Zammad on Google Cloud Run

Zammad is an open-source helpdesk and customer support platform — a GDPR-compliant alternative to Zendesk and Freshdesk. This module deploys Zammad 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 Zammad 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

Zammad runs as a Ruby on Rails (railsserver) container on Cloud Run v2. The deployment wires together a focused set of Google Cloud services:

Capability	Google Cloud service	Notes
Compute	Cloud Run v2	Rails service, 2 vCPU / 4 GiB by default, request-based autoscaling
Database	Cloud SQL for PostgreSQL 15	Required — Zammad does not support MySQL
Attachment storage	Filestore (NFS)	Ticket attachments at /opt/zammad/storage, shared across all instances
Object storage	Cloud Storage	A dedicated zammad-attachments bucket, always provisioned
Cache & job queue	Redis	Enabled by default; required for ActionCable WebSocket pub/sub and Sidekiq
Secrets	Secret Manager	Database password managed automatically
Ingress	Cloud Run URL / Cloud Load Balancing	Default run.app URL, optional external HTTPS load balancer + custom domain

Sensible defaults worth knowing up front:

• PostgreSQL 15 is required. MySQL is not supported and is rejected at plan time.
• Redis is required. Zammad uses Redis for real-time ticket updates (ActionCable) and background job processing (Sidekiq). Without it, Zammad fails to start.
• A custom image is built via Cloud Build. container_image_source = "custom" is the default — Cloud Build wraps the official zammad/zammad Docker Hub image with a GCP-specific entrypoint.sh that maps Foundation DB_* variables to Zammad's POSTGRESQL_* convention.
• The startup probe targets /. Zammad returns HTTP 200 there only once fully initialised. The probe is deliberately lenient (30 failure threshold) to accommodate first-boot schema migration.
• Database migrations run on every instance start (idempotent via zammad-init), so version upgrades apply schema changes automatically.
• min_instance_count = 0 is the default (scale-to-zero); override to 1 to eliminate 60–90-second cold starts on a production helpdesk.

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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 Zammad service

Zammad runs as a Cloud Run v2 service that autoscales by request load between the minimum and maximum instance counts. Each deployment creates an immutable revision; traffic can be split across revisions for safe rollouts.

• 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. Cloud SQL for PostgreSQL 15

Zammad stores all helpdesk data (tickets, users, channels, SLA records) in a managed Cloud SQL for PostgreSQL 15 instance. The service connects privately through the Cloud SQL Auth Proxy over a Unix socket — no public IP is exposed. On the first deploy an initialization Job creates the application database and user. On every subsequent instance start, zammad-init applies any pending schema migrations.

Cloud Run TCP workaround: Zammad's docker-entrypoint.sh checks PostgreSQL readiness using a TCP bash socket. Because Cloud Run's DB_HOST is a Unix socket path (not TCP-addressable), the custom entrypoint.sh uses the Cloud SQL private IP (DB_IP) instead for this check.

• Console: SQL → select the instance for connections, backups, flags, metrics.
• CLI:

  gcloud sql instances list --project "$PROJECT"
  gcloud sql instances describe <instance-name> --project "$PROJECT"
  gcloud sql connect <instance-name> --user=<db-user> --project "$PROJECT"

The instance name, database, user, and password secret are in the Outputs. See App_CloudRun for the connection model, backups, and password rotation.

C. Filestore (NFS) and Cloud Storage

Ticket attachments and uploaded files are written to a Filestore (NFS) share mounted at /opt/zammad/storage inside the service so all instances share the same files. A dedicated Cloud Storage (zammad-attachments) bucket is also provisioned automatically. Gen2 execution environment is required for NFS mounts.

• Console: Filestore → Instances; Cloud Storage → Buckets.
• CLI:

  gcloud filestore instances list --project "$PROJECT"
  gcloud storage buckets list --project "$PROJECT"
  gcloud storage ls gs://<attachments-bucket>/    # bucket name is in the Outputs

See App_CloudRun for the NFS mount, GCS Fuse, and CMEK.

D. Redis cache and job queue

Redis is mandatory for Zammad and serves two critical roles:

1. ActionCable pub/sub — delivers real-time ticket updates to agents across multiple Cloud Run instances.
2. Sidekiq — processes background jobs (email dispatch, SLA notifications, LDAP sync, scheduler tasks).

When no external redis_host is configured and NFS is enabled, the NFS host IP is used as the Redis endpoint. For production, use a dedicated Google Cloud Memorystore for Redis instance and set vpc_egress_setting = "ALL_TRAFFIC" so Cloud Run can reach its private IP.

• Console: Memorystore → Redis (if using a managed instance).
• CLI:

  redis-cli -h <redis-host> ping
  redis-cli -h <redis-host> info keyspace

E. Secret Manager

The database password is stored in Secret Manager and injected into the service at runtime. Zammad manages its own internal signing keys — no application-level secret is auto-generated by this module.

• 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.

F. Networking & ingress

The service is reachable at its run.app URL by default. An external HTTPS load balancer with a custom domain, Cloud CDN, and Cloud Armor can be layered on. When using Memorystore for Redis, vpc_egress_setting must be "ALL_TRAFFIC" so Redis connections are routed through the VPC.

• 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.

G. Cloud Logging & Monitoring

Container logs flow to Cloud Logging; Cloud Run and Cloud SQL metrics flow to Cloud Monitoring, with optional uptime checks and alert policies.

• 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. Zammad Application Behaviour

• First-deploy database setup. An initialization Job (db-init) runs before the service starts. It connects to Cloud SQL via the Auth Proxy and idempotently creates the Zammad database, user, and grants privileges. It is safe to re-run.
• Migrations on every start. The custom entrypoint.sh calls zammad-init (Rails DB migration + seed) before starting the railsserver on every instance start. Pending migrations are applied; already-run ones are skipped.
• Variable bridging. The Foundation module injects database credentials as DB_HOST, DB_USER, DB_PASSWORD, etc. The custom entrypoint.sh maps these to Zammad's POSTGRESQL_* convention, and uses DB_IP (Cloud SQL private IP) for the TCP readiness check because Cloud Run's DB_HOST is a Unix socket path.
• WebSocket connectivity. Zammad agents receive live ticket updates via ActionCable WebSockets. With multiple instances, Redis pub/sub coordinates events across them — this is why enable_redis = true is mandatory.
• Health path. Startup and liveness probes target /, which returns HTTP 200 only when Zammad is fully initialised. The startup probe allows up to 510 seconds total (60-second initial delay, 30 retries at 15-second intervals) to accommodate first-boot schema migration.
• Email integration. Configure SMTP after first login at Admin → Channels → Email. SMTP credentials can be injected via secret_environment_variables.
• Inspect scheduled jobs:

  gcloud run jobs list --project "$PROJECT" --region "$REGION"
  gcloud run jobs executions list --job <job-name> --project "$PROJECT" --region "$REGION"

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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 Zammad 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.
elasticsearch_url	""	Elasticsearch HTTP endpoint for full-text search. Leave empty to disable.
elasticsearch_username	""	Elasticsearch username. Leave empty when security is disabled.

Group 2 — Deployment Environment

Variable	Default	Description
tenant_deployment_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.

Group 3 — Application Identity

Variable	Default	Description
application_name	zammad	Base name for resources. Do not change after first deploy.
display_name	Zammad Helpdesk	Friendly name shown in the Console.
description	(set)	Service description.
application_version	6.4.1	Zammad image version tag; increment to trigger a new build.

Group 4 — Runtime & Scaling

Variable	Default	Description
deploy_application	true	Set false to provision infrastructure only.
container_image_source	custom	custom builds via Cloud Build (required for the GCP entrypoint); prebuilt skips the build.
container_image	""	Override container image URI. Leave empty for Cloud Build to manage.
cpu_limit	2000m	CPU per instance. 2 vCPU minimum for Zammad.
memory_limit	4Gi	Memory per instance. Minimum 2 GiB; 4 GiB recommended.
container_port	3000	Zammad railsserver port. Must match ZAMMAD_RAILSSERVER_PORT.
execution_environment	gen2	Gen2 required for NFS mounts and GCS Fuse.
min_instance_count	0	Minimum instances (scale-to-zero). Set ≥ 1 to avoid cold starts on a production helpdesk.
max_instance_count	5	Maximum instances (cost ceiling).
enable_cloudsql_volume	true	Cloud SQL Auth Proxy for socket connections. Do not disable.
enable_image_mirroring	true	Mirrors the Zammad Docker Hub image into Artifact Registry before deploy.
traffic_split	[]	Split traffic across revisions for staged rollouts.
max_revisions_to_retain	7	How many old revisions to keep.

Group 5 — Access & Ingress Control

Variable	Default	Description
ingress_settings	all	Which networks may reach the service (all / internal / internal-and-cloud-load-balancing).
vpc_egress_setting	PRIVATE_RANGES_ONLY	Use ALL_TRAFFIC when Redis is hosted on Memorystore (private IP).
enable_iap	false	Require Google sign-in via Identity-Aware Proxy.
iap_authorized_users / iap_authorized_groups	[]	Who may access through IAP.

Group 6 — Environment Variables & Secrets

Variable	Default	Description
environment_variables	{}	Extra non-secret settings. Core POSTGRESQL_* and RAILS_* values are set automatically.
secret_environment_variables	{}	Map of env var → Secret Manager secret name (e.g. for SMTP passwords).
explicit_secret_values	{}	Sensitive values to store and inject as secrets.
secret_propagation_delay	30	Seconds to wait after secret creation before proceeding.
secret_rotation_period	2592000s	Secret Manager rotation notification frequency.

Group 7 — Backup & Restore

Variable	Default	Description
backup_schedule	0 2 * * *	Automated backup cron (UTC).
backup_retention_days	7	Retention; raise for production/compliance.
enable_backup_import / backup_source / backup_file / backup_format	restore options	Restore from a backup on deploy.

Group 8 — CI/CD & Binary Authorization

Standard App_CloudRun Cloud Build / Cloud Deploy integration — see App_CloudRun. Key inputs: enable_cicd_trigger, github_repository_url, github_token, enable_cloud_deploy, enable_binary_authorization.

Group 9 — 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_CloudRun.

Group 10 — Domain, CDN, Cloud Armor & Image Retention

Variable	Default	Description
application_domains	[]	Custom hostnames for the external load balancer.
enable_cdn	false	Enable Cloud CDN on the LB backend (suitable only for static assets).
enable_cloud_armor / admin_ip_ranges	off	Attach a WAF policy / restrict privileged access.
max_images_to_retain / delete_untagged_images / image_retention_days	(set)	Artifact Registry cleanup policy.

Group 11 — Storage & Filesystem

Variable	Default	Description
enable_nfs	true	Shared Filestore volume for Zammad attachment storage. Requires Gen2.
nfs_mount_path	/opt/zammad/storage	Mount path inside the container. Must match Zammad's storage configuration.
create_cloud_storage / storage_buckets / gcs_volumes	(set)	Additional buckets / GCS Fuse mounts. The zammad-attachments bucket is always created.
manage_storage_kms_iam / enable_artifact_registry_cmek	false	CMEK options.

Group 12 — Database Backend

Variable	Default	Description
database_type	POSTGRES_15	Fixed — do not change. Zammad requires PostgreSQL.
db_name	zammad	Database name. Immutable after first deploy.
db_user	zammad	Application user. Immutable after first deploy.
database_password_length	32	Generated password length (16–64).
enable_auto_password_rotation / rotation_propagation_delay_sec	off	DB password rotation.

Group 13 — Jobs & Scheduled Tasks

Variable	Default	Description
initialization_jobs	[]	Leave empty to use the built-in db-init job. Non-empty list replaces it entirely.
cron_jobs	[]	Recurring jobs triggered by Cloud Scheduler. Zammad handles its own internal scheduling; add custom maintenance jobs here.

Group 14 — Observability & Health

Variable	Default	Description
startup_probe / startup_probe_config	/, 60s delay, 30 retries	Generous tolerance for first-boot schema migration.
liveness_probe / health_check_config	/, 60s delay	Restarts the container after 3 consecutive failures.
uptime_check_config	disabled	Cloud Monitoring uptime check targeting /; set enabled = true to provision it.
alert_policies	[]	Metric alert policies.

Group 21 — Redis Cache & Job Queue

Variable	Default	Description
enable_redis	true	Required. Use Redis for ActionCable and Sidekiq.
redis_host	""	Leave empty to use the NFS host IP; set explicitly for Memorystore.
redis_port	6379	Redis port.
redis_auth	""	Optional Redis auth password (sensitive).

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.

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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	Cloud SQL instance name.
database_name / database_user	Application database name / user.
database_password_secret	Secret Manager secret holding the DB password.
database_host / database_port	DB endpoint / port.
storage_buckets	Created Cloud Storage buckets (including zammad-attachments).
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 the setup jobs.
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).

Setting	Sensible value	Risk	Consequence if wrong
database_type	POSTGRES_15	Critical	Zammad requires PostgreSQL; MySQL is rejected at plan time.
container_image_source	custom (default)	Critical	Using prebuilt without the custom entrypoint means DB_* → POSTGRESQL_* mapping does not happen and all database connections fail on startup.
enable_cloudsql_volume	true	Critical	Disabling removes the Auth Proxy socket; all database connections fail.
db_name / db_user	set once	Critical	Immutable after first deploy; renaming recreates the DB/user and destroys all helpdesk data.
enable_backup_import	false unless restoring	Critical	Enabling without a valid backup fails the import job; enabling on every apply overwrites live data.
enable_redis	true	Critical	Without Redis, ActionCable and Sidekiq fail to initialise; Zammad will not start.
redis_host	explicit or NFS IP	Critical	Empty with NFS disabled means no valid Redis endpoint — Zammad fails to start.
memory_limit	4Gi	High	Zammad OOMs during schema migration or under load below 2 GiB.
nfs_mount_path	/opt/zammad/storage	High	Changing this causes attachments to be written to ephemeral instance storage; existing NFS attachments become inaccessible.
enable_nfs	true	High	Without NFS, all uploaded attachments are lost on instance restart.
min_instance_count	1	High	0 causes 60–90-second cold starts for the first agent to open a ticket.
vpc_egress_setting	ALL_TRAFFIC when using Memorystore	High	Memorystore Redis private IP may not be reachable with PRIVATE_RANGES_ONLY; Redis connections are refused.
startup_probe.initial_delay_seconds	60 (or higher)	High	Too short causes restart loops while schema migration is running on first boot.
max_instance_count > 1 without Redis	configure Redis first	Medium	Multiple instances without Redis cause race conditions on ticket assignment and real-time state divergence.
enable_iap / enable_cloud_armor	enable for admin-facing	Medium	The Zammad admin UI is otherwise publicly reachable.
backup_retention_days	7 (raise for prod)	Medium	Too short for compliance retention.
enable_cdn	off (default)	Medium	Zammad's API responses are dynamic; CDN caching breaks ticket lists and real-time views unless Cache-Control: no-cache headers are set.

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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. Zammad-specific application configuration shared with the GKE variant is described in Zammad_Common.