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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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
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.
• NFS is disabled by default. Vikunja stores data in PostgreSQL; enable NFS only if you need durable file attachments at /app/vikunja/files.
• A custom domain + static IP are enabled by default (enable_custom_domain = true, reserve_static_ip = true) so the external address survives redeploys.

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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. Cloud Storage & file attachments (optional)

Vikunja stores file attachments on the pod filesystem at /app/vikunja/files. Enable NFS and mount it over that path for durable attachments; the module declares no dedicated GCS bucket by default. NFS-backed GKE apps deploy with the Recreate strategy to avoid two pods contending for the same volume.

• Console: Filestore / Compute Engine (NFS VM) when enable_nfs = true.
• CLI:

  gcloud storage buckets list --project "$PROJECT"

See App_GKE for CMEK options and GCS Fuse mounts.

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. Only settings specific to or notable for Vikunja 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_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 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_version	latest	Vikunja image version tag; latest builds a pinned recent release (2.3.0).
deploy_application	true	Set false to provision infrastructure only.

Group 4 — Runtime & Scaling

Variable	Default	Description
container_image_source	custom	Builds the busybox-grafted wrapper via Cloud Build.
container_resources	{ cpu_limit = "1000m", memory_limit = "512Mi" }	CPU/memory limits and requests.
container_port	3456	Port Vikunja's Go server listens on.
min_instance_count	1	Minimum replicas.
max_instance_count	1	Single replica — Vikunja has no multi-replica coordination.
enable_cloudsql_volume	true	Cloud SQL Auth Proxy sidecar (loopback 127.0.0.1).
enable_image_mirroring	true	Mirror the wrapper image into Artifact Registry.
workload_type	Deployment	Stateless Deployment (StatefulSet not needed — state is in PostgreSQL).

Group 5 — Environment Variables & Secrets

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.
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.
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.

Group 7 — StatefulSet

stateful_pvc_enabled, stateful_pvc_size, stateful_pvc_mount_path, stateful_pvc_storage_class, stateful_headless_service, stateful_pod_management_policy, stateful_update_strategy — StatefulSet PVC templates. Not recommended for Vikunja; state lives in PostgreSQL.

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.

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 — Jobs & Scheduled Tasks

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 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	false	Enable for durable file attachments at /app/vikunja/files.
nfs_mount_path	/mnt/nfs	Mount path inside the container.

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 16 — Database Backend

Variable	Default	Description
database_type	POSTGRES	Cloud SQL engine; fixed to PostgreSQL 15 by Vikunja_Common.
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 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 Cloud SQL 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.
application_domains	[]	Hostnames to serve.
reserve_static_ip	true	Stable external IP across redeploys.

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.
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.

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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_uri fails the import job.
enable_nfs (for attachments)	true if attachments matter	High	Without NFS, 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	High	GKE requires min ≥ 1; the validation guard rejects invalid values.
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.

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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.