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ClassicPress on Cloud Run — Lab Guide

📖 Configuration Guide

Overview​

Estimated time: 45–90 minutes

ClassicPress is a free, open-source, business-focused CMS — a lightweight fork of WordPress 4.9.x that preserves the classic (pre-Gutenberg) editing experience, with plugins, themes, a media library, and a REST API. This lab takes you through the full operational lifecycle of the ClassicPress on Cloud Run 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 Cloud Run module and the Google Cloud platform, not on ClassicPress 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.
  • Access the running service and complete the first-run ClassicPress installer.
  • Perform day-2 operations — inspect, scale, update, and manage secrets and backups.
  • Recognise and work around the confirmed media-persistence limitation on Cloud Run.
  • Observe the service with Cloud Logging and Cloud Monitoring.
  • Diagnose and resolve the most common deployment and runtime issues.
  • Tear the deployment down cleanly.

Prerequisites​

  • Services_GCP deployed in the target project (provides the VPC, Cloud SQL, Artifact Registry, and shared service accounts this module depends on).
  • A Google Cloud project with billing enabled.
  • gcloud CLI authenticated: gcloud auth login and gcloud auth application-default login.
  • Project Owner (or equivalent) IAM on the project.
  • 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

Task 1 — Deploy the module [Automated]​

  1. In the RAD platform, open ClassicPress (Cloud Run), set project_id, and review the inputs. Configure only what you need — the Configuration Guide documents every input by group, with defaults. Review the estimated cost (if credits are enabled) and click Deploy, which opens the deployment status page with real-time logs.

  2. The platform builds a thin custom image (FROM classicpress/classicpress) via Cloud Build, provisions the Cloud Run service, a Cloud SQL for MySQL 8.0 database with its Secret Manager secrets (CLASSICPRESS_SALT_SEED and the database password), a Filestore (NFS) instance (enable_nfs = true by default), two Cloud Storage buckets (data and classicpress-uploads), and runs a one-shot database-initialisation job (db-init) that creates the application database and user. First deploys take roughly 15–30 minutes (Cloud SQL and Filestore creation dominate).

  3. When it completes, discover the resources with name-agnostic filters (so the commands keep working regardless of the deployment suffix):

    SERVICE=$(gcloud run services list --project="$PROJECT" --region="$REGION" \
      --filter="metadata.name~classicpress" --format="value(metadata.name)" --limit=1)
    SERVICE_URL=$(gcloud run services describe "$SERVICE" \
      --project="$PROJECT" --region="$REGION" --format="value(status.url)")
    echo "Service: $SERVICE"
    echo "URL:     $SERVICE_URL"

Task 2 — Access & verify [Manual]​

  1. Confirm the service is up. ClassicPress has no dedicated health endpoint before installation, so a simple reachability check is the right first probe:

    curl -s -o /dev/null -w "%{http_code}\n" "$SERVICE_URL/"
    # expect 200 (already installed) or 302 (redirect to the first-run installer)

  2. Open $SERVICE_URL in a browser. On a fresh database, ClassicPress redirects to /wp-admin/install.php — complete the installer (site title, admin username, password, and email) to create the schema and the admin account. There is no pre-seeded admin credential in Secret Manager; the installer is the only way to set one.

  3. Log in at $SERVICE_URL/wp-login.php with the account you just created and confirm the dashboard loads.

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

  1. Inspect the service and its revisions (each deploy creates an immutable revision; traffic shifts to the newest healthy one):

    gcloud run services describe "$SERVICE" --project="$PROJECT" --region="$REGION"
    gcloud run revisions list --service="$SERVICE" --project="$PROJECT" --region="$REGION"

  2. Scale by changing the min/max instance inputs and clicking Update on the deployment details page — the module owns the service spec, so scaling is a configuration change, not a manual gcloud edit (a manual edit would be reverted on the next apply). Keep max_instance_count = 1: the ClassicPress install lives on the container's own filesystem, which is per-instance and not shared, so a second concurrent instance would run its own diverging copy of the site.

  3. Update the application version by changing the version input in the RAD platform and applying it via Update; a new image builds and a new revision rolls out.

  4. Manage secrets and backups:

    gcloud secrets list --project="$PROJECT" --filter="name~classicpress"
    gcloud run jobs list --project="$PROJECT" --region="$REGION"   # db-init + scheduled backup jobs

  5. Open a database session for inspection or maintenance:

    INSTANCE=$(gcloud sql instances list --project="$PROJECT" --format="value(name)" --limit=1)
    gcloud sql connect "$INSTANCE" --user=classicpress --project="$PROJECT"

  6. Known limitation — uploaded media and plugins do not survive a cold start. This module defaults to min_instance_count = 0 (scale-to-zero), but neither the ClassicPress_Common Dockerfile nor its entrypoint.sh ever mount storage under /var/www/html — the directory where ClassicPress's own entrypoint writes wp-config.php and copies the whole application, including wp-content/uploads and any plugin/theme installed through wp-admin. enable_nfs = true is on by default, but it mounts Filestore at /var/lib/classicpress, a path the image never reads or writes. The two GCS buckets the module provisions (data and classicpress-uploads) are likewise not wired in as a gcs_volumes mount out of the box. Practical effect: every time the service scales to zero and a new instance cold-starts (idle timeout, redeploy, instance replacement), /var/www/html starts empty again — uploaded media and admin-installed plugins/themes from the previous instance are gone. The Cloud SQL database (pages, posts, settings, and the media metadata rows) is unaffected and survives. This is confirmed by direct inspection of the Dockerfile and entrypoint, not a theoretical risk.

    Two practical workarounds, in order of effort:

    • Set min_instance_count = 1. This keeps one instance warm permanently, so /var/www/html is never re-initialised from empty during normal operation (it still resets on every redeploy/version update, since that always creates a fresh instance). This is the quickest fix and is recommended for any real use of ClassicPress's media library or plugin installs.
    • Add a gcs_volumes mount at /var/www/html/wp-content/uploads pointing at the classicpress-uploads bucket, so uploads specifically survive instance churn (this does not cover plugins/themes installed elsewhere under /var/www/html).
    • Use ClassicPress_GKE instead if you need the whole install (code, plugins, themes, uploads) to persist by default — the GKE variant mounts a StatefulSet block PVC at /var/www/html at the Application-module level, which is unaffected by this Common-layer gap because the PVC happens to cover the exact directory the entrypoint populates.

Task 4 — Observe: Logging & Monitoring [Manual]​

  1. Logs — from the CLI or the Logs Explorer:

    gcloud run services logs read "$SERVICE" --project="$PROJECT" --region="$REGION" --limit=50

    Logs Explorer filter: resource.type="cloud_run_revision" AND resource.labels.service_name="<service>".

  2. Monitoring — open the Cloud Run dashboard for the service and review request count, request latency (P50/P95/P99), instance count (scaling behaviour), and CPU / memory utilisation. uptime_check_config is disabled (enabled = false) by default for this module — enable it in the platform if you want a Monitoring uptime check and check-failure alert wired up.

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 ClassicPress releases.

  • Uploaded files or installed plugins disappearing after an idle period (KNOWN BUG): this is the confirmed /var/www/html persistence gap described in Task 3 — enable_nfs = true is the default but mounts Filestore at /var/lib/classicpress, a path the image never touches, so scale-to-zero (min_instance_count = 0, the default) silently wipes media/plugins on the next cold start while the database (posts, settings, metadata) stays intact. Confirm by comparing wp-content/uploads file counts before and after an idle period long enough to trigger scale-to-zero, or by checking that revision/instance identity changed: 
    gcloud run revisions list --service="$SERVICE" --project="$PROJECT" --region="$REGION"
    Fix: set min_instance_count = 1, add a gcs_volumes mount for wp-content/uploads, or move to ClassicPress_GKE (StatefulSet PVC at /var/www/html). This is not a misconfiguration you can "fix" by changing an env var — it is a gap in the current Common-layer entrypoint.
  • Revision unhealthy / service won't serve: inspect the latest revision and its logs for startup errors, and confirm env vars and secrets resolved. The startup probe is TCP on port 80 with a generous failure_threshold = 20, giving the upstream entrypoint time to populate /var/www/html on first boot. 
    gcloud run revisions list --service="$SERVICE" --project="$PROJECT" --region="$REGION"
    gcloud run services logs read "$SERVICE" --project="$PROJECT" --region="$REGION" --limit=100
  • Site stuck on the first-run installer after you thought you'd completed it: this is the same underlying bug — if the instance that ran the installer was never made durable (see Task 3), a fresh cold-started instance's wp-config.php is gone even though the database schema it created is still there; ClassicPress falls back to a confusing partial state. Re-running the installer against an already-populated database is not safe — apply the min_instance_count = 1 workaround first, then redo the install cleanly.
  • Database connection errors: confirm the Cloud SQL instance is RUNNABLE and the db-init job completed successfully. MySQL is reached over private-IP TCP by default (enable_cloudsql_volume = false); no SSL configuration is required.
  • Initialisation job failed: list executions and read the failed one's logs: 
    gcloud run jobs executions list --job="${SERVICE}-db-init" \
      --project="$PROJECT" --region="$REGION"
  • Image build failed: review Cloud Build history for the failed build's log.
  • 403 / permission errors: verify the runtime service account's IAM roles.

See the Configuration Guide's Configuration Pitfalls & Sensible Defaults section for setting-specific gotchas (including the critical rule never to rotate CLASSICPRESS_SALT_SEED after first boot, and the full detail behind the media-persistence bug above).

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 — it removes the deployment from RAD's records without destroying the cloud resources (it makes RAD forget the project). This removes everything the module created — the Cloud Run service, Cloud SQL database, Secret Manager secrets, Filestore instance, GCS buckets, and Artifact Registry images. Resources owned by Services_GCP (the VPC, shared Cloud SQL, registry) are managed separately and are not removed here.

Summary​

TaskTypeOutcome
1 — DeployAutomatedModule provisions Cloud Run, Cloud SQL (MySQL 8.0), Filestore, secrets, storage buckets, and runs db-init
2 — Access & verifyManualReachability check passes; complete the first-run installer to create the admin account
3 — OperateManualInspect revisions, scale, update version, manage secrets/backups, DB access; understand the media-persistence bug and its workarounds
4 — ObserveManualQuery Cloud Logging; review Cloud Monitoring metrics
5 — TroubleshootManualDiagnose revision, database, init-job, build, and IAM issues; recognise the confirmed uploads/plugins cold-start data-loss bug
6 — Tear downAutomatedDelete (Trash) removes all module resources

By · Google Cloud certified: ACE · PCA · PCD · PDE · PSE · CDL

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