the import job. |
startup_probe / liveness_probe path | /health | High | Pointing a probe at /api/admin/* returns 401/403 and the revision never becomes Ready. |
enable_iap | only when no SDK traffic | High | IAP blocks all unauthenticated requests, including token-authenticated SDK/CI calls to the Unleash API. |
ingress_settings | all | High | internal blocks external SDK clients and CI from reaching the Unleash API. |
INIT_ADMIN_API_TOKENS (auto) | Retrieve from Secret Manager | Medium | The seeded token grants all-access admin API rights — treat it as a secret and rotate if exposed. |
Default UI login admin / unleash4all | Change on first login | High | Leaving the default password exposes full admin control of every flag. |
min_instance_count | 0 (default) or 1 | Medium | Scale-to-zero adds a few seconds of cold-start latency to the first request after idle. |
backup_retention_days | 7 (raise for prod) | Medium | Too short for compliance retention. |
For the foundation behaviour referenced throughout — service identity, scaling and concurrency, ingress and load balancing, CI/CD, Cloud Armor, IAP, Binary Authorization, VPC-SC, backups, and image mirroring — see App_CloudRun. Unleash-specific application configuration shared with the GKE variant is described in Unleash_Common.