TechnitiumDNS on GKE Autopilot — Lab Guide

📖 Configuration Guide

Overview

Estimated time: 45–90 minutes

⚠️ Before you start: this module deploys Technitium's web admin console + REST API only (port 5380/HTTP). Technitium's core DNS resolver function (port 53/udp+tcp) cannot be exposed through this module's standard HTTP(S) Gateway pattern. This lab covers managing DNS zones/records via the console — it does NOT make this deployment usable as an actual DNS resolver from any client.

Technitium DNS Server is an open-source, self-hosted authoritative/recursive DNS server with a full-featured web console for managing zones, records, DNS-based blocking, and forwarders — no external database required. This lab takes you through the full operational lifecycle of the TechnitiumDNS on GKE Autopilot module on Google Cloud: deploy it, access and verify it, run it day-to-day, observe it, diagnose common problems, and tear it down.

The lab focuses on operating the GKE module and the Google Cloud platform, not on TechnitiumDNS's DNS-server product features. For the complete list of provisioned services and every configuration input (organised by group), see the Configuration Guide — this lab deliberately does not duplicate that detail so it stays accurate over time.

Objectives

By the end of this lab you will be able to:

• Deploy the module from the RAD platform and locate the resources it provisions.
• Connect to the GKE cluster and access the running workload, including a first login and a zone-creation smoke test.
• Perform day-2 operations — inspect, update, and manage secrets and storage.
• Observe the workload with Cloud Logging and Cloud Monitoring.
• Diagnose and resolve the most common deployment and runtime issues.
• Tear the deployment down cleanly.

Prerequisites

• Services_GCP (provides the VPC, GKE Autopilot cluster, Artifact Registry, and shared service accounts this module depends on). You do not need to deploy this yourself first — the platform automatically detects whether it already exists in the target project and provisions it before this module if not (see Task 1).
• A Google Cloud project with billing enabled.
• gcloud CLI and kubectl installed; gcloud auth login and gcloud auth application-default login completed.
• Project Owner (or equivalent) IAM on the project.
• Bringing your own project? Before the first deploy into it, the deployment confirmation dialog asks you to prove you control it (Get verification code, run the commands it shows as a project Owner, then Verify) and to give the RAD deployment service account the Owner role. A project RAD creates for you needs neither.
• Advanced mode for later changes. The create form asks only for the first page of inputs (and, in a project RAD creates for you, little more than the tenant name and region). Every other input in the Configuration Guide — including the scaling and version inputs in the Day-2 tasks — is changed afterwards with Update on the deployment's page after ticking Enable advanced mode, which needs a credit balance that covers the update's estimated build cost (updates never carry a module fee). On a lab environment only an administrator can use Advanced mode.
• RAD platform access with permission to deploy modules into the project.

Set these shell variables once; every task below reuses them:

export PROJECT="<your-gcp-project-id>"
export REGION="us-central1"           # the region you deploy into

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Task 1 — Deploy the module [Automated]

1. Open Solutions → Solution Catalog → RAD modules in the RAD platform top navigation, open TechnitiumDNS (GKE) from the Platform Modules list to start configuration, choose Configuration Form under How would you like to configure this deployment? (the form opens on the Conversational Assistant if you hold purchased credits or are a partner or administrator), set project_id, and review the inputs. Configure only what you need — the Configuration Guide documents every input by group, with defaults. Click Deploy Module, review the estimated cost in the Deployment Confirmation dialog when it appears and click Submit (if the dialog then adds a confirmation step, such as verifying a project you bring, complete it and click Confirm), which opens the deployment status page with real-time logs. If deploying alongside TechnitiumDNS_CloudRun on the same tenant, set a distinct tenant_id (e.g. "gke") to avoid a naming collision.

2. The platform deploys a single Deployment workload into the GKE Autopilot cluster running the official prebuilt technitium/dns-server image, plus one Cloud Storage bucket (mounted at /etc/dns) and one auto-generated admin-password secret. No database is provisioned. Since the image is prebuilt (no Cloud Build step) and there is no database-initialisation job to wait for, a first deploy is typically fast (roughly 8–15 minutes, dominated by workload scheduling).

3. Connect to the cluster and discover the namespace with a name-agnostic filter:

   CLUSTER=$(gcloud container clusters list --project="$PROJECT" --format="value(name)" --limit=1)
   gcloud container clusters get-credentials "$CLUSTER" --region="$REGION" --project="$PROJECT"
   
   NS=$(kubectl get ns -o name | grep technitiumdns | head -1 | cut -d/ -f2)
   echo "Cluster: $CLUSTER   Namespace: $NS"
   kubectl get all -n "$NS"

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Task 2 — Access & verify [Manual]

1. Confirm the workload is running and find its external address:

   kubectl get pods,svc -n "$NS"
   EXTERNAL_IP=$(kubectl get svc -n "$NS" \
     -o jsonpath='{.items[?(@.spec.type=="LoadBalancer")].status.loadBalancer.ingress[0].ip}')
   echo "External IP: $EXTERNAL_IP"

2. Confirm the service is healthy — the console root page responds as soon as the server binds its port, with no database dependency to wait on:

   curl -s -o /dev/null -w '%{http_code} %{size_download}\n' "http://${EXTERNAL_IP}/"
   # expect 200 and a large body

3. Retrieve the auto-generated admin password:

   SECRET=$(gcloud secrets list --project="$PROJECT" --filter="name~admin-password" \
     --format="value(name)" --limit=1)
   gcloud secrets versions access latest --secret="$SECRET" --project="$PROJECT"

4. Open http://${EXTERNAL_IP}/ in a browser and log in as admin with that password. Immediately change the password from the console's own user-management page — Technitium only reads DNS_SERVER_ADMIN_PASSWORD on the very first boot.

5. Run a zone-creation smoke test: in Zones → Add Zone, create a simple primary zone (e.g. example.test), add an A record, save, then delete the pod (kubectl delete pod <pod> -n "$NS") to force a reschedule, and confirm the zone and record are still present once the new pod is Ready — proving the persisted /etc/dns volume genuinely survives a pod restart.

6. Remember: no client anywhere can resolve DNS queries against this deployment. The console lets you fully manage zone data, but only the web console/API is reachable — not port 53.

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Task 3 — Operate & keep it running (Day-2) [Manual]

1. Inspect the workload — deployment and pods:

   kubectl get deploy,pods -n "$NS"
   kubectl describe deploy -n "$NS"

2. Update the application version by changing the version input in the RAD platform and applying it via Update; a rolling update replaces the pod with the newly-tagged prebuilt image. Pin an explicit version in production rather than relying on latest.

3. Manage secrets and storage:

   kubectl get secrets -n "$NS"
   gcloud secrets list --project="$PROJECT" --filter="name~technitiumdns"
   kubectl get pvc -n "$NS"          # only present when stateful_pvc_enabled = true

   Only the auto-generated DNS_SERVER_ADMIN_PASSWORD appears in Secret Manager by default.

4. Switch to a block PVC for stronger write-locking guarantees, if desired: set stateful_pvc_enabled = true (with stateful_pvc_mount_path = "/etc/dns", or leave workload_type unset to auto-select StatefulSet) and apply via Update. The module automatically disables the GCS FUSE volume in that case to avoid a double-mount.

5. Enable Identity-Aware Proxy for a production deployment — set enable_iap = true with authorized users/groups (and the required OAuth client ID/secret) and apply via Update.

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Task 4 — Observe: Logging & Monitoring [Manual]

1. Logs — from kubectl or the Logs Explorer:

   kubectl logs -n "$NS" deploy/"$(kubectl get deploy -n "$NS" -o jsonpath='{.items[0].metadata.name}')" --tail=50

   Logs Explorer filter: resource.type="k8s_container" AND resource.labels.namespace_name="<namespace>".

2. Monitoring — open the GKE / Kubernetes dashboards and review pod CPU and memory utilisation, restart counts, and request metrics. If a Cloud Monitoring uptime check is enabled, review Monitoring → Uptime checks and Alerting → Policies.

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Task 5 — Troubleshoot & debug [Manual]

Durable techniques for the failure modes you are most likely to hit. These are platform-level diagnostics and do not change with TechnitiumDNS releases.

• Pod not Ready / CrashLoopBackOff: inspect events and logs. The startup and liveness probes both target /, which should return 200 within seconds of boot — TechnitiumDNS has no database to wait on, so a slow or failing probe usually points at a container or storage-mount issue rather than a downstream dependency.

  kubectl describe pod -n "$NS" <pod>          # Events section shows scheduling/probe/mount errors
  kubectl logs -n "$NS" <pod> --previous       # logs from the crashed container

• "I can't resolve DNS against this deployment": this is expected — see the disclosure at the top of this guide. This module intentionally exposes only the web console/API, never port 53.
• Zones/records disappear after a pod restart: confirm the config Cloud Storage bucket or PVC is actually mounted:

  kubectl exec -n "$NS" <pod> -- ls -l /etc/dns
  kubectl get pvc -n "$NS"    # if stateful_pvc_enabled = true

• Can't log in with the Secret Manager password: remember it only applies on the very first boot. If the console was ever started before with the same persisted volume, the password already on disk wins — use the console's own password-reset flow.
• Pending pod / no external IP: check kubectl describe pod events for resource or quota issues, and confirm the LoadBalancer Service has an assigned IP:

  kubectl get svc -n "$NS"

• A stateful_pvc_enabled switch left both a GCS volume AND a PVC: confirm only one is mounted at /etc/dns — the module should automatically disable the GCS volume when the PVC is enabled; if both somehow appear, redeploy after clearing state.
• Image pull errors: confirm the image exists in Artifact Registry (if mirrored) and the node service account can pull it.

See the Configuration Guide's Configuration Pitfalls & Sensible Defaults section for setting-specific gotchas (including the no-DNS-resolver scoping decision and the PVC mount-path requirement).

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Task 6 — Tear down [Automated]

On the Deployments page, open the deployment and click the Trash icon (Delete). Delete runs terraform destroy and is irreversible (the deployment record is retained for history). If a deployment is stuck and the RAD platform can no longer manage it (for example after manual changes that conflict with the Terraform state), use Purge instead (from the same Delete dialog) — it removes the deployment from RAD's records without destroying the cloud resources (it makes RAD forget the deployment). This removes everything the module created — the Kubernetes workload and namespace, any PVC, the config Cloud Storage bucket, the admin-password secret, and Artifact Registry images. There is no Cloud SQL database to clean up (TechnitiumDNS provisions none). Resources owned by Services_GCP (the VPC, GKE cluster, shared registry) are managed separately and are not removed here.

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Summary

Task	Type	Outcome
1 — Deploy	Automated	Module deploys a single GKE workload running the prebuilt TechnitiumDNS image, one config bucket, one secret
2 — Access & verify	Manual	Connect to the cluster; health check passes; first login succeeds; a zone/record survives a pod restart
3 — Operate	Manual	Inspect workload, update version, manage secrets/storage, optionally switch to a block PVC, enable IAP
4 — Observe	Manual	Query Cloud Logging; review Cloud Monitoring metrics and uptime check
5 — Troubleshoot	Manual	Diagnose pod, storage-persistence, scheduling, and image-pull issues; confirm no-DNS-resolver scoping
6 — Tear down	Automated	Delete (Trash) removes all module resources