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Ghost on GKE Autopilot
Ghost is a modern open-source publishing platform powering 2M+ publications with built-in membership, subscriptions, and newsletters. This module deploys Ghost 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 Ghost 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 Ghost costs on RAD, and how that compares
Running Ghost in your own Google Cloud project costs about US$149.81/month in Google Cloud charges, on top of a one-time 300-credit RAD module fee (270 credits — 10% lower — in a RAD-managed project). Ghost is a modern open-source publishing platform with 48,000+ GitHub stars, powering 2M+ publications and used by leading independent media brands. If you deploy into a RAD-managed project, you can pause the whole thing for free and pick it back up later — see "Pause it for free" below.
Ghost is also available on Cloud Run — see the Cloud Run guide for the lower-cost option; this guide covers the GKE variant.
What you pay on RAD
| Own project | RAD-managed project | |
|---|---|---|
| Module fee | 300 credits (one-time) | 270 credits (one-time, 10% lower) |
| Build time | ~3–6 credits (one-time, per build) | ~3–6 credits (one-time, per build) |
| Google Cloud running cost | ~US$149.81/month, billed to your own Google billing account at list price | ~115 credits/day (~US$11.50/day), metered hourly at list price plus RAD's margin |
Default running cost in your own project
| Resource | US$/month (Google list price, us-central1) |
|---|---|
| GKE Autopilot pod, 2x vCPU / 4 GiB | US$79.35 |
| Cloud SQL for MySQL, 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 | US$149.81 |
How it compares
- Ghost(Pro)'s cheapest paid plan, Starter, is US$18/month (up to 1,000 members, one newsletter, a free custom domain (billed yearly)) — verified at https://ghost.org/pricing/. That undercuts RAD's ~US$149.81/month Google Cloud bill for the GKE variant on sticker price alone, but it caps usage; RAD's instance is uncapped, self-hosted, and the data never leaves your own project.
- The honest trade here is cap vs. control, not price: a managed SaaS plan is cheaper at this scale, and RAD's running cost is what real Cloud SQL, compute and networking actually cost at Google's list price with nothing hidden in a bundled seat price.
- RAD is not claiming to be cheaper than a bare VPS in cash terms — it usually is not. The case for RAD is what's managed for you.
Pause it for free: delete a RAD-managed project, restore it when you need it
If Ghost is running in a RAD-managed project, you can stop paying for it entirely without destroying it. Deleting that project first unlinks its billing, then asks Google to delete the project outright — Google's own 30-day recoverable soft delete. Unlike deleting the Ghost module on its own, 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 build-time credits in total — roughly 5–10 credits, under US$1, for a typical 2–3-deployment chain. The 270-credit module fee is not charged again.
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 have customised Ghost 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
If Ghost is in your own project (or more than 30 days have passed on a RAD-managed one), the way to stop paying is to delete the deployment and redeploy later when you need it again.
A redeploy costs the module fee again, plus the builds: roughly 300 + ~3–6 credits (~US$30.45) in your own project, or 270 + ~3–6 credits on a RAD-managed one.
Deleting only saves money once Ghost would otherwise sit unused long enough to clear that redeploy cost against its own running cost: roughly about 7 days or more idle in your own project (against its ~US$149.81/month Google Cloud bill), or about 3 days or more idle in a RAD-managed project (against its ~115 credits/day).
Most of Ghost's running cost is the database and the shared file/cache VM. They stop only when nothing else in the project uses them, so deleting this app while something else shares the project saves only this app's own compute share of the total above.
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 docs for the pause/restore mechanics; Ghost(Pro) pricing for the Ghost(Pro) figures.
1. Overview
Ghost runs as a Node.js web workload. The deployment wires together a focused set of Google Cloud services:
| Capability | Google Cloud service | Notes |
|---|---|---|
| Compute | GKE Autopilot | Node.js pods, 2 vCPU / 4 GiB by default, horizontally autoscaled |
| Database | Cloud SQL for MySQL 8.0 | Required — Ghost 6.x does not support PostgreSQL |
| Shared files | Filestore (NFS) | Uploaded content and themes shared across all replicas |
| Object storage | Cloud Storage | A dedicated content bucket (ghost-content) provisioned automatically |
| Cache | Redis | Enabled by default; falls back to the NFS host IP when no Redis host is given |
| Secrets | Secret Manager | Database password managed automatically |
| Ingress | Cloud Load Balancing | External LoadBalancer, optional custom domain + managed certificate |
Sensible defaults worth knowing up front:
- MySQL 8.0 is mandatory. Ghost 6.x requires MySQL; PostgreSQL is not supported and will not start.
database__client = "mysql"is injected automatically. Without this Ghost silently falls back to SQLite — the module handles it so you never need to set it manually.- Redis is enabled by default. Ghost uses Redis for page caching to reduce database load and improve response times.
- Session affinity is
ClientIP. Ghost's admin panel and membership portal use server-side sessions; requests from a browser are pinned to one pod. - A
ghost-contentGCS bucket is provisioned automatically byGhost_Commonand does not need to be added tostorage_buckets. - A
db-initjob runs on every apply to idempotently create the Ghost MySQL database and user. - Health probes target
/with a 90-second initial delay to allow Ghost to run database migrations and compile themes on first boot. - The database password is generated automatically and stored in Secret Manager.
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 Ghost workload
Ghost 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 Ghost 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 MySQL 8.0
Ghost stores all application data (posts, members, settings) in a managed Cloud SQL for MySQL 8.0 instance. Pods reach it privately through the Cloud SQL Auth Proxy sidecar over a Unix socket, so no public IP is exposed. On first deploy a db-init Job creates the application database and user.
- 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"
# Open an interactive shell to inspect schema/data:
gcloud sql connect <instance-name> --user=<db-user> --project "$PROJECT"
The instance name, database name, user, and the Secret Manager secret holding the password are all surfaced in the Outputs. For the connection model, automated backups, and password rotation, see App_GKE.
C. Filestore (NFS) and Cloud Storage
Uploaded content (images, themes, files) is written to a Filestore (NFS) share mounted into every pod so all replicas see the same files. A dedicated Cloud Storage bucket (ghost-content) is also provisioned automatically for content; the workload service account is granted access automatically.
- Console: Filestore → Instances for the NFS share; Cloud Storage → Buckets for the content bucket.
- CLI:
gcloud filestore instances list --project "$PROJECT"
gcloud storage buckets list --project "$PROJECT"
gcloud storage ls gs://<content-bucket>/ # bucket name is in the Outputs
# Confirm the share is mounted inside a pod:
kubectl exec -n "$NAMESPACE" deploy/<service-name> -- df -h | grep -i nfs
See App_GKE for NFS provisioning, GCS Fuse, and CMEK options.
D. Redis cache
Redis backs Ghost's page caching. When no external Redis host is configured and NFS is enabled, the NFS host IP is used as the Redis endpoint.
- Console: Memorystore → Redis (if using a managed instance).
- CLI:
redis-cli -h <redis-host> ping # from a host with network access
redis-cli -h <redis-host> info keyspace
# Confirm Redis env vars are set in the Ghost pod:
kubectl exec -n "$NAMESPACE" deploy/<service-name> -- env | grep -i redis
E. Secret Manager
The database password is stored as a Secret Manager secret and injected into pods at runtime; plaintext never appears in configuration.
- Console: Security → Secret Manager.
- CLI:
gcloud secrets list --project "$PROJECT"
gcloud secrets versions access latest --secret=<secret-name> --project "$PROJECT"
The database password secret name is in the Outputs. See App_GKE for the Secret Store CSI integration and rotation.
F. Networking & ingress
The workload is exposed through an external Cloud Load Balancing IP. enable_custom_domain defaults to true, provisioning a Kubernetes Ingress with a Google-managed certificate for the hostnames in application_domains; a static IP is reserved by default (reserve_static_ip = true) so the address survives redeploys.
- Console: Network services → Load balancing; VPC network → IP addresses.
- CLI:
kubectl get ingress,svc -n "$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
3. Ghost Application Behaviour
- First-deploy database setup. A
db-initJob connects to Cloud SQL via the Auth Proxy and idempotently creates the Ghost database (withutf8mb4charset andutf8mb4_0900_ai_cicollation), creates the application user, and grants full privileges. The job runs on every apply and is safe to re-run. - Slow first boot. Ghost runs database migrations and compiles themes on first start. The startup probe allows 90 seconds of initial delay (
initial_delay_seconds = 90,failure_threshold = 10) — do not reduce this below 60 seconds or Ghost will be killed before it finishes initialising. - Dynamic URL detection. The custom entrypoint script queries the Cloud Run/GKE metadata server at startup to discover the service URL and export it as
urlandadmin__urlfor Ghost. An expliciturlenvironment variable always takes precedence. - Database connection. The entrypoint maps the foundation's
DB_HOST,DB_USER,DB_NAME,DB_PASSWORD, andDB_PORTvariables to Ghost'sdatabase__connection__*settings automatically. WhenDB_HOSTstarts with/it is treated as a Unix socket path. - SMTP for email. Ghost requires SMTP for member sign-ups, password resets, and newsletter delivery. Pre-populated
environment_variables(SMTP_HOST,SMTP_PORT,SMTP_USER,SMTP_PASSWORD,SMTP_SSL,EMAIL_FROM) — configure them before inviting members. - Admin login. Ghost's admin panel is at
<url>/ghost. On first boot Ghost creates an admin user interactively. - Health path. Readiness/liveness probes target
/, which returns HTTP 200 when Ghost is fully initialised.
4. Configuration Variables
Variables are grouped exactly as they appear on the deployment platform. Only settings specific to or notable for Ghost 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 | ghost | Base name for resources. Do not change after first deploy. |
application_display_name | Ghost Blog | Friendly name shown in the Console. |
application_description | Ghost Publishing Platform on GKE Autopilot | Workload description annotation. |
application_version | 6.14.0 | Ghost image version tag; increment to roll out a new version. |
Group 4 — Runtime & Scaling
| Variable | Default | Description |
|---|---|---|
deploy_application | true | Set false to provision infrastructure only. |
cpu_limit | 2000m | CPU per pod; 2 vCPU minimum for Ghost 6.x. |
memory_limit | 4Gi | Memory per pod; 4 GiB recommended (Ghost OOMs below 1 GiB). |
min_instance_count | 1 | Minimum replicas. Keep ≥ 1 to avoid cold starts and migration delays. |
max_instance_count | 5 | Maximum replicas (autoscaler ceiling). |
container_port | 2368 | Ghost's native HTTP port. Do not change unless your Dockerfile binds to a different port. |
container_image_source | custom | custom builds via Cloud Build (default); prebuilt deploys an existing image. |
enable_cloudsql_volume | true | Cloud SQL Auth Proxy sidecar for socket connections. Required for Ghost. |
enable_vertical_pod_autoscaling | false | Let Autopilot tune resource requests automatically. |
Group 5 — Environment Variables & Secrets
| Variable | Default | Description |
|---|---|---|
environment_variables | {SMTP_HOST="", SMTP_PORT="587", SMTP_USER="", SMTP_PASSWORD="", SMTP_SSL="false", EMAIL_FROM="ghost@example.com"} | SMTP settings pre-populated for Ghost email delivery. database__client=mysql is injected automatically — do not set it here. |
secret_environment_variables | {} | Map of env var → Secret Manager secret name. |
Group 6 — GKE Backend & Cluster
| Variable | Default | Description |
|---|---|---|
service_type | LoadBalancer | How the Service is exposed. |
session_affinity | ClientIP | Sticky routing required for Ghost admin and membership sessions. |
workload_type | null | Auto-resolves to StatefulSet when per-pod storage is enabled. |
network_tags | ['nfsserver'] | Node/pod tags; nfsserver is required for NFS connectivity. |
Group 7 — StatefulSet
| Variable | Default | Description |
|---|---|---|
stateful_pvc_enabled | null | Enable per-pod PVCs for StatefulSet deployments. |
stateful_pvc_size | 10Gi | Storage per pod. Provision more for active media-heavy publications. |
stateful_pvc_mount_path | /data | Container path for the per-pod PVC. |
stateful_pvc_storage_class | standard-rwo | Kubernetes StorageClass for PVCs. |
Group 8 — Resource Quota
| Variable | Default | Description |
|---|---|---|
enable_resource_quota | false | Cap namespace CPU/memory/object counts. |
quota_memory_requests / quota_memory_limits | "" | Must use binary units (4Gi, 8192Mi) — bare integers are read as bytes and block scheduling. |
Group 9 — Reliability Policies
| Variable | Default | Description |
|---|---|---|
enable_pod_disruption_budget | true | Protect availability during node upgrades. |
pdb_min_available | 1 | Raise min_instance_count above 1 if you need eviction headroom. |
enable_topology_spread | false | Spread pods across zones. |
Group 10 — Observability & Health
| Variable | Default | Description |
|---|---|---|
startup_probe | HTTP / 90s initial delay, 10 failures | HTTP probe against Ghost's root path (200 when ready). Generous delay for first-boot migrations. |
liveness_probe | HTTP / 60s initial delay | Liveness probe targeting Ghost's root path. |
uptime_check_config | disabled | 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 (mysql:8.0-debian). |
cron_jobs | [] | Scheduled Kubernetes CronJobs for Ghost maintenance tasks. |
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 | Shared Filestore volume for Ghost content (keep enabled for multi-replica). |
nfs_mount_path | /mnt/nfs | Mount path inside the container. |
Group 14 — Cloud Storage & Artifact Registry
| Variable | Default | Description |
|---|---|---|
create_cloud_storage | true | Provision the additional bucket from storage_buckets. The ghost-content bucket is always provisioned automatically. |
storage_buckets | [{name_suffix="data"}] | Additional buckets beyond the auto-provisioned content bucket. |
gcs_volumes | [] | GCS Fuse mounts. |
manage_storage_kms_iam / enable_artifact_registry_cmek | false | CMEK options. |
Group 15 — Redis Cache
| Variable | Default | Description |
|---|---|---|
enable_redis | true | Use Redis for Ghost page caching. |
redis_host | "" | Leave empty to use the NFS host IP; set explicitly when NFS is disabled. |
redis_port | 6379 | Redis port. |
redis_auth | "" | Optional Redis auth password (sensitive). |
Group 16 — Database Backend
| Variable | Default | Description |
|---|---|---|
database_type | MYSQL_8_0 | Ghost requires MySQL 8.0 — do not change. |
db_name | ghost | MySQL database name. Immutable after first deploy. |
db_user | ghost | Application user. Immutable after first deploy. |
application_database_name | gkeappdb | Cloud SQL database name (App_GKE variable). Override to ghost for consistency. |
application_database_user | gkeappuser | Cloud SQL user (App_GKE variable). Override to ghost for consistency. |
database_password_length | 32 | Generated password length (16–64). |
enable_auto_password_rotation | false | Zero-downtime DB password rotation. |
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 18 — Custom SQL Scripts
enable_custom_sql_scripts, custom_sql_scripts_bucket, custom_sql_scripts_path, custom_sql_scripts_use_root — run SQL from a GCS bucket after provisioning. See App_GKE.
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. Ghost must know its public URL at startup — ensure the domain matches. |
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 Ghost. |
iap_authorized_users / iap_authorized_groups | [] | Who may access. |
iap_oauth_client_id / iap_oauth_client_secret | "" | Required when IAP is enabled (sensitive). |
iap_support_email | "" | Shown on the OAuth consent screen. |
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. |
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. |
service_external_ip | External LoadBalancer IP (when a static IP is reserved). |
service_url | URL to reach Ghost. |
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 (includes the ghost-content bucket). |
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). |
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).
| Setting | Sensible value | Risk | Consequence if wrong |
|---|---|---|---|
database_type | MYSQL_8_0 | Critical | Ghost requires MySQL 8.0; any other engine breaks startup. |
db_name / db_user | set once | Critical | Immutable after first deploy; renaming recreates the DB/user and destroys all data. |
enable_nfs | true | Critical | Without shared storage, uploaded content is lost on pod restart and not shared across replicas. |
container_port | 2368 | Critical | Ghost's native port; mismatching it causes all health probes to fail. |
enable_backup_import | false unless restoring | Critical | Enabling without a valid backup_uri fails the import job. |
quota_memory_requests / _limits | binary units | Critical | Bare integers are bytes and block all scheduling. |
startup_probe initial_delay_seconds | 90 | High | Reducing below 60 causes Kubernetes to kill Ghost before it finishes running migrations. |
enable_redis | true | High | Without Redis, Ghost serves all pages without a cache, increasing database load. |
redis_host | "" (NFS) or explicit | High | No valid endpoint if Redis is on but NFS is off and no host is set. |
memory_limit | 4Gi | High | Too little memory causes Node.js OOM during newsletter sends or theme compilation. |
session_affinity | ClientIP | High | Without stickiness, multi-replica Ghost admin sessions fail intermittently. |
environment_variables SMTP settings | real SMTP server | High | No email delivery means no member sign-ups, no password resets, no newsletters. |
container_image_source | custom | High | The upstream Ghost image lacks the custom entrypoint that maps DB credentials and detects the service URL. |
min_instance_count | 1 | Medium | 0 causes cold starts during which Ghost runs migrations, making first requests time out. |
enable_iap / enable_cloud_armor | enable for admin-facing | Medium | The Ghost admin panel (/ghost) is otherwise publicly reachable. |
backup_retention_days | 7 (raise for prod) | Medium | Too short for compliance retention. |
pdb_min_available vs min_instance_count | leave headroom | Medium | 1/1 can stall node upgrades (single pod cannot be evicted). |
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. Ghost-specific application configuration shared with the Cloud Run variant is described in Ghost_Common.
Related guides
- Hands-on lab: Ghost on GKE Autopilot — deploy it step by step, with the console screens and commands at each stage.
- Ghost on Google Cloud Run — the same application on Cloud Run, for when you need the other deployment target.
- Ghost Common — Shared Application Configuration — the configuration shared by both deployment targets.
Need RAD to do something it does not do yet? Request it on the roadmap, or vote on what is already there.