Castopod on Cloud Run — Lab Guide

Overview

Estimated time: 45–90 minutes

Castopod is an open-source, ActivityPub-native podcast hosting platform built on CodeIgniter 4 (PHP 8) and served by FrankenPHP/Caddy. This lab takes you through the full operational lifecycle of the Castopod 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 Castopod 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 and verify the running service and complete Castopod's install wizard.
Perform day-2 operations — inspect, scale, update, and manage secrets, media, and backups.
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, Filestore NFS, 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]

Click Deploy in the RAD platform top navigation, open Castopod (Cloud Run) from the Platform Modules list to start configuration, 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.
The platform provisions the Cloud Run service (FrankenPHP/Caddy on port 8080), a Cloud SQL (MySQL 8.0) database with its Secret Manager secrets (DB password plus the auto-generated CP_ANALYTICS_SALT), a media GCS bucket, an NFS share for durable episode audio and artwork, builds the custom container image (a thin build on the upstream castopod/castopod image that grafts the platform entrypoint), and runs a one-shot database-initialisation job. First deploys take roughly 20–35 minutes (Cloud SQL creation dominates).

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="$REGION" \
  --filter="metadata.name~castopod" --format="value(metadata.name)" --limit=1)
SERVICE_URL=$(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]

Confirm the service is healthy. Castopod's unauthenticated homepage / returns HTTP 200 once the app has booted and connected to MySQL — CodeIgniter runs its schema migrations on first start, so allow a few minutes on a fresh deploy:
```
curl -s -o /dev/null -w "%{http_code}\n" "$SERVICE_URL/"
```
Open $SERVICE_URL in a browser and complete Castopod's web install wizard — create the first super-admin account and set the instance name and podcast defaults. The base URL is derived automatically from the runtime service URL, so feed and media links point at the right host. The database password (in Secret Manager) can be retrieved if needed:
```
DB_SECRET=$(gcloud secrets list --project="$PROJECT" \
  --filter="name~castopod" --format="value(name)" --limit=1)
gcloud secrets versions access latest --secret="$DB_SECRET" --project="$PROJECT"
```
Upload a short test episode (audio + artwork) and confirm the public RSS feed renders. Public feeds and media downloads are why ingress_settings = "all" is the default — don't restrict it (or add IAP) on a public podcast instance.

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

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"

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). The default is scale-to-zero (min = 0) with max = 1; keep max_instance_count = 1 unless the shared media filesystem and cache are confirmed multi-instance-safe.
Update the application version by changing the version input via Update on the deployment details page; a new image builds and a new revision rolls out, applying any pending CodeIgniter migrations on its first start.

Manage secrets, media storage, and jobs:

gcloud secrets list --project="$PROJECT" --filter="name~castopod"
gcloud run jobs list --project="$PROJECT" --region="$REGION"   # db-init job
gcloud storage buckets list --project="$PROJECT" --filter="name~media"
gcloud filestore instances list --project="$PROJECT"           # NFS for media

Keep CP_ANALYTICS_SALT stable — it anonymises listener analytics, and changing it breaks de-duplication continuity for previously recorded listeners.

Open a database session for inspection or maintenance:

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

Task 4 — Observe: Logging & Monitoring [Manual]

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>".
Monitoring — open the Cloud Run dashboard for the service and review request count, request latency (P50/P95/P99), instance count (scaling behaviour, including scale-to-zero periods), and CPU / memory utilisation. Feed fetches from podcast apps show up as steady background request traffic. Review Monitoring → Uptime checks and Alerting → Policies for the provisioned checks.

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 Castopod releases.

Revision unhealthy / service won't serve: the startup probe is TCP with a retry window that covers first-boot CodeIgniter migrations; the liveness probe hits /. Inspect the latest revision and its logs before concluding the service failed:
```
gcloud run revisions list --service="$SERVICE" --project="$PROJECT" --region="$REGION"
gcloud run services logs read "$SERVICE" --project="$PROJECT" --region="$REGION" --limit=100
```
Database connection errors: confirm the Cloud SQL (MySQL 8.0) instance is RUNNABLE, the DB password secret exists, and the db-init job completed. Note Castopod connects over the private-IP TCP address (CodeIgniter's mysqli driver cannot use the Auth Proxy socket directory) — the entrypoint resolves this automatically.

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"

Uploads vanish after a restart: verify enable_nfs = true and the Filestore instance is healthy — with NFS off, episode audio and artwork live on ephemeral disk and are lost on every restart or redeploy.
Image build failed: review Cloud Build history for the failed build's log. The image is a custom build on castopod/castopod that grafts the entrypoint which writes the DB config into Castopod's .env — the upstream image alone cannot consume the injected credentials.
Broken feed or media links: the entrypoint derives the base URL from the runtime service URL; if you moved to a custom domain, redeploy so feeds pick up the new host.
403 / permission errors: verify the runtime service account's IAM roles; if IAP was enabled, remember it blocks all unauthenticated access — including public RSS feeds and media downloads.

See the Configuration Guide's Configuration Pitfalls section for setting-specific gotchas.

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 (podcasts, episodes, users, analytics), Secret Manager secrets (including CP_ANALYTICS_SALT), the media GCS bucket, the NFS share holding uploaded audio and artwork, and Artifact Registry images. Resources owned by Services_GCP (the VPC, shared Cloud SQL, registry) are managed separately and are not removed here.

Summary

Task	Type	Outcome
1 — Deploy	Automated	Module provisions Cloud Run, Cloud SQL (MySQL 8.0), NFS, media bucket, secrets, builds the image, and runs DB init
2 — Access & verify	Manual	Homepage returns 200; complete the install wizard; upload a test episode and check the feed
3 — Operate	Manual	Inspect revisions, scale, update version, manage secrets/media/backups, DB access
4 — Observe	Manual	Query Cloud Logging; review Cloud Monitoring metrics and uptime checks
5 — Troubleshoot	Manual	Diagnose revision, database, init-job, NFS-media, build, base-URL, and IAM issues
6 — Tear down	Automated	Delete (Trash) removes all module resources

By Dr Shiyghan Emmanuel Navti · Google Cloud certified: ACE · PCA · PCD · PDE · PSE · CDL

Overview​

Objectives​

Prerequisites​

Task 1 — Deploy the module [Automated]​

Task 2 — Access & verify [Manual]​

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

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

Task 5 — Troubleshoot & debug [Manual]​

Task 6 — Tear down [Automated]​

Summary​