Vikunja on GKE Autopilot

Vikunja is an open-source, self-hosted to-do and project management application — lists, kanban boards, gantt charts, calendars, reminders, and team sharing via a REST API and web UI. This module deploys Vikunja 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 Vikunja 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.

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What Vikunja costs on RAD, and how that compares

Running Vikunja on GKE Autopilot in your own Google Cloud project costs about US$91.31/month in Google Cloud charges (about US$164.31 if this isn't your only Autopilot cluster), on top of the same one-off 75-credit RAD module fee (US$7.50) as the Cloud Run module — this variant runs no shared NFS volume, so its fee did not need to be higher, and its running cost is lower than Cloud Run's alwaysOn figure. GKE Autopilot suits Vikunja that must run beside other Kubernetes workloads; for the lowest cost, see the Cloud Run guide instead. In a RAD-managed project the module fee drops to 67.5 credits (10% lower) — see Pause it for free below.

What you pay on RAD

	Own project	RAD-managed project
Module fee (one-off)	75 credits	67.5 credits (10% lower)
Build time	~3-6 credits per build, either way	~3-6 credits per build, either way
Google Cloud running cost	US$91.31/month, billed by Google at list price	~86 credits/day (about 2580/month, US$258 at the top-up price), metered at list price plus RAD's margin

10 credits cost US$1 on a one-off top-up, and less on a monthly plan.

Default running cost in your own project

Resource (module default)	Per month
GKE Autopilot pod, 1x vCPU / 0.5 GiB	US$34.29
Cloud SQL for PostgreSQL, 1 vCPU / 3.75 GB, zonal, 10 GB SSD	US$51.02
Cloud NAT and networking	US$5
Cloud Storage (add-ons, backups)	US$1
Total	US$91.31

The GKE cluster management fee is excluded from the total above because it is shared across every GKE app in the project — $0 if this is the only one, otherwise roughly $73/month split across however many you run.

How it compares

• Vikunja's own hosted cloud charges per user: Personal is €4/month, Family €10/month (up to 5 users), and Organization €5/month per user — verified on Vikunja's pricing page, 8 October 2026. RAD's own-project running cost here (~US$91/month) suits a team already past Family-plan size, run in infrastructure you control.
• A self-managed VPS comparison, sized to Vikunja's 1 vCPU / 0.5 GiB default: a Hetzner CPX11 or DigitalOcean 1 vCPU/2GB Droplet runs about $6-12/month — plus your own time for backups and patching, and no Kubernetes control plane to run.
• This GKE variant is actually cheaper than the Cloud Run module here (no NFS volume, and the pod itself costs less than Cloud Run's alwaysOn pricing for the same shape) — one of the few cases in this catalogue where GKE is not the more expensive option.

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

This is the headline advantage of a RAD-managed project, and it costs nothing while paused. Deleting a RAD-managed project unlinks its billing first, then asks Google to delete the project outright — Google's own 30-day recoverable soft delete. Unlike deleting one module, this does not tear down Cloud SQL, any VM, or the compute resource one by one: the whole project simply stops, and nothing is charged while it waits, because billing is already unlinked.

Restoring, within 30 days and only by the project's owner, 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. This costs only a handful of credits (under US$1) in total for a typical 2-3-deployment chain.

What this needs: you must own the project (not one RAD only manages billing for), you must restore it yourself within 30 days — after that Google deletes it for good — and restoring is admitted like creating a new project, so your purchased credit balance must still clear the tier's floor (100 credits for the sandbox tier most study/demo use fits). Google says most services are fully working again within 36 hours of a restore.

One real gap: nightly backups are written to a bucket inside the project, and that bucket has Cloud Storage's soft-delete explicitly turned off, 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've customised Vikunja and want to keep that work, copy a backup out (to Google Drive, or a bucket outside the project) before deleting. For a default install with nothing irreplaceable in it, this does not matter.

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

In your own project, or once 30 days have passed on a RAD-managed one, there is no free pause — deleting removes the resources for good, and bringing Vikunja back means redeploying from scratch. That costs about 78-81 credits in your own project, or about 70.5-73.5 credits in a RAD-managed one.

Deleting only saves money once Vikunja would otherwise sit unused long enough to clear that redeploy cost against its own running cost — about 3 days or more in your own project (about US$3.04 a day), or about 1 days or more in a RAD-managed one (86 credits a day).

Keep data first: nightly backups go 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.

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 Billing Catalog API list prices; radmodules.dev/pricing for RAD's own fees and daily-credit estimates; Google's project delete/restore documentation for the pause/restore claims; Vikunja pricing.

1. Overview

Vikunja runs as a Go web workload. The deployment wires together a focused set of Google Cloud services:

Capability	Google Cloud service	Notes
Compute	GKE Autopilot	Go pod, 1 vCPU / 512 MiB by default, single replica
Database	Cloud SQL for PostgreSQL 15	Required — Vikunja does not support MySQL in this module
Container build	Cloud Build + Artifact Registry	Wraps the scratch upstream image with a grafted busybox
Secrets	Secret Manager	Auto-generated VIKUNJA_SERVICE_JWTSECRET; database password
Attachments	Block PVC (StatefulSet)	Per-pod PVC at /data, where VIKUNJA_FILES_BASEPATH points
Ingress	Cloud Load Balancing	External LoadBalancer, optional custom domain + managed certificate

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.
• The pod connects to Cloud SQL over the proxy loopback with sslmode=disable. On GKE the Cloud SQL Auth Proxy sidecar listens on 127.0.0.1 (plaintext), so the entrypoint disables SSL. The same entrypoint requires SSL over the private IP on Cloud Run — it branches on whether the resolved host is loopback.
• The image is scratch-based and gets a busybox graft. The upstream vikunja/vikunja image has no shell, so the custom build copies in a static busybox to run the entrypoint. container_image_source defaults to "custom".
• VIKUNJA_SERVICE_JWTSECRET is generated automatically and stored in Secret Manager. Rotating it after first boot invalidates all active user sessions.
• Single replica by default (min_instance_count = 1, max_instance_count = 1) with session_affinity = None. Vikunja has no built-in multi-replica coordination.
• A PodDisruptionBudget keeps the pod serving through node upgrades (enable_pod_disruption_budget = true).
• Attachments live on a block PVC. Tasks, projects and users are in PostgreSQL; file attachments are written to /data (VIKUNJA_FILES_BASEPATH follows stateful_pvc_mount_path), which stateful_pvc_enabled = true (default) backs with a per-pod PVC, so the workload resolves to a StatefulSet. stateful_fs_group = 1000 makes the volume writable by Vikunja's user. NFS is off by default.
• A custom domain + static IP are enabled by default (enable_custom_domain = true, reserve_static_ip = true) so the external address survives redeploys.
• A handful of Foundation variables are declared but inert. db_host_env_var_name, db_name_env_var_name, db_password_env_var_name, db_port_env_var_name, db_user_env_var_name, redis_auth, extra_service_ports, sql_instance_name, sql_instance_base_name, network_name, gke_cluster_selection_mode, prereq_gke_subnet_cidr, binauthz_evaluation_mode, explicit_secret_values, and scripts_dir are mirrored into variables.tf purely to satisfy convention checks — this module's main.tf does not forward them, so setting them has no effect.

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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 Vikunja workload

Vikunja pods are scheduled on Autopilot, which bills for the CPU/memory the pods actually request.

• Console: Kubernetes Engine → Workloads → select the Vikunja workload to see pods 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 deploy -n "$NAMESPACE"

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

B. Cloud SQL for PostgreSQL 15

Vikunja stores all application data (tasks, projects, boards, users, teams) in a managed Cloud SQL for PostgreSQL 15 instance. Pods reach it privately through the Cloud SQL Auth Proxy sidecar over loopback (127.0.0.1, sslmode=disable); no public IP is exposed. On first deploy an initialization Job creates the application database and user.

• 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 all surfaced in the Outputs. For the connection model, automated backups, and password rotation, see App_GKE.

C. Cloud Build & Artifact Registry

Because the upstream Vikunja image is scratch-based, the module builds a wrapper image via Cloud Build (grafting in a static busybox and the entrypoint) and pushes it to Artifact Registry. App_GKE forces imagePullPolicy=Always for the custom image so a rebuild-redeploy always pulls fresh layers.

• Console: Cloud Build → History; Artifact Registry → Repositories.
• CLI:

  gcloud builds list --project "$PROJECT" --limit 5
  gcloud artifacts docker images list <region>-docker.pkg.dev/$PROJECT/<repo> --project "$PROJECT"

D. Secret Manager

One cryptographic secret is generated automatically and stored in Secret Manager: VIKUNJA_SERVICE_JWTSECRET (used to sign user session JWTs). The database password is managed separately by the foundation.

• Console: Security → Secret Manager.
• CLI:

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

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

E. File attachments

Vikunja writes file attachments to VIKUNJA_FILES_BASEPATH, which the module sets to stateful_pvc_mount_path (/data) — the per-pod block PVC — so the app and the volume cannot disagree. Without it, attachments would fall back to Vikunja's ephemeral /app/vikunja/files: the task would still list them after a restart while the download failed. The module declares no dedicated GCS bucket (storage_buckets = []).

• Console: Kubernetes Engine → Storage → the Vikunja PVC.
• CLI:

  gcloud storage buckets list --project "$PROJECT"

See App_GKE for CMEK options (manage_storage_kms_iam, enable_artifact_registry_cmek) and GCS Fuse mounts (gcs_volumes).

F. Networking & ingress

By default the workload is exposed through an external Cloud Load Balancing IP. A custom domain with a Google-managed certificate can be enabled, and a static IP is reserved so the address survives redeploys.

• 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.

G. 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

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3. Vikunja Application Behaviour

• First-deploy database setup. An initialization Job runs create-db-and-user.sh using postgres:15-alpine. It connects through the Cloud SQL Auth Proxy and idempotently creates the application database and role and grants privileges. The job is safe to re-run.
• Schema migrations on start. Vikunja applies its own schema migrations automatically on the first application startup — the db-init job only provisions an empty database, so allow extra time on the first pod to become Ready.
• VIKUNJA_SERVICE_JWTSECRET is immutable after first boot. It is generated once and written to Secret Manager. Changing it invalidates all active user sessions. Only rotate during a planned maintenance window.
• First registered account becomes the owner. Vikunja ships no pre-seeded admin. Open the external URL and register — the first account owns the instance. Then set VIKUNJA_SERVICE_ENABLEREGISTRATION = "false" in environment_variables.
• Health path. Startup and liveness probes target /health — a public, unauthenticated endpoint that returns 200 once the server binds its port.

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4. Configuration Variables

Variables are grouped exactly as they appear on the deployment platform (the {{UIMeta group=N}} tags in variables.tf). Only settings specific to or notable for Vikunja are listed in each table; every other input is inherited from App_GKE with its standard behaviour and defaults.

Group 0 — Module Metadata

Standard platform metadata (module_description, module_documentation, module_dependency, requires_services, module_services, credit_cost, require_credit_purchases, enable_purge, public_access, require_services_gcp_module, shared_users, technical_support_users, resource_creator_identity, impersonation_service_account, job_execution_wait_timeout) plus two variables declared but not referenced by this module — explicit_secret_values and scripts_dir. credit_cost defaults to 75, the same as the Cloud Run variant.

Group 1 — Project & Identity

Variable	Default	Description
project_id	(required)	Target Google Cloud project.
tenant_id	demo	Short suffix that makes resource names unique per environment.
region	us-central1	Region for the workload and regional resources.

Group 2 — Deployment Environment

Variable	Default	Description
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	vikunja	Base name for resources. Do not change after first deploy.
application_display_name	Vikunja	Human-readable name shown in the Console.
application_description	Vikunja task manager on GKE Autopilot	Workload description.
application_version	latest	Vikunja image version tag; latest builds a pinned recent release (2.3.0).

Group 4 — Runtime & Scaling

Variable	Default	Description
deploy_application	true	Set false to provision infrastructure only.
container_image_source	custom	Builds the busybox-grafted wrapper via Cloud Build.
container_image	""	Override image URI; leave empty for the auto-derived AR path.
container_build_config	{ enabled = true }	Dockerfile/context for the custom build.
enable_image_mirroring	true	Mirror the wrapper image into Artifact Registry.
min_instance_count / max_instance_count	1 / 1	Single replica — Vikunja has no multi-replica coordination.
container_port	3456	Port Vikunja's Go server listens on.
container_resources	{ cpu_limit = "1000m", memory_limit = "512Mi" }	CPU/memory limits and requests.
enable_cloudsql_volume	true	Cloud SQL Auth Proxy sidecar (loopback 127.0.0.1).
workload_type	null → StatefulSet	Resolves to a StatefulSet because the attachments PVC is enabled.

Also in this group, following standard App_GKE behaviour: enable_vertical_pod_autoscaling (false), container_protocol (http1), timeout_seconds (300), cloudsql_volume_mount_path (/cloudsql), service_annotations / service_labels ({}).

Group 5 — Identity-Aware Proxy (IAP)

Variable	Default	Description
enable_iap	false	Require Google identity auth before reaching Vikunja.
iap_authorized_users / iap_authorized_groups	[]	Identities granted access through IAP.
iap_oauth_client_id / iap_oauth_client_secret	""	OAuth 2.0 credentials. Required together when enable_iap = true.
iap_support_email	""	Support email on the IAP consent screen.

Group 6 — GKE Cluster, Networking & Environment Variables

Variable	Default	Description
environment_variables	{}	Extra VIKUNJA_* settings. Do not set VIKUNJA_DATABASE_* or VIKUNJA_SERVICE_JWTSECRET here.
secret_environment_variables	{}	Map of env var → Secret Manager secret name.
gke_cluster_name	""	Target cluster; leave empty to auto-discover the Services_GCP cluster.
namespace_name	""	Kubernetes namespace; leave empty to auto-generate.
service_type	LoadBalancer	How the Kubernetes Service is exposed.
session_affinity	None	Sticky routing (ClientIP) or None.
network_tags	[]	Node/pod network tags for firewall rule targeting.
enable_network_segmentation	false	Create Kubernetes NetworkPolicy resources.

gke_cluster_selection_mode and prereq_gke_subnet_cidr are declared for convention parity and are not referenced. extra_service_ports is declared but not forwarded by this module, so setting it has no effect. Also in this group, following standard App_GKE behaviour: secret_rotation_period (2592000s), secret_propagation_delay (30), enable_multi_cluster_service (false), configure_service_mesh (false), termination_grace_period_seconds (30), deployment_timeout (600), and prereq_subnet_cidr_override ("", set only to pin the inline VPC subnet CIDR on an existing deployment).

Group 7 — Backups & StatefulSet Configuration

Variable	Default	Description
backup_schedule	0 2 * * *	Automated Cloud SQL backup cron (UTC).
backup_retention_days	7	Retention; raise to 30–90 for production/compliance.

stateful_pvc_enabled, stateful_pvc_size, stateful_pvc_mount_path, stateful_pvc_storage_class, stateful_headless_service, stateful_pod_management_policy, stateful_update_strategy, stateful_fs_group — StatefulSet PVC templates. On by default for Vikunja: the PVC (/data, fs_group 1000) holds file attachments. Keep stateful_pvc_enabled = true.

Group 8 — Resource Quota

enable_resource_quota, quota_cpu_requests, quota_cpu_limits, quota_memory_requests, quota_memory_limits — namespace ResourceQuota. Memory values require binary unit suffixes (e.g. "4Gi").

Group 9 — Custom SQL Scripts & 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_topology_spread / topology_spread_strict	false	Distribute pods across zones.

enable_custom_sql_scripts, custom_sql_scripts_bucket, custom_sql_scripts_path, custom_sql_scripts_use_root — optional post-provisioning SQL script execution against the database.

Group 10 — Observability & Health

Variable	Default	Description
startup_probe_config	HTTP /health, 30s delay, 30 × 10s failure window	Startup probe; wide retry window for first-boot migrations.
health_check_config	HTTP /health, 30s delay	Liveness probe.
uptime_check_config	disabled, path /health	Optional Cloud Monitoring uptime check.
alert_policies	[]	Optional metric alert policies.

Group 11 — Workload Automation

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

Group 12 — CI/CD, GitHub & Binary Authorization

Standard App_GKE Cloud Build / Cloud Deploy integration — see App_GKE. Key inputs: enable_cicd_trigger, github_repository_url, github_token, github_app_installation_id, cicd_trigger_config, enable_cloud_deploy, cloud_deploy_stages, enable_binary_authorization. binauthz_evaluation_mode is declared for convention parity and is not referenced.

Group 13 — Filesystem (NFS)

Variable	Default	Description
enable_nfs	false	Not needed — attachments are on the block PVC.
nfs_mount_path	/mnt/nfs	Mount path inside the container.
nfs_volume_name	nfs-data-volume	Volume name for the mount.
nfs_instance_name / nfs_instance_base_name	"" / app-nfs	Existing NFS VM to reuse, or the base name for an inline one.

Group 14 — Cloud Storage & Artifact Registry

Variable	Default	Description
create_cloud_storage	true	Create additional GCS buckets.
storage_buckets	[]	Vikunja declares no bucket by default.
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 15 — Redis

Variable	Default	Description
enable_redis	false	Vikunja does not use Redis; provided for Foundation convention parity.
redis_host / redis_port	"" / 6379	Redis connection details, only meaningful if enable_redis = true.

redis_auth is declared but not forwarded by this module, so setting it has no effect.

Group 16 — Database Configuration

Variable	Default	Description
database_type	POSTGRES	Cloud SQL engine; fixed to PostgreSQL 15 by Vikunja_Common regardless of this value.
application_database_name	vikunja	PostgreSQL database name. Immutable after first deploy.
application_database_user	vikunja	Application database user. Immutable after first deploy.
database_password_length	32	Generated password length (16–64).
enable_auto_password_rotation	false	Zero-downtime database password rotation.
rotation_propagation_delay_sec	90	Seconds to wait after rotation before restarting pods.
enable_postgres_extensions / postgres_extensions	false / []	Optional PostgreSQL extension installation.

enable_mysql_plugins / mysql_plugins are not applicable to Vikunja (PostgreSQL only). sql_instance_name, sql_instance_base_name, and the db_*_env_var_name set (db_host_env_var_name, db_name_env_var_name, db_password_env_var_name, db_port_env_var_name, db_user_env_var_name) are declared for convention parity and are not referenced/forwarded by this module.

Group 17 — Backup Import / Restore

enable_backup_import, backup_source, backup_file, backup_format — restore the application database from a backup file on deploy.

Group 19 — Custom Domain, Static IP & Networking

Variable	Default	Description
enable_custom_domain	true	Provision Ingress for custom hostnames + managed certificate.
application_domains	[]	Hostnames to serve.
reserve_static_ip	true	Stable external IP across redeploys.
static_ip_name	""	Name for the static IP; leave empty to auto-generate.

network_name is declared for convention parity and is not referenced (the network is auto-discovered).

Group 21 — Cloud Armor & CDN

enable_cloud_armor, admin_ip_ranges, cloud_armor_policy_name, enable_cdn — attach a Cloud Armor WAF and Cloud CDN to the GKE Ingress backend.

Group 22 — VPC Service Controls & Audit Logging

enable_vpc_sc, vpc_cidr_ranges, vpc_sc_dry_run, organization_id, enable_audit_logging — enforce a VPC-SC perimeter and detailed Cloud Audit Logs.

All other inputs follow standard App_GKE behaviour.

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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 Vikunja.
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.
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 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.

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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 StatefulSet/Deployment mismatch, memory quota values without binary suffixes, an out-of-range container_port/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
VIKUNJA_SERVICE_JWTSECRET (auto-generated)	Never rotate after first boot	Critical	Rotating it invalidates all active user sessions, forcing immediate re-login for everyone.
application_database_name / application_database_user	Set once	Critical	Immutable after first deploy; renaming recreates the DB/user and destroys all data.
enable_backup_import	false unless restoring	Critical	Enabling without a valid backup source/file fails the import job.
stateful_pvc_enabled	true	High	Without the PVC, file attachments live on the pod's ephemeral disk and are lost on every pod restart.
container_image_source	custom	High	prebuilt deploys the raw scratch image with no shell/entrypoint mapping — the container cannot map DB_* and fails.
enable_cloudsql_volume	true	High	The Auth Proxy sidecar is required for PostgreSQL connectivity; disabling it is blocked by a plan-time validation guard.
min_instance_count	1	Medium	The variable's own validation allows 0–1000 and there is no plan-time guard rejecting 0 — App_GKE's Deployment logic silently coerces min_instance_count=0 to a min_replicas of 1 at apply time (local.min_instance_count > 0 ? local.min_instance_count : 1), so the deployed replica count silently diverges from what was configured rather than failing with an error.
VIKUNJA_SERVICE_ENABLEREGISTRATION (env var)	"false" after first admin	High	Leaving registration open allows anyone with the URL to create an account.
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 the pod during maintenance with no availability guard.
backup_retention_days	7 (raise for prod)	Medium	Too short for compliance retention.
db_*_env_var_name, redis_auth, extra_service_ports, sql_instance_name/sql_instance_base_name, network_name, gke_cluster_selection_mode, prereq_gke_subnet_cidr, binauthz_evaluation_mode	Leave at default	Low	Declared for Foundation convention parity but not forwarded/referenced by this module — setting them has no effect on the deployment.

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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. Vikunja-specific application configuration shared with the Cloud Run variant is described in Vikunja_Common.

Related guides

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