OpenProject on GKE Autopilot

OpenProject is an open-source, GPLv3-licensed project-management and team-collaboration suite — work packages, Gantt timelines, agile boards, wikis, time tracking, and budgets. This module deploys OpenProject on GKE Autopilot on top of the App_GKE foundation, which provisions and manages the shared Google Cloud and Kubernetes infrastructure.

This guide focuses on the cloud services OpenProject uses and how to explore and operate them from the Google Cloud Console and the command line. For the mechanics that are common to every GKE application — Workload Identity, ingress, autoscaling, CI/CD, Cloud Armor, IAP, Binary Authorization, VPC Service Controls, backups, and the deployment lifecycle — refer to the App_GKE foundation guide rather than repeating them here.

---

What OpenProject costs on RAD, and how that compares

For a team of ten, OpenProject on RAD's GKE Autopilot module costs about US$150 a month with no per-user licence. GKE suits OpenProject that must stay up, scale across pods, or run beside other Kubernetes workloads. For the lowest cost, the Cloud Run module runs the same OpenProject for about US$181 a month. Figures are as at 8 October 2026; sources are listed at the end of this section.

If you only need it occasionally — studying for a certification, a demo, a seasonal business — a RAD-managed project can be deleted and restored within 30 days for a few credits, so that US$150 becomes a few dollars a month instead. See Pause it for free, below.

What you pay on RAD

	In a Google Cloud project you own	In a project RAD manages for you
Module fee, once per deployment	175 credits (US$17.50 at the top-up price)	157.5 credits (10% lower)
Build time	About 19 credits per build (RAD's average build takes about 19 minutes)	The same
Google Cloud running cost	Billed by Google to your own billing account (table below)	Metered hourly in credits; RAD publishes 111 credits a day, about 3,330 credits a month (about US$333 at the top-up price, US$266 at the Scale plan's rate)
Who owns what	You own the project and its billing; RAD deploys and updates it	RAD owns the project, with guardrails, quotas and budget alerts; you get console access, and a minimum purchased balance is held in reserve

10 credits cost US$1 on a one-off top-up, and less on a monthly plan. In a project RAD manages, the database, file server and network are shared by every application in the project, so a second application does not add a second database.

Default running cost in your own project (us-central1, Google list prices):

Resource (module default)	Per month
GKE Autopilot pod, 2x vCPU / 4 GiB	US$79.35
Cloud SQL for PostgreSQL, 1 vCPU / 3.75 GB, zonal, 10 GB SSD	US$51.02
NFS/cache file server (small VM)	US$13.43
Cloud NAT and networking	US$5
Cloud Storage (add-ons, backups)	US$1
GKE cluster management fee	shared across every GKE app in the project; $0 if this is your only cluster, else ~73
Total	about US$150, or about US$223 without the free tier

• GKE's free tier covers the management fee of one Autopilot or zonal cluster per billing account, so it applies only if this is your only such cluster. Cloud SQL costs the same in africa-south1 (Johannesburg); the pod and VM cost about 10% more there.
• GKE Autopilot does not scale to zero. At least one OpenProject pod always runs, so the cost above is the same whether or not anyone is using it; extra pods are added only under load.
• Avoid Filestore for a small deployment. The module uses a small NFS/cache VM by default. Filestore's smallest instance is 1 TiB, which costs about US$164 a month on its own.

How it compares

• OpenProject's own hosted Cloud Edition has no clean price for ten users. Every paid plan (from €5.95/user/month) requires a minimum of 25 users (openproject.org/pricing, 8 October 2026); the only plan that actually fits a ten-person team is the free Community plan — the same edition RAD deploys.
• A bare VPS sized close to OpenProject's 2 vCPU / 4 GiB footprint — Hetzner CPX22 or a DigitalOcean 2 vCPU/4 GB Droplet, both about US$24/month, or a GCP Compute Engine e2-standard-2 (2 vCPU/8 GB) at about US$49/month — is cheaper in cash than either RAD figure above.
• The difference is admin time: Cloud SQL backups and point-in-time recovery, Secret Manager, and Google Cloud monitoring are included on RAD. On a bare VPS, PostgreSQL, backups, patches and upgrades are your own job.

Pause it for free: delete a RAD-managed project, restore it when you need it

If OpenProject runs in a project RAD manages for you, you have a second option that goes well beyond scaling to zero: delete the whole project, and restore it within 30 days for close to nothing. This suits occasional use — studying for a certification, a demo environment, a seasonal business — far better than running OpenProject continuously.

• How it works. Deleting a RAD-managed project unlinks its billing first, then asks Google to delete the project. Google does not remove the project immediately: it keeps it, recoverable, for 30 days. Because billing is already unlinked, nothing is charged while it waits. Unlike deleting one module, this does not tear down Cloud SQL, any VM or the GKE cluster one by one — the whole project, and everything in it, simply stops.
• Restoring costs a handful of credits, not a rebuild. Within 30 days, the project's owner can restore it. RAD asks Google to undelete the project and reattaches its billing account, then asks you to run Update on each deployment to confirm everything came back. Because nothing was individually destroyed, that Update finds the same resources already there — it is a check, not a rebuild, and an Update never charges the module fee again. That costs a handful of credits (under US$1) for a typical 2–3-deployment chain, against the 180 credits (US$18) a full redeploy costs below.
• So a month of occasional use can cost a few dollars, not US$150. Deploy OpenProject, use it for a while, delete the project. Restore it next time you want it, confirm with Update, and delete it again when you're done. You pay only for the module fee once, the builds, and whatever time OpenProject was actually live.
• What this needs. You must own the project (not a bring-your-own one RAD only manages billing for), and you restore it yourself within the 30 days — after that, Google deletes it for good. Restoring is admitted like creating a new project: your purchased credit balance must still clear the tier's floor (100 credits for the sandbox tier most study and demo use fits). Google says most services are fully working again within 36 hours of a restore.
• One real gap: the backup bucket does not survive. OpenProject's backups are written to a bucket inside the project, and that bucket is not protected by Cloud Storage's soft-delete, so it is very likely gone as soon as you delete the project — even though the project itself is recoverable for 30 days. If you have made changes to OpenProject you want to keep, copy a backup out (to Google Drive, or a bucket outside the project) before you delete, the same as the redeploy workflow below. For a default installation with nothing irreplaceable in it, this does not matter.

Pay only while you use it, the other way: delete and redeploy

GKE Autopilot does not scale to zero between requests. The option above only applies to a RAD-managed project; in your own project, or once the 30-day window has passed, the way to stop paying is to delete the deployment and deploy it again when you need it.

• What a redeploy costs. The module fee again plus the builds: about 180 credits (US$18), because RAD recreates the project and shared services before OpenProject. Deleting saves money only once OpenProject would otherwise sit unused for about 4 days or more, both in your own project (about US$4.99 a day) and in a RAD-managed one (111 credits a day).
• Most of the running cost is usually the database and the shared file/cache VM. They stop only when nothing else in the project uses them, so deleting OpenProject while something else shares the project saves only OpenProject's own compute part.
• Keep data first. Backups are written to a bucket inside the deployment and are deleted with it, so copy the latest backup out before deleting if you want to keep it.
• RAD does not recreate a deleted deployment for you; you enter the settings again when you deploy.

Lab sessions and Managed Environments

• Lab sessions, for training. A trainer runs a session for a class. Each participant gets the app in their own Google Cloud project for 15 minutes to 24 hours, within an allowance the trainer sets. Either the trainer funds every place, or each participant pays for their own. Everything is deleted when the session ends and unused credits go back to the trainer.
• Managed Environments, for consultancies. A partner runs the app for a client from a ring-fenced wallet it funds, and settles with the client directly. If the wallet runs low, billing pauses and the data is kept, so nobody receives an unexpected charge. At the end the partner hands the project over and the deployments become the client's own.

Credits can be bought in more than 20 currencies, including XAF, XOF, NGN, GHS, KES and ZAR, by card, bank transfer or mobile money.

Sources (8 October 2026): Google Cloud list prices from the Cloud Billing Catalog API; radmodules.dev/pricing for RAD's own fees and daily-credit estimates; Delete and restore projects for the pause/restore window and what it says about Cloud Storage objects without soft delete; OpenProject pricing.

---

1. Overview

OpenProject runs as a Ruby on Rails (Puma) web workload. The deployment wires together a focused set of Google Cloud services:

Capability	Google Cloud service	Notes
Compute	GKE Autopilot	Rails/Puma pods, 2 vCPU / 4 GiB by default, horizontally autoscaled
Database	Cloud SQL for PostgreSQL 15	Required — OpenProject does not support MySQL or other engines
Attachment storage	Cloud Filestore (NFS)	Durable work-package attachment storage, mounted at /opt/openproject/storage
Secrets	Secret Manager	Auto-generated SECRET_KEY_BASE; database password
Ingress	Cloud Load Balancing	External LoadBalancer, optional custom domain + managed certificate
Background jobs	good_job (in-process, on PostgreSQL)	No Redis — the job queue lives in PostgreSQL

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.
• Cloud SQL Auth Proxy sidecar. enable_cloudsql_volume = true on GKE. The proxy listens on 127.0.0.1 and the entrypoint's loopback branch composes DATABASE_URL without SSL (the proxy terminates TLS).
• No Redis. Background jobs run through good_job with the queue in PostgreSQL (GOOD_JOB_EXECUTION_MODE = async); enable_redis is forwarded as false.
• SECRET_KEY_BASE is generated automatically and stored in Secret Manager. It must never be rotated after first boot — rotating it makes every existing session and all encrypted database columns unreadable.
• Migrations run in a db-migrate job, not on boot. The workload runs web-only (./docker/prod/web); a dedicated apply-time job runs rake db:migrate db:seed first, so pods boot fast against a migrated schema.
• Both health probes are TCP. Rails 8 Host Authorization 400s any HTTP probe whose Host header is the pod IP, so a TCP probe (Puma port-listening) is used for both startup and liveness. GKE supports a TCP liveness probe, so it stays enabled (unlike Cloud Run).
• Session affinity is ClientIP and a minimum of 1 replica is maintained (GKE has no scale-to-zero); a PodDisruptionBudget keeps pods serving through node upgrades.
• NFS-backed rollouts use the Recreate strategy to avoid two pods writing the same attachment volume during an update.
• The first login is admin / admin. OpenProject forces a password change on the first sign-in — do it immediately.

---

2. Google Cloud Services & How to Explore Them

All commands assume you have run gcloud container clusters get-credentials <cluster> --region <region> --project <project> and that PROJECT, REGION, and NAMESPACE are set. The namespace and other identifiers are reported in the deployment Outputs.

A. GKE Autopilot — the OpenProject workload

OpenProject pods are scheduled on Autopilot, which bills for the CPU/memory the pods actually request. Horizontal Pod Autoscaling sizes the deployment between the minimum and maximum replica counts.

• Console: Kubernetes Engine → Workloads → select the OpenProject workload to see pods, revisions, and events. Kubernetes Engine → Services & Ingress shows the external IP.
• CLI:

  kubectl get pods,svc,hpa -n "$NAMESPACE"
  kubectl logs -n "$NAMESPACE" deploy/<service-name> --tail=100
  kubectl describe hpa -n "$NAMESPACE"          # current vs target utilisation

See App_GKE for how Autopilot, scaling, and the workload type (Deployment vs StatefulSet) are managed.

B. Cloud SQL for PostgreSQL 15

OpenProject stores all application data (projects, work packages, wikis, users) in a managed Cloud SQL for PostgreSQL 15 instance. Pods reach it privately through the Cloud SQL Auth Proxy sidecar over the 127.0.0.1 loopback; no public IP is exposed. On first deploy the db-init job creates the database and user, and the db-migrate job runs rake db:migrate db:seed.

• Console: SQL → select the instance for connections, backups, flags, and 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 name, user, and the Secret Manager secret holding the password are all surfaced in the Outputs. For the connection model, automated backups, and password rotation, see App_GKE.

C. Cloud Filestore (NFS attachment storage)

Work-package attachments are stored on a Cloud Filestore NFS share mounted at /opt/openproject/storage (enable_nfs = true by default); the module points OpenProject at it by setting OPENPROJECT_ATTACHMENTS__STORAGE__PATH to nfs_mount_path whenever NFS is enabled. This keeps attachments durable and shared across pods.

• Console: Filestore → Instances.
• CLI:

  gcloud filestore instances list --project "$PROJECT"
  kubectl get pvc,pv -n "$NAMESPACE"

See App_GKE for CMEK options and GCS Fuse mounts.

D. Secret Manager

One cryptographic secret is generated automatically and stored in Secret Manager: SECRET_KEY_BASE (Rails session/cookie signing and encrypted-column key derivation). The database password is managed separately by the foundation.

• Console: Security → Secret Manager.
• CLI:

  gcloud secrets list --project "$PROJECT" --filter="name~secret-key-base"
  gcloud secrets versions access latest --secret=<secret-name> --project "$PROJECT"

The database password secret name is in the Outputs. See App_GKE for the Secret Store CSI integration and rotation.

E. Networking & ingress

By default the workload is exposed through an external Cloud Load Balancing IP (service_type = LoadBalancer). A custom domain with a Google-managed certificate can be enabled, and a static IP can be reserved so the address survives redeploys. OpenProject builds absolute URLs from OPENPROJECT_HOST__NAME and OPENPROJECT_HTTPS, where OPENPROJECT_HTTPS is not hardcoded on GKE — main.tf sets https_enabled = var.enable_custom_domain, so it is only true once a custom domain + managed certificate is configured. With no custom domain, the raw LoadBalancer IP is plain HTTP only; forcing HTTPS in that state would force-redirect every request to an https:// address that never responds (a silent, total outage). This is the opposite of OpenProject_CloudRun, which always passes https_enabled = true because a Cloud Run *.run.app URL is always HTTPS.

• Console: Network services → Load balancing; VPC network → IP addresses.
• CLI:

  kubectl get ingress,svc -n "$NAMESPACE"
  gcloud compute addresses list --project "$PROJECT"

See App_GKE for custom domains, Cloud CDN, and static IP details.

F. Cloud Logging & Monitoring

Pod stdout/stderr flow to Cloud Logging; GKE and Cloud SQL metrics flow to Cloud Monitoring. Optional uptime checks and alert policies are available.

• Console: Logging → Logs Explorer; Monitoring → Dashboards / Alerting.
• CLI:

  gcloud logging read 'resource.type="k8s_container" AND resource.labels.namespace_name="'"$NAMESPACE"'"' \
    --project "$PROJECT" --limit 50

---

3. OpenProject Application Behaviour

• Two-phase first-deploy database setup. The db-init job (postgres:15-alpine) creates the role and database; the db-migrate job then runs the app image with rake db:migrate db:seed. The migrate job drops any partial tables from an interrupted prior attempt (DROP OWNED BY CURRENT_USER CASCADE) before migrating, and creates the pg_trgm extension needed by OpenProject's trigram indexes.
• Migrations do not run on boot. The workload runs web-only (./docker/prod/web), which skips the all-in-one seeder. Rails (production) refuses to boot Puma while migrations are pending, so if db-migrate fails the apply fails loudly on the pending-migration guard — there is no silent empty-DB ship.
• SECRET_KEY_BASE is immutable after first boot. It is generated once and stored in Secret Manager. Changing it makes existing sessions and all encrypted columns unreadable. Only rotate during a planned maintenance window.
• Background jobs run in-process. good_job runs its worker and cron inside each pod (GOOD_JOB_EXECUTION_MODE = async) with the queue on PostgreSQL — no Redis.
• Host Authorization gates health probes. Rails 8 returns 400 Invalid host_name to any request whose Host header is not OPENPROJECT_HOST__NAME, including the kubelet's HTTP health probes (which use the pod IP). Both the startup and liveness probes are therefore TCP; the readiness probe hits /health_checks/default.
• First login is admin / admin. Seeded by rake db:seed. OpenProject forces a password change on first sign-in.
• Inspect job execution:

  kubectl get jobs -n "$NAMESPACE"
  kubectl logs -n "$NAMESPACE" job/<job-name>

---

4. Configuration Variables

Variables are grouped exactly as they appear on the deployment platform. Only settings specific to or notable for OpenProject are listed; every other input is inherited from App_GKE with its standard behaviour and defaults.

Group 1 — Project & Identity

Variable	Default	Description
project_id	(required)	Target Google Cloud project.
region	us-central1	Region for the workload and regional resources.

Group 2 — Deployment Environment

Variable	Default	Description
tenant_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 for cost/ownership tracking.

Group 3 — Application Identity

Variable	Default	Description
application_name	openproject	Base name for resources. Do not change after first deploy.
display_name	OpenProject	Human-readable name shown in the Console.
application_version	latest	OpenProject image tag (OPENPROJECT_VERSION). latest is pinned to the stable major 16; pin explicitly in production.

Group 4 — Runtime & Scaling

Variable	Default	Description
deploy_application	true	Set false to provision infrastructure only.
min_instance_count	1	Minimum replicas (GKE has no scale-to-zero).
max_instance_count	5	Maximum replicas (HPA upper bound).
container_port	8080	Puma's own default bind port; the module runs ./docker/prod/web (Puma directly), bypassing the all-in-one image's Apache proxy on port 80.
container_resources	2000m / 4Gi	CPU/memory limits and requests. Rails needs headroom for migrations and workers.
enable_cloudsql_volume	true	Cloud SQL Auth Proxy sidecar (loopback connection).
timeout_seconds	300	Maximum request duration (0–3600 seconds).
enable_image_mirroring	true	Mirror the OpenProject image into Artifact Registry before deployment.

Group 5 — Environment Variables & Secrets

Variable	Default	Description
environment_variables	{}	Extra non-secret settings (OPENPROJECT_* overrides). Do not set SECRET_KEY_BASE or DATABASE_URL 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 6 — GKE Backend & Cluster

Variable	Default	Description
service_type	LoadBalancer	How the Kubernetes Service is exposed.
workload_type	null (Deployment)	Deployment (default) or StatefulSet.
session_affinity	ClientIP	Sticky routing for UI sessions.
network_tags	["nfsserver"]	Node/pod network tags; nfsserver is required when enable_nfs = true.
termination_grace_period_seconds	60	Seconds to wait after SIGTERM before SIGKILL.
enable_network_segmentation	false	Create Kubernetes NetworkPolicy resources.

Group 7 — StatefulSet

Variable	Default	Description
stateful_pvc_enabled	null	Enable PVC templates. Not required — attachments use NFS.
stateful_pvc_size	10Gi	Per-pod PVC storage size.
stateful_pvc_mount_path	/data	Container mount path for the PVC.
stateful_pvc_storage_class	standard-rwo	Kubernetes StorageClass for PVCs.

Group 9 — Reliability Policies

Variable	Default	Description
enable_pod_disruption_budget	true	Protect availability during node upgrades.
pdb_min_available	1	Minimum pods available during voluntary disruptions.
enable_resource_quota	false	Enforce a namespace ResourceQuota.
quota_memory_requests / quota_memory_limits	(set)	Namespace memory quota — must use binary units (4Gi, 8192Mi).

Group 10 — Observability & Health

Variable	Default	Description
startup_probe	TCP, 30s delay, 30 × 15s window	TCP because Rails Host Authorization 400s HTTP probes; checks Puma is listening.
liveness_probe	TCP, 90s delay	TCP so a healthy Puma stays alive (GKE supports TCP liveness).
startup_probe_config	(set)	App_GKE-level infrastructure probe.
uptime_check_config	disabled	Optional Cloud Monitoring uptime check.
alert_policies	[]	Optional metric alert policies.

Group 11 — Jobs & Scheduled Tasks

Variable	Default	Description
initialization_jobs	[]	Leave empty to use the built-in db-init + db-migrate jobs.
cron_jobs	[]	Scheduled Kubernetes CronJobs.
additional_services	[]	Sidecar or helper services deployed alongside OpenProject.

Group 12 — CI/CD & GitHub Integration

Standard App_GKE Cloud Build / Cloud Deploy integration — see App_GKE. Key inputs: enable_cicd_trigger, github_repository_url, github_token, enable_cloud_deploy.

Group 13 — Filesystem (NFS)

Variable	Default	Description
enable_nfs	true	Cloud Filestore for durable attachment storage.
nfs_mount_path	/opt/openproject/storage	OpenProject attachment path inside the container.

Group 14 — Cloud Storage & Artifact Registry

Variable	Default	Description
create_cloud_storage	true	Create GCS buckets defined in storage_buckets.
storage_buckets	[{ name_suffix = "data" }]	One data bucket is declared by default; extend the list if you need more.
gcs_volumes	[]	GCS Fuse volume mounts via the CSI driver.
manage_storage_kms_iam / enable_artifact_registry_cmek	false	CMEK options.
max_images_to_retain	7	Maximum recent Artifact Registry images to keep.
delete_untagged_images	true	Automatically delete untagged images.
image_retention_days	30	Days after which images are eligible for deletion.

Group 16 — Database Backend

Variable	Default	Description
application_database_name	openproject	PostgreSQL database name. Immutable after first deploy.
application_database_user	openproject	Application database user. Immutable after first deploy.
database_password_length	32	Generated password length (16–64).
enable_auto_password_rotation	false	Zero-downtime DB password rotation.
rotation_propagation_delay_sec	90	Seconds to wait after rotation before rolling-restarting pods.

Group 17 — Backup & Maintenance

Variable	Default	Description
backup_schedule	0 2 * * *	Automated backup cron (UTC).
backup_retention_days	7	Retention; raise to 30–90 for production/compliance.
enable_backup_import / backup_source / backup_uri / backup_format	restore options	Restore from a backup on deploy.

Group 19 — Custom Domain, Static IP & Networking

Variable	Default	Description
enable_custom_domain	true	Provision Ingress for custom hostnames + managed certificate (a Gateway with a static IP is provisioned automatically).
application_domains	[]	Hostnames to serve.
reserve_static_ip	true	Stable external IP across redeploys.

Group 20 — Identity-Aware Proxy (IAP)

Variable	Default	Description
enable_iap	false	Require Google sign-in in front of OpenProject.
iap_authorized_users / iap_authorized_groups	[]	Who may access.
iap_oauth_client_id / iap_oauth_client_secret	""	Required when IAP is enabled (sensitive).

Group 21 — Cloud Armor

Variable	Default	Description
enable_cloud_armor	false	Attach a Cloud Armor (WAF) policy to the Ingress backend.
admin_ip_ranges	[]	CIDRs allowed privileged access.
cloud_armor_policy_name	default-waf-policy	Policy name.
enable_cdn	false	Enable Cloud CDN on the GKE Ingress backend.

Group 22 — VPC Service Controls & Audit Logging

Variable	Default	Description
enable_vpc_sc	false	Enforce a VPC-SC perimeter (requires 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

These values are returned on a successful deployment and are the quickest way to locate and explore the running resources.

Output	Description
service_name	Kubernetes Service name.
namespace	Namespace the workload runs in.
service_cluster_ip	In-cluster ClusterIP.
stage_service_cluster_ips	Map of ClusterIPs for stage-specific services.
service_external_ip	External LoadBalancer IP (when a static IP is reserved).
service_url	URL to reach OpenProject.
database_instance_name	Cloud SQL instance name.
database_name	Application database name.
database_user	Application database user.
database_password_secret	Secret Manager secret holding the DB password.
database_host / database_port	DB endpoint (127.0.0.1 via the Auth Proxy) / port.
storage_buckets	Created Cloud Storage buckets.
network_name / network_exists / regions	VPC network, presence, available regions.
container_image / container_registry	Deployed image and Artifact Registry repo.
monitoring_enabled / monitoring_notification_channels	Monitoring status and channels.
initialization_jobs / db_import_job	Names of the setup (db-init, db-migrate) and (optional) import jobs.
deployment_id / tenant_id / resource_prefix	Naming identifiers.
project_id / project_number	Project identifiers.
cicd_enabled / cicd_configuration	CI/CD status and details (repo, trigger, registry).
github_repository_url / github_repository_owner / github_repository_name	CI/CD GitHub details.
artifact_registry_repository / cloudbuild_trigger_name / cloudbuild_trigger_id	Registry and build trigger.
kubernetes_ready	Whether the cluster/workload is ready.
vpc_sc_enabled / vpc_sc_perimeter_name / vpc_sc_dry_run_mode	VPC-SC status.
audit_logging_enabled / artifact_registry_cmek_enabled	Audit logging and CMEK status.

---

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_GKE foundation engine, which validates values and combinations at plan time — a read replica without its primary, IAP with no authorized identities, a Deployment workload with stateful_pvc_enabled = true, a bare-integer quota_memory_*, an out-of-range backup_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
SECRET_KEY_BASE (auto-generated)	Never rotate after first boot	Critical	Rotating it makes every existing session and all encrypted database columns unreadable.
application_database_name / application_database_user	Set once	Critical	Immutable after first deploy; renaming recreates the DB/user and destroys all data.
enable_nfs	true	Critical	Disabling it puts attachments on ephemeral pod storage — they are lost when a pod is rescheduled.
enable_backup_import	false unless restoring	Critical	Enabling without a valid backup_uri fails the import job.
startup_probe.type / liveness_probe.type	TCP	High	An HTTP probe hits Rails Host Authorization (400 Invalid host_name, Host = pod IP) and never passes — a healthy pod never becomes Ready, or a TCP-healthy pod restart-loops.
enable_cloudsql_volume	true on GKE	High	The Auth Proxy sidecar provides the loopback PostgreSQL connection; disabling it is blocked by a plan-time validation guard.
memory_limit (via container_resources)	4Gi	High	Migrations and in-process workers OOM below ~2 GiB.
min_instance_count	1	High	GKE requires min ≥ 1; the validation guard rejects invalid values.
session_affinity	ClientIP	Medium	Without stickiness, UI sessions may route to different pods between requests.
quota_memory_requests / _limits	binary units (4Gi, 8192Mi)	Critical	Bare integers are bytes and block all pod scheduling in the namespace.
enable_pod_disruption_budget	true	Medium	Disabling allows GKE to evict all pods simultaneously during maintenance — with NFS Recreate, this drops the service.
application_version	Pin a major (16)	Medium	latest has no image tag on Docker Hub; the module pins it to 16. Pin explicitly to control upgrades.
backup_retention_days	7 (raise for prod)	Medium	Too short for compliance retention.

---

For the foundation behaviour referenced throughout — IAM and Workload Identity, autoscaling, ingress and certificates, CI/CD, Cloud Armor, IAP, Binary Authorization, VPC-SC, backups, and image mirroring — see App_GKE. OpenProject-specific application configuration shared with the Cloud Run variant is described in OpenProject_Common.

Related guides

• Hands-on lab: OpenProject on GKE Autopilot — deploy it step by step, with the console screens and commands at each stage.
• OpenProject on Google Cloud Run — the same application on Cloud Run, for when you need the other deployment target.
• OpenProject Common — Shared Application Configuration — the configuration shared by both deployment targets.