Version: 1.3.0

Deploy StorageLink with Helm Chart on GKE

TLDR - Quick Summary
What: Deploy StorageLink on GKE using a Helm chart with bundled or external PostgreSQL
Steps: Create GKE cluster, download the chart, run helm install
Quick start:
helm install storagelink ./storagelink \
  --namespace storagelink --create-namespace \
  --set license.key=trial \
  --set postgresql.auth.password=$(openssl rand -hex 16) \
  --set admin.username=admin \
  --set admin.password='YourSecurePassword1!'

Overview

The StorageLink Helm chart simplifies deploying StorageLink on Google Kubernetes Engine (GKE). It handles creating all Kubernetes resources (Deployments, Services, ConfigMaps, Secrets, PVCs, ServiceAccounts, NetworkPolicies, PodDisruptionBudgets) and supports two database modes:

Bundled PostgreSQL (default) — runs a PostgreSQL container inside the cluster using the Bitnami subchart. Good for testing and simple deployments.
External database — connects to a managed Cloud SQL for PostgreSQL instance. Recommended for production.

Container Reference

For detailed configuration options (TLS modes, client IP preservation, security context, LFS mode, image verification, and more), see the Container Deployment Reference.

Architecture

                    ┌──────────────────────────────────────────────┐
                    │     Google Kubernetes Engine (GKE)           │
                    │           Namespace: storagelink             │
                    │                                              │
  HTTPS (443)       │   ┌────────────┐    ┌────────────────┐       │
  ──────────────────┼──►│  Admin UI  │───►│    Backend     │       │
                    │   │ (Nginx)    │    │ (Spring Boot)  │       │
                    │   │            │    │  Port 8080 API │       │
                    │   └────────────┘    └───────┬────────┘       │
                    │                             │                │
                    │                     ┌───────▼────────┐       │
                    │                     │  PostgreSQL 16 │       │
                    │                     │  (bundled or   │       │
                    │                     │   external)    │       │
                    │                     └────────────────┘       │
                    └──────────────────────────────────────────────┘

Components:

Backend — StorageLink API server (Spring Boot). Handles cloud storage operations and user management.
Admin UI — Web-based administration dashboard (Nginx). Exposed via a LoadBalancer on port 443.
PostgreSQL — Stores user accounts and configuration data.

Prerequisites

A Google Cloud project with billing enabled
gcloud CLI installed and configured
Helm 3 installed
kubectl installed
Network access to Docker Hub, where the StorageLink images are published: thorntech/storagelink-backend and thorntech/storagelink-ui

Download the Helm chart

Download the StorageLink Helm chart archive and extract it:

curl -LO https://help.thorntech.com/storagelink/downloads/storagelink-gcp-0.3.0.tgz
tar xzf storagelink-gcp-0.3.0.tgz

This creates a storagelink/ directory containing the chart (version 0.3.0, StorageLink 1.3.0), with GKE defaults already set. All helm install commands below reference this directory as ./storagelink.

Step 1: Create a GKE cluster

gcloud container clusters create storagelink-gke \
  --zone us-central1-a \
  --num-nodes 2 \
  --machine-type e2-standard-2 \
  --enable-network-policy

Get credentials for kubectl:

gcloud container clusters get-credentials storagelink-gke --zone us-central1-a

Verify the cluster is ready:

kubectl get nodes

Step 2: Create the namespace

kubectl create namespace storagelink
kubectl label namespace storagelink pod-security.kubernetes.io/enforce=restricted

The chart is compatible with the restricted Pod Security Standard, so enforcing it is recommended.

The images are public on Docker Hub (thorntech/storagelink-backend and thorntech/storagelink-ui), so no pull secret is needed. The tag defaults to the chart's appVersion (1.3.0). To pull from your own registry or mirror, set backend.image.repository, ui.image.repository and, if the registry needs credentials, imagePullSecrets.

Step 3: Install the Helm chart

Option A: Bundled PostgreSQL (quickstart)

This is the simplest option — a PostgreSQL container runs alongside the backend inside your cluster.

helm install storagelink ./storagelink \
  --namespace storagelink \
  --set license.key=trial \
  --set postgresql.auth.password=$(openssl rand -hex 16) \
  --set admin.username=admin \
  --set admin.password='YourSecurePassword1!'

After a few minutes, all pods should be running:

kubectl get pods -n storagelink

Expected output:

NAME                                   READY   STATUS    RESTARTS   AGE
storagelink-backend-xxxxx              1/1     Running   0          2m
storagelink-backend-yyyyy              1/1     Running   0          2m
storagelink-postgresql-0               1/1     Running   0          2m
storagelink-ui-xxxxx                   1/1     Running   0          2m
storagelink-ui-yyyyy                   1/1     Running   0          2m

Option B: Cloud SQL for PostgreSQL (production)

For production deployments, use a managed Cloud SQL for PostgreSQL instance.

Create the database

# Create a Cloud SQL instance
gcloud sql instances create storagelink-pg \
  --database-version=POSTGRES_16 \
  --tier=db-f1-micro \
  --edition=enterprise \
  --region=us-central1 \
  --root-password='<your-strong-password>' \
  --authorized-networks=0.0.0.0/0 \
  --storage-size=10GB

# Create the database
gcloud sql databases create swift_gw --instance=storagelink-pg

Get the instance IP:

gcloud sql instances describe storagelink-pg \
  --format="value(ipAddresses[0].ipAddress)"

tip

For production, use a private IP or the Cloud SQL Auth Proxy instead of --authorized-networks=0.0.0.0/0.

Install with external database

helm install storagelink ./storagelink \
  --namespace storagelink \
  --set license.key=trial \
  --set postgresql.enabled=false \
  --set externalDatabase.host=<cloud-sql-ip> \
  --set externalDatabase.username=postgres \
  --set externalDatabase.password='<your-strong-password>' \
  --set externalDatabase.jdbcParams='?sslmode=require' \
  --set admin.username=admin \
  --set admin.password='YourSecurePassword1!'

note

Cloud SQL uses the postgres user by default, unlike the bundled PostgreSQL which uses swiftgw.

Step 4: Access the Admin UI

Get the external IP of the UI service:

kubectl get svc storagelink-ui -n storagelink

It may take 1–2 minutes for GCP to assign the external IP. Once available:

NAME             TYPE           CLUSTER-IP       EXTERNAL-IP      PORT(S)         AGE
storagelink-ui   LoadBalancer   34.118.236.101   34.172.240.196   443:30971/TCP   2m

Open https://<EXTERNAL-IP> in your browser. You will see a certificate warning because the chart generates a self-signed TLS certificate by default — this is expected for testing.

If you provided admin.username and admin.password, log in with those credentials. Otherwise, you will be prompted to create your admin account on first access.

caution

If no admin credentials were provided and the UI is publicly accessible, the first person to reach the UI can create the admin account. See Security considerations below.

Security considerations

Admin account

The admin.username and admin.password values trigger a post-install Helm Job that waits for the backend to become healthy, then calls the setup API to create the admin account. If an admin account already exists (e.g., on helm upgrade), the Job detects this and exits successfully without changes.

Restrict Admin UI access

Lock down the Admin UI to specific IP addresses using loadBalancerSourceRanges:

helm install storagelink ./storagelink \
  --namespace storagelink \
  --set 'ui.service.loadBalancerSourceRanges[0]=203.0.113.50/32' \
  --set 'ui.service.loadBalancerSourceRanges[1]=198.51.100.0/24' \
  # ... other values

Built-in hardening

The Helm chart includes these security defaults:

Non-root containers — the backend runs as the image's own user (UID 1000, group 0; the chart does not pin runAsUser), the UI as UID 1000
Read-only root filesystem — enabled on the backend container
Dropped capabilities — all Linux capabilities are dropped
NetworkPolicies — restrict pod-to-pod and egress traffic
ServiceAccounts — dedicated accounts with token automount disabled
PodDisruptionBudgets — ensure availability during node maintenance
Backend not externally exposed — backend Service is ClusterIP, preventing X-Forwarded-For spoofing that would defeat login lockout and forge audit source IPs
Client IP preservation — UI Service uses externalTrafficPolicy: Local to preserve the client's real source IP for audit logging and login lockout
Zero-downtime rolling updates — UI Deployment uses maxSurge: 1, maxUnavailable: 0 to avoid dropped connections under the Local traffic policy

OpenShift

OpenShift's restricted-v2 SecurityContextConstraint assigns user and group IDs from the namespace's range and rejects pods that set their own. Install with:

--set global.compatibility.openshift.adaptSecurityContext=force

This removes every hard-coded UID, GID and fsGroup from the chart, including the bundled PostgreSQL. Use it only on OpenShift: on EKS, AKS and GKE the IDs are required (the fsGroup makes block volumes writable).

Custom TLS certificate

To use your own TLS certificate instead of the auto-generated self-signed one:

helm install storagelink ./storagelink \
  --namespace storagelink \
  --set-file ui.tls.certificate=path/to/tls.crt \
  --set-file ui.tls.privateKey=path/to/tls.key \
  # ... other values

Configuration reference

Key values

Parameter	Description	Default
`backend.image.repository`	Backend image. Public on Docker Hub; override to use your own registry or mirror	`thorntech/storagelink-backend`
`backend.image.tag`	Backend image tag. Empty uses the chart's `appVersion` (`1.3.0`); that tag must exist in the repository	`""`
`ui.image.repository`	UI image. Public on Docker Hub; override to use your own registry or mirror	`thorntech/storagelink-ui`
`ui.image.tag`	UI image tag. Empty uses the chart's `appVersion` (`1.3.0`)	`""`
`imagePullSecrets`	Pull secrets, only needed for a private registry or mirror	`[]`
`admin.username`	Initial admin username	`""`
`admin.password`	Initial admin password	`""`
`license.key`	License for unattended installs (`trial` for evaluation, or your license). If empty, license the deployment from the admin UI after the first sign-in (Settings → License): start the free 30-day trial or activate a purchased license. Until then non-administrator users cannot sign in and file transfers are blocked. See Purchasing a License.	`""`
`config.cloudProvider`	Cloud provider hint: `azure`, `aws`, or `gcp`	`gcp`
`backend.replicaCount`	Number of backend replicas	`2`
`ui.replicaCount`	Number of UI replicas	`2`
`ui.tls.certificate`	Custom TLS certificate (PEM)	`""` (self-signed)
`ui.tls.privateKey`	Custom TLS private key (PEM)	`""`
`ui.service.loadBalancerSourceRanges`	Restrict Admin UI to specific IPs	`[]`
`ui.externalTlsTermination`	Skip in-pod TLS when a load balancer handles TLS	`false`
`postgresql.enabled`	Use bundled PostgreSQL	`true`
`postgresql.auth.password`	Bundled PostgreSQL password	`""`
`externalDatabase.host`	External PostgreSQL hostname	`""`
`externalDatabase.password`	External PostgreSQL password	`""`
`externalDatabase.jdbcParams`	Additional JDBC params (e.g., `?sslmode=require`)	`""`
`localStorage.enabled`	Store files on a PersistentVolume instead of cloud storage (LFS mode)	`false`
`localStorage.mountPath`	Absolute path the volume is mounted at — must be outside `/opt/swiftgw`	`/mnt/data`
`localStorage.persistence.size`	Size of the PersistentVolumeClaim	`50Gi`
`localStorage.persistence.storageClassName`	Storage class for the LFS volume. Must support `ReadWriteMany` — see Local File Storage	`standard-rwx`
`localStorage.persistence.accessMode`	Must be `ReadWriteMany` when running more than one backend replica	`ReadWriteMany`
`networkPolicy.enabled`	Enable NetworkPolicies	`true`
`podDisruptionBudget.enabled`	Enable PodDisruptionBudgets	`true`
`global.compatibility.openshift.adaptSecurityContext`	Set `force` on OpenShift — see OpenShift	unset (`disabled`)

Local File Storage

Local File Storage (LFS) mode stores files on a PersistentVolume instead of cloud storage. Enable it with --set localStorage.enabled=true. The chart creates the storagelink-data PVC, mounts it at /mnt/data on every backend replica, and creates the first storage connection pointing at it on first launch.

On GKE the chart defaults the LFS volume to the standard-rwx storage class (Filestore). Enable the Filestore CSI driver on the cluster first, or the class does not exist:

gcloud container clusters update storagelink-gke \
  --update-addons=GcpFilestoreCsiDriver=ENABLED \
  --zone <zone>

Filestore bills for the instance's provisioned size, which can be larger than the PVC request. standard-rwx is zonal; use enterprise-rwx to survive a zone outage. The Filestore export is owned by root with mode 0755; the backend's fsGroup: 0 makes it writable, so do not remove it. To use a different class, set localStorage.persistence.storageClassName.

The volume must be ReadWriteMany, because both backend replicas read and write the same files. For mount-path rules, see Local File Storage (LFS) Mode.

Upgrading

helm upgrade storagelink ./storagelink \
  --namespace storagelink \
  --reuse-values

danger

If you used --set flags during install, you must pass the same values during upgrade (or use --reuse-values). Helm does not persist --set values between releases.

Upgrading from chart 0.2.0

Chart 0.2.0 left the LFS storage class empty, so Kubernetes filled in the cluster's default class when it created the PVC. 0.3.0 defaults to standard-rwx, and a PVC's storage class cannot be changed after it is created. If you enabled localStorage on 0.2.0, helm upgrade fails until you do one of the following:

PVC Pending (the default class is ReadWriteOnce, so it usually never bound): it holds no data, so delete it before upgrading:
```
kubectl delete pvc storagelink-data -n storagelink
```

PVC Bound: keep it and pin the class it already has:

kubectl get pvc storagelink-data -n storagelink -o jsonpath='{.spec.storageClassName}'
helm upgrade storagelink ./storagelink --namespace storagelink --reuse-values \
  --set localStorage.persistence.storageClassName=<that-class>

If localStorage was never enabled, upgrade normally.

Uninstalling

helm uninstall storagelink --namespace storagelink

helm uninstall leaves two PersistentVolumeClaims in place, so your data is not deleted:

data-storagelink-postgresql-0 — the bundled PostgreSQL database, if used
storagelink-data — the LFS volume, if localStorage was enabled (the chart marks it helm.sh/resource-policy: keep)

A reinstall reattaches them only if it uses the same release name (storagelink) and namespace. With the bundled PostgreSQL, also pass the same postgresql.auth.password, or the backend cannot open the kept database.

To remove them once the data is no longer needed:

kubectl delete pvc data-storagelink-postgresql-0 storagelink-data -n storagelink

danger

Deleting the PersistentVolumeClaims permanently deletes the underlying volumes (Persistent Disks, and the LFS file share) and all data stored on them. Back up any important data first.

Troubleshooting

Backend pod CrashLoopBackOff

Check the backend logs:

kubectl logs -n storagelink -l app.kubernetes.io/component=backend --tail=50

Common causes:

Database connection failed — Verify credentials and that the Cloud SQL instance is running and accessible. Check authorized networks.
Insufficient memory — The backend requires at least 2Gi of memory.

Backend stuck on "Waiting for changelog lock"

This happens when a previous backend instance crashed during database migrations. The Helm chart includes an init container that clears stale locks automatically on every pod start.

PVCs stuck in Pending

kubectl get storageclass
kubectl describe pvc -n storagelink

Bundled PostgreSQL (data-storagelink-postgresql-0) uses the cluster's default storage class.
LFS volume (storagelink-data) uses standard-rwx. If the class is missing or misconfigured, the PVC stays Pending and so do the backend pods — see Local File Storage. If you upgraded from chart 0.2.0, see Upgrading from chart 0.2.0.

UI pod CrashLoopBackOff

Check the UI logs:

kubectl logs -n storagelink -l app.kubernetes.io/component=ui --tail=50

Common causes:

TLS certificate issue — The chart auto-generates a self-signed certificate. If you provided a custom certificate, verify both ui.tls.certificate and ui.tls.privateKey are valid PEM and match each other.

External IP stuck on \<pending>

kubectl describe svc storagelink-ui -n storagelink

Check the Events section for error messages. Common causes include insufficient project quota or the GKE cluster lacking the necessary permissions to create external load balancers.

Backend pod not becoming Ready

The backend takes 60–90 seconds to start on first launch due to database migrations. Check readiness probe status:

kubectl describe pod -n storagelink -l app.kubernetes.io/component=backend

Resource summary

Component	Memory (request/limit)	CPU (request/limit)	Storage
PostgreSQL (bundled)	256Mi / 512Mi	250m / 500m	20Gi
Backend (x2)	2Gi / 3Gi	500m / 1500m	—
Admin UI (x2)	128Mi / 256Mi	100m / 500m	—
Total	~4.5Gi / ~7Gi	1450m / 4000m	20Gi

Deploy StorageLink with Helm Chart on GKE

Overview​

Architecture​

Prerequisites​

Download the Helm chart​

Step 1: Create a GKE cluster​

Step 2: Create the namespace​

Step 3: Install the Helm chart​

Option A: Bundled PostgreSQL (quickstart)​

Option B: Cloud SQL for PostgreSQL (production)​

Create the database​

Install with external database​

Step 4: Access the Admin UI​

Security considerations​

Admin account​

Restrict Admin UI access​

Built-in hardening​

OpenShift​

Custom TLS certificate​

Configuration reference​

Key values​

Local File Storage​

Upgrading​

Upgrading from chart 0.2.0​

Uninstalling​

Troubleshooting​

Backend pod CrashLoopBackOff​

Backend stuck on "Waiting for changelog lock"​

PVCs stuck in Pending​

UI pod CrashLoopBackOff​

External IP stuck on \<pending>​

Backend pod not becoming Ready​

Resource summary​