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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.
  • Confirm how the default NFS mount achieves upload/plugin/theme persistence on Cloud Run, and know the residual caveats around it.
  • 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 (provides the VPC, Cloud SQL, 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 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: wp-content (uploads, plugins, themes) is shared across instances via the NFS mount, but ClassicPress's core files outside wp-content are copied independently by each instance on boot, and concurrent-write safety on the shared wp-content mount across multiple replicas has not been validated for this module.

  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)
    # Role and database are tenant-prefixed (e.g. classicpressdemo426161cf) — not the bare app name.
    DB_USER=$(gcloud sql users list --instance="$INSTANCE" --project="$PROJECT" \
      --format="value(name)" --filter="name~^classicpress" --limit=1)
    gcloud sql connect "$INSTANCE" --user="$DB_USER" --project="$PROJECT"

  6. Uploaded media, plugins, and themes persist across cold starts by default. This module defaults to min_instance_count = 0 (scale-to-zero) and enable_nfs = true, which mounts Filestore at /var/www/html/wp-content — the directory where ClassicPress (a WordPress fork) reads and writes uploaded media, installed plugins, and themes. The upstream entrypoint's first-boot copy logic explicitly skips an existing wp-content directory rather than overwriting it, so mounting NFS there is what keeps that content durable across instance churn (idle timeout, redeploy, instance replacement). Only the ClassicPress core files outside wp-content are freshly copied into /var/www/html on each cold start — expected, since those files ship with the image and need no persistence. You can confirm this yourself: upload a media file, trigger a cold start (wait past the idle timeout, or force a new revision), and verify the file is still present.

    Two residual caveats worth knowing:

    • The two GCS buckets the module provisions (data and classicpress-uploads) are not wired in as a gcs_volumes mount by default. They exist but are unused unless you add a gcs_volumes entry — NFS is the persistence path that is actually active out of the box, not these buckets.
    • max_instance_count stays at 1 by default. wp-content is shared across instances via NFS, but concurrent-write safety across multiple simultaneous replicas writing to that shared mount has not been validated for this module — see item 2 above.

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 appear to disappear after an idle period: with the default enable_nfs = true, wp-content (uploads, plugins, themes) is mounted on Filestore at /var/www/html/wp-content and should survive scale-to-zero cold starts — the upstream entrypoint's copy logic skips that directory rather than overwriting it. If content genuinely disappears, first confirm enable_nfs wasn't disabled and that the Filestore instance is READY (gcloud filestore instances list --project="$PROJECT") rather than assuming persistence is broken by design. Compare wp-content/uploads file counts before and after an idle period long enough to trigger scale-to-zero, or check that revision/instance identity changed: 
    gcloud run revisions list --service="$SERVICE" --project="$PROJECT" --region="$REGION"
  • 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: wp-config.php and the ClassicPress core files are recreated fresh on every cold start (expected — they ship with the image), while the database and wp-content (via NFS) persist. If the installer appears to run again, check that the database schema was actually written on the prior attempt — db-init only creates the empty database and user; the installer itself must complete successfully to create the schema and admin account. Re-running the installer against an already-populated database is not safe; verify the schema state first with gcloud sql connect before retrying.
  • 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 NFS-backed persistence mechanism 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; confirm NFS-backed upload/plugin/theme persistence across cold starts
4 — ObserveManualQuery Cloud Logging; review Cloud Monitoring metrics
5 — TroubleshootManualDiagnose revision, database, init-job, build, and IAM issues; verify NFS-backed uploads/plugins persistence across cold starts
6 — Tear downAutomatedDelete (Trash) removes all module resources

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

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