Ntfy on Google Cloud Run

ntfy is an open-source, Apache 2.0-licensed pub/sub push-notification server written in Go. Applications publish messages over a simple REST/HTTP API and clients receive them instantly over WebSocket or Server-Sent-Events (SSE) streams — no external database required. This module deploys ntfy on Cloud Run v2 on top of the App_CloudRun foundation, which provisions and manages the shared Google Cloud infrastructure.

This guide focuses on the cloud services ntfy uses and how to explore and operate them from the Google Cloud Console and the command line. For the mechanics common to every Cloud Run application — service identity, ingress and load balancing, scaling and concurrency, CI/CD, Cloud Armor, IAP, Binary Authorization, VPC Service Controls, backups, and the deployment lifecycle — refer to the App_CloudRun foundation guide rather than repeating them here.

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1. Overview

ntfy runs as a single Go container on Cloud Run v2. The deployment wires together a deliberately small set of Google Cloud services — ntfy has no database, cache, or object-storage dependency of its own:

Capability	Google Cloud service	Notes
Compute	Cloud Run v2	Single Go service, 1 vCPU / 512 MiB by default; CPU always allocated for long-lived streams
Database	None	database_type = "NONE"; message cache is a local SQLite file, no Cloud SQL provisioned
Persistence	Ephemeral disk (default) or NFS (optional)	SQLite cache at /var/cache/ntfy/cache.db; enable NFS for durable message history
Object storage	None	ntfy stores nothing in Cloud Storage
Cache / queue	None	No Redis; ntfy uses an in-process message bus
Secrets	Secret Manager	No auto-generated secrets; only user-supplied secret_environment_variables
Ingress	Cloud Run URL / Cloud Load Balancing	Default run.app URL; optional external HTTPS load balancer + custom domain

Sensible defaults worth knowing up front:

• No database is provisioned. database_type = "NONE" — ntfy keeps its message cache in a local SQLite file. The database-related variables exist for completeness but are inert unless you deliberately opt in to an external database.
• The message cache is ephemeral by default. It lives at /var/cache/ntfy/cache.db. Cloud Run's root filesystem is read-only, so the entrypoint falls back to /tmp/ntfy when the configured directory is not writable. Message history is therefore lost on each restart/redeploy unless you enable NFS (enable_nfs = true) and point the cache directory at the mount.
• CPU is always allocated (cpu_always_allocated = true). ntfy holds long-lived WebSocket/SSE streams open to push messages to connected subscribers in real time, so CPU must not be throttled between requests. Flipping this to false saves cost on a low-traffic instance but pauses real-time delivery while idle.
• Single instance by default (min_instance_count = 1, max_instance_count = 1). Because a subscriber's stream is anchored to the instance that holds it and there is no shared message bus, scaling out is not the default. Keep max at 1 unless you place a shared cache/broker behind ntfy.
• Public ingress is the default (ingress_settings = "all") so publishers and subscribers can reach the service. Enabling IAP requires Google sign-in and blocks unauthenticated publish/subscribe calls.
• The health endpoint is /v1/health, which returns {"healthy":true} with HTTP 200 as soon as the server binds its port.
• Access control is a post-deploy step. ntfy ships with open access; configure users and topic ACLs afterwards via its CLI or NTFY_AUTH_* environment variables.

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2. Google Cloud Services & How to Explore Them

All commands assume PROJECT and REGION are set. Service and resource names are reported in the deployment Outputs.

A. Cloud Run — the ntfy service

ntfy runs as a Cloud Run v2 service. Each deployment creates an immutable revision; traffic can be split across revisions for safe rollouts. Because CPU is always allocated, an active instance keeps its subscriber streams alive between requests.

• Console: Cloud Run → select the service for revisions, traffic, logs, and metrics.
• CLI:

  gcloud run services list --project "$PROJECT" --region "$REGION"
  gcloud run services describe <service-name> --project "$PROJECT" --region "$REGION"
  gcloud run revisions list --service <service-name> --project "$PROJECT" --region "$REGION"

See App_CloudRun for scaling, concurrency, execution environment, and traffic splitting.

B. Persistence — the SQLite message cache

ntfy has no Cloud SQL instance. Its message cache is a local SQLite file at NTFY_CACHE_FILE (/var/cache/ntfy/cache.db), created by the entrypoint on boot. On Cloud Run's read-only root filesystem the entrypoint falls back to /tmp/ntfy when that path is not writable — so with the default configuration the cache is ephemeral and message history does not survive a restart.

For durable history, enable NFS and mount it where the cache lives:

• Console: Filestore → Instances (when enable_nfs = true).
• CLI:

  # Confirm the cache path injected into the running revision:
  gcloud run services describe <service-name> --project "$PROJECT" --region "$REGION" \
    --format='value(spec.template.spec.containers[0].env)'

See App_CloudRun for the NFS (Filestore) mount model.

C. Secret Manager

ntfy generates no secrets at deploy time — there is no database password or encryption key to manage. Secret Manager is used only if you supply your own via secret_environment_variables (for example an NTFY_AUTH_* value or an upstream push credential).

• Console: Security → Secret Manager.
• CLI:

  gcloud secrets list --project "$PROJECT"
  gcloud secrets versions access latest --secret=<secret-name> --project "$PROJECT"

See App_CloudRun for injection and rotation details.

D. Networking & ingress

The service is reachable at its run.app URL by default, which allows the public access ntfy needs for publish/subscribe traffic. An external HTTPS load balancer with a custom domain, Cloud CDN, and Cloud Armor can be layered on; ingress settings and VPC egress control connectivity. If clients use HTTP/2 streaming, set container_protocol = "h2c".

• Console: Cloud Run (service URL); Network services → Load balancing.
• CLI:

  gcloud run services describe <service-name> --region "$REGION" --format='value(status.url)'
  gcloud compute addresses list --project "$PROJECT"

See App_CloudRun.

E. Cloud Logging & Monitoring

Container logs flow to Cloud Logging; Cloud Run metrics flow to Cloud Monitoring, with optional uptime checks and alert policies. ntfy logs its listen address and resolved cache path on startup.

• Console: Logging → Logs Explorer; Monitoring → Dashboards / Alerting.
• CLI:

  gcloud run services logs read <service-name> --project "$PROJECT" --region "$REGION" --limit 50

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3. Ntfy Application Behaviour

• No first-deploy database setup. ntfy has no external database and no migration step. The entrypoint prepares the SQLite cache directory and immediately execs ntfy serve. There is no db-init job by default.
• Ephemeral cache with automatic fallback. The entrypoint creates NTFY_CACHE_FILE's directory; on Cloud Run's read-only rootfs it falls back to /tmp/ntfy and logs a warning. This keeps a baseline (NFS-less) deploy healthy. Enable NFS for durable message history.
• Real-time delivery needs allocated CPU. Subscribers hold open WebSocket/SSE streams; cpu_always_allocated = true ensures the in-process message bus keeps delivering between inbound requests.
• Health path. Startup and liveness probes target /v1/health, which returns {"healthy":true} and HTTP 200 as soon as the server binds port 80. Verify:

  SERVICE_URL=$(gcloud run services describe <service-name> \
    --project "$PROJECT" --region "$REGION" --format='value(status.url)')
  curl -s "$SERVICE_URL/v1/health"      # -> {"healthy":true}

• Publish / subscribe smoke test.

  curl -d "hello from ntfy" "$SERVICE_URL/mytopic"     # publish
  curl -s "$SERVICE_URL/mytopic/json"                   # subscribe (streaming JSON)

• Access is open until you lock it down. By default any client can publish to and subscribe from any topic. Configure users and per-topic ACLs post-deploy via ntfy's CLI (ntfy user add, ntfy access) or the NTFY_AUTH_* environment variables.
• Public base URL for attachments / web push. If you use attachments or browser web-push, set NTFY_BASE_URL (via environment_variables) to the service's public URL so generated links resolve correctly.

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4. Configuration Variables

Variables are grouped exactly as they appear on the deployment platform. Only settings specific to or notable for ntfy are listed; every other input is inherited from App_CloudRun with its standard behaviour.

Group 1 — Project & Identity

Variable	Default	Description
project_id	(required)	Target Google Cloud project.
region	us-central1	Region for the service and regional resources.

Group 2 / 3 — Deployment Environment & Application Identity

Variable	Default	Description
tenant_deployment_id	demo	Short suffix that makes resource names unique per environment.
application_name	ntfy	Base name for the service, registry repo, and secrets. Do not change after first deploy.
application_display_name	Ntfy	Human-readable name shown in the Console.
application_version	latest	Image version tag; latest maps to a pinned v2.11.0 base. Pin an explicit v2.x.y in production.

Group 4 — Runtime & Scaling

Variable	Default	Description
deploy_application	true	Set false to provision supporting infrastructure only.
container_image_source	custom	custom builds the wrapper image via Cloud Build; prebuilt deploys an image directly.
cpu_limit	1000m	CPU per instance.
memory_limit	512Mi	Memory per instance (gen2 floor is 512Mi).
min_instance_count	1	Minimum instances.
max_instance_count	1	Keep at 1 — streams are instance-local with no shared broker.
container_port	80	ntfy listens on port 80.
container_protocol	http1	Set h2c for end-to-end HTTP/2 streaming.
cpu_always_allocated	true	Required for real-time stream delivery; flip to false only for low-traffic cost savings.
enable_cloudsql_volume	false	Off — ntfy has no database.
enable_image_mirroring	true	Mirror the ntfy image into Artifact Registry.

Group 5 — Access & Networking

Variable	Default	Description
ingress_settings	all	all is required for public publish/subscribe traffic.
enable_iap	false	Require Google sign-in. Blocks unauthenticated publish/subscribe.

Group 6 — Environment Variables & Secrets

Variable	Default	Description
environment_variables	{}	Extra NTFY_* settings (e.g. NTFY_BASE_URL, NTFY_AUTH_DEFAULT_ACCESS).
secret_environment_variables	{}	Map of env var → Secret Manager secret name (optional; none required).

Group 11 — Storage & Filesystem

Variable	Default	Description
enable_nfs	false	Enable to back the SQLite cache with NFS for durable message history.
nfs_mount_path	/mnt/nfs	NFS mount path; point NTFY_CACHE_FILE at it for persistence.
storage_buckets	[]	Not required — ntfy uses no object storage.

Group 12 — Database Backend

Variable	Default	Description
database_type	NONE	ntfy has no external database; leave NONE.
application_database_name / application_database_user	ntfy	Inert unless an external database is deliberately enabled.

Group 13 — Jobs & Scheduled Tasks

Variable	Default	Description
initialization_jobs	[]	ntfy needs no init job; leave empty.
cron_jobs	[]	Optional scheduled Cloud Run jobs.

Group 14 — Observability & Health

Variable	Default	Description
startup_probe	HTTP /v1/health 30s delay	Startup probe. ntfy becomes healthy within seconds.
liveness_probe	HTTP /v1/health 30s delay	Liveness probe.
uptime_check_config	{ enabled=false, path="/v1/health" }	Optional Cloud Monitoring uptime check.

Group 16 — Redis Cache

Variable	Default	Description
enable_redis	false	Not required — ntfy has no Redis dependency.

All other inputs follow standard App_CloudRun behaviour.

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5. Outputs

Returned on a successful deployment — the quickest way to locate and explore the running resources.

Output	Description
service_name	Cloud Run service name.
service_url	Default run.app URL of the service.
service_location	Region the service runs in.
stage_services	Stage-specific service URLs (Cloud Deploy).
load_balancer_ip / load_balancer_url	External HTTPS load balancer IP / URL (when enabled).
database_instance_name / database_name / database_user	Database identifiers — empty for the default NONE engine.
database_password_secret / database_host / database_port	Database endpoint fields — unused for NONE.
storage_buckets	Created Cloud Storage buckets (none by default).
network_name / network_exists / regions	VPC network, presence, regions.
container_image / container_registry	Deployed image and Artifact Registry repo.
monitoring_enabled / monitoring_notification_channels / uptime_check_names	Monitoring status, channels, uptime checks.
initialization_jobs	Names of any setup jobs (none by default).
deployment_id / tenant_id / resource_prefix	Naming identifiers.
project_id / project_number	Project identifiers.
cicd_enabled / github_repository_url / github_repository_owner / github_repository_name / cicd_configuration	CI/CD status and details.
artifact_registry_repository / cloudbuild_trigger_name / cloudbuild_trigger_id	Registry and build trigger.
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.

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6. Configuration Pitfalls & Sensible Defaults

Risk: Critical (data loss / outage / security) — High (service degraded) — Medium (cost or partial degradation) — Low (minor).

Inherited plan-time validation. This module passes its configuration through the App_CloudRun foundation engine, which validates values and combinations at plan time — IAP with no authorized identities, a gen1 runtime with NFS/GCS mounts, an out-of-range container_port/timeout_seconds, a memory value below the gen2 floor. Invalid configuration fails the plan with a clear, named error before any resource is created, so most mistakes below are caught up front rather than at apply or runtime.

Setting	Sensible value	Risk	Consequence if wrong
enable_nfs (for durable history)	true when history matters	High	With the default ephemeral cache, all message history is lost on every restart/redeploy — acceptable for a pure relay, surprising if you expected persistence.
max_instance_count	1	High	Scaling beyond 1 splits subscribers across instances with no shared bus, so a message published to one instance is not delivered to subscribers pinned to another.
cpu_always_allocated	true	High	Setting false lets Cloud Run throttle CPU between requests, pausing real-time WebSocket/SSE delivery while the instance is idle.
ingress_settings	all	High	internal blocks external publishers and subscribers from reaching the service.
enable_iap	only when auth-gated	High	IAP requires Google sign-in for every request, blocking unauthenticated publish/subscribe — usually not what a notification endpoint wants.
NTFY_BASE_URL	Actual service URL	Medium	Unset, attachment and web-push links resolve to the wrong host.
ntfy access control	Configure post-deploy	Medium	Left default, any client can publish to and subscribe from any topic on a public URL.
container_protocol	http1 (or h2c)	Medium	Mismatch with clients that require HTTP/2 streaming degrades or breaks long-lived streams.
memory_limit	512Mi	Low	The gen2 execution environment rejects values below 512Mi at apply time.
application_version	Pin v2.x.y in prod	Low	latest maps to a pinned base (v2.11.0); pin explicitly to control upgrades.

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For the foundation behaviour referenced throughout — service identity, scaling and concurrency, ingress and load balancing, CI/CD, Cloud Armor, IAP, Binary Authorization, VPC-SC, backups, and image mirroring — see App_CloudRun. ntfy-specific application configuration shared with the GKE variant is described in Ntfy_Common.