LangFlow on Google Cloud Run

LangFlow is an open-source, low-code visual builder for AI agents and workflows, built on LangChain — you assemble language-model chains, RAG pipelines, and agents by dragging and wiring components on a canvas, then expose them as APIs. This module deploys LangFlow 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 LangFlow 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.

---

1. Overview

LangFlow runs as a single Python (FastAPI + React) 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	Python service on port 7860, 1 vCPU / 2 GiB by default, serverless autoscaling; scale-to-zero supported
Database	Cloud SQL for PostgreSQL 15	Required — LangFlow persists all flows, components, and credentials in Postgres
Object storage	Cloud Storage	A data bucket is provisioned by default (storage_buckets) but left unmounted (gcs_volumes = []) — LangFlow keeps all application state in PostgreSQL
Cache & queue	Redis (optional)	Not required by LangFlow; wired for forward compatibility only
Secrets	Secret Manager	Auto-generated LANGFLOW_SECRET_KEY and LANGFLOW_SUPERUSER_PASSWORD; database password
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 mandatory. The database engine is fixed by the shared application layer (database_type = "POSTGRES_15"); selecting any other engine breaks startup.
• LANGFLOW_SECRET_KEY is generated automatically and stored in Secret Manager. It encrypts every stored credential embedded in a flow. It must never be rotated after first boot — rotating it permanently breaks all stored credentials, which then have to be re-entered in each flow.
• The admin account is provisioned from a generated password. LANGFLOW_AUTO_LOGIN = "false" turns on authentication; LangFlow creates the initial admin (admin by default) using the LANGFLOW_SUPERUSER_PASSWORD secret. Retrieve it from Secret Manager to log in.
• Scale-to-zero is enabled by default (min_instance_count = 0). Cold starts add several seconds of latency — plus first-boot Alembic migrations on a fresh instance. Set min_instance_count = 1 to keep the canvas warm for interactive editing.
• max_instance_count = 1 by default. LangFlow keeps in-process session and flow state; run a single instance unless you have externalised state and understand the implications.
• Public ingress by default. ingress_settings = "all" exposes the run.app URL. Enabling IAP places Google sign-in in front of the whole service, including its API.
• No NFS, and the default GCS bucket is unmounted. All application state lives in PostgreSQL; NFS is off by default, and the auto-provisioned data bucket is not mounted into the container (gcs_volumes = []) — it exists for you to wire up only if a custom component needs object storage.
• LANGFLOW_DATABASE_URL is composed at runtime by the container entrypoint from the injected DB_* variables (TCP DSN, sslmode=require on Cloud Run) — you do not set it yourself.

---

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 LangFlow service

LangFlow 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" \
    --filter="metadata.name~langflow"
  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

LangFlow stores all application data (flows, components, credentials, run history, users) in a managed Cloud SQL for PostgreSQL 15 instance. The service connects privately over the instance private IP (the entrypoint composes a TCP DSN with sslmode=require); the Cloud SQL Auth Proxy Unix socket is also mounted. On first deploy an initialization Job creates the application database, role, and grants.

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

  gcloud sql instances list --project "$PROJECT" --filter="name~langflow"
  gcloud sql instances describe <instance-name> --project "$PROJECT"
  gcloud sql connect <instance-name> --user=<db-user> --database=<db-name> --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. Redis (optional — not used by LangFlow)

Redis is disabled by default and LangFlow does not require it; the enable_redis inputs are wired for forward compatibility only. Leave enable_redis = false unless a future feature needs it.

• CLI (only if enabled):

  gcloud run services describe <service-name> --region "$REGION" \
    --format='value(spec.template.spec.containers[0].env)'

D. Secret Manager

Two secrets are generated automatically and stored in Secret Manager: LANGFLOW_SECRET_KEY (encrypts all stored credentials) and LANGFLOW_SUPERUSER_PASSWORD (the initial admin login password). The database password is managed separately by the foundation.

• Console: Security → Secret Manager.
• CLI:

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

See App_CloudRun for injection and rotation details.

E. 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; ingress settings and VPC egress control connectivity.

• 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.

F. 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

---

3. LangFlow Application Behaviour

• First-deploy database setup. An initialization Job (db-init) runs the Foundation's generic db-init.sh script using postgres:15-alpine. It waits for PostgreSQL, then idempotently creates the application role and database, sets ownership, and grants privileges on the database. It is safe to re-run.
• Schema migrations on start. LangFlow runs its Alembic migrations on every container start, so the tables are created and upgraded by the application itself — the db-init job only handles role/database/grants. Allow extra time on first boot.
• LANGFLOW_SECRET_KEY is immutable after first boot. It is generated once and written to Secret Manager. Changing it permanently breaks every stored credential embedded in a flow; they can no longer be decrypted. Only rotate during a planned maintenance window with a plan to re-enter credentials.
• Initial admin account. With LANGFLOW_AUTO_LOGIN = "false", LangFlow creates the superuser (admin by default, set via langflow_username) using the LANGFLOW_SUPERUSER_PASSWORD secret. Retrieve the password and log in:

  gcloud secrets versions access latest \
    --secret=<langflow-password-secret> --project "$PROJECT"

• Database URL is composed at runtime. The entrypoint builds LANGFLOW_DATABASE_URL from the injected DB_* vars over TCP (DB_IP, sslmode=require on Cloud Run) — do not set it manually unless you intend to override the whole DSN.
• Health path. Startup and liveness probes target /health, LangFlow's public liveness endpoint that returns 200 once the server is up. The default startup probe allows a 60-second initial delay plus a 60 × 10s (600s) failure window to cover first-boot component loading and Alembic migrations.
• Inspect job execution:

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

---

4. Configuration Variables

Variables are grouped exactly as they appear on the deployment platform. Only settings specific to or notable for LangFlow 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.

All other inputs follow standard App_CloudRun behaviour.

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.

All other inputs follow standard App_CloudRun behaviour.

Group 3 — Application Identity

Variable	Default	Description
application_name	langflow	Base name for resources. Do not change after first deploy.
application_display_name	LangFlow	Human-readable name shown in the Console.
application_version	latest	LangFlow image version tag; pins base image 1.10.2 when latest. Pin explicitly in production.
langflow_username	admin	Initial superuser (admin) username; the password is auto-generated in Secret Manager.

All other inputs follow standard App_CloudRun behaviour.

Group 4 — Runtime & Scaling

Variable	Default	Description
deploy_application	true	Set false to provision infrastructure only.
container_image_source	custom	LangFlow is built from the wrapped image via Cloud Build.
cpu_limit	1000m	CPU per instance.
memory_limit	2Gi	Memory per instance; keep ≥ 1 GiB for the Python runtime.
min_instance_count	0	0 enables scale-to-zero; set 1 to keep the canvas warm.
max_instance_count	1	Keep at 1 — LangFlow holds in-process state.
container_port	7860	LangFlow listens on port 7860.
execution_environment	gen2	Gen2 required for NFS/GCS Fuse mounts.
timeout_seconds	300	Maximum request duration (0–3600 seconds).
enable_cloudsql_volume	true	Cloud SQL Auth Proxy socket mount.
enable_image_mirroring	true	Mirrors the container image into Artifact Registry before deployment.

All other inputs follow standard App_CloudRun behaviour.

Group 5 — Access & Networking

Variable	Default	Description
ingress_settings	all	all exposes the public run.app URL.
vpc_egress_setting	PRIVATE_RANGES_ONLY	Route only RFC 1918 traffic via VPC.
enable_iap	false	Require Google sign-in in front of the whole service.
iap_authorized_users / iap_authorized_groups	[]	Who may access through IAP.

All other inputs follow standard App_CloudRun behaviour.

Group 6 — Environment Variables & Secrets

Variable	Default	Description
environment_variables	{}	Extra non-secret settings merged over the LangFlow defaults. Do not set LANGFLOW_SECRET_KEY, LANGFLOW_SUPERUSER_PASSWORD, or LANGFLOW_DATABASE_URL here.
secret_environment_variables	{}	Map of env var → Secret Manager secret name (e.g. LLM provider API keys).
secret_propagation_delay	30	Seconds to wait after secret creation before proceeding.
secret_rotation_period	2592000s	Secret Manager rotation notification frequency.

All other inputs follow standard App_CloudRun behaviour.

Group 7 — Backup & Maintenance

Variable	Default	Description
backup_schedule	0 2 * * *	Automated Cloud SQL 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.

All other inputs follow standard App_CloudRun behaviour.

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 & Initialization

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 — Load Balancer, CDN & Image Retention

Variable	Default	Description
enable_cloud_armor	false	Provision Global HTTPS LB + Cloud Armor WAF.
admin_ip_ranges	[]	CIDR ranges exempted from WAF rules.
application_domains	[]	Custom domain names for the HTTPS LB.
enable_cdn	false	Enable Cloud CDN on the HTTPS LB backend.
max_images_to_retain / delete_untagged_images / image_retention_days	(set)	Artifact Registry cleanup policy.

All other inputs follow standard App_CloudRun behaviour.

Group 11 — Storage & Filesystem

Variable	Default	Description
create_cloud_storage	true	Create GCS buckets defined in storage_buckets.
storage_buckets	[{ name_suffix = "data" }]	One data bucket is declared by default; extend the list for custom components.
enable_nfs	false	NFS is off by default; LangFlow keeps state in PostgreSQL.
nfs_mount_path	/mnt/nfs	Mount path inside the container (when NFS is enabled).
gcs_volumes	[]	GCS Fuse volume mounts (requires gen2).
manage_storage_kms_iam / enable_artifact_registry_cmek	false	CMEK options.

All other inputs follow standard App_CloudRun behaviour.

Group 12 — Database Backend

Variable	Default	Description
database_type	POSTGRES_15	Fixed — LangFlow requires PostgreSQL 15.
application_database_name	langflowdb	PostgreSQL database name. Immutable after first deploy.
application_database_user	langflowuser	Application database user. Password auto-generated in Secret Manager.
database_password_length	32	Generated password length.
enable_postgres_extensions / postgres_extensions	off	Optional Postgres extensions.
enable_auto_password_rotation / rotation_propagation_delay_sec	off	DB password rotation.

All other inputs follow standard App_CloudRun behaviour.

Group 13 — Jobs & Scheduled Tasks

Variable	Default	Description
initialization_jobs	[{ name = "db-init", image = "postgres:15-alpine", script_path = "scripts/db-init.sh", execute_on_apply = true }]	Built-in job that creates the application role, database, and grants on first deploy. Override with a non-empty list to run different jobs.
cron_jobs	[]	Scheduled Cloud Run jobs (none required by LangFlow).
additional_services	[]	Sidecar/helper services deployed alongside LangFlow.

All other inputs follow standard App_CloudRun behaviour.

Group 14 — Observability & Health

Variable	Default	Description
startup_probe	HTTP /health, 60s delay, 60 × 10s failure window	Startup probe. The generous 600s window past the 60s delay accounts for LangFlow's first boot (loading all components + seeding starter projects before uvicorn binds — 2–4 minutes) as well as first-boot Alembic migrations.
liveness_probe	HTTP /health, 30s delay	Liveness probe.
startup_probe_config	HTTP /health, enabled	App_CloudRun-level structured probe (parallel to startup_probe, which is passed to LangFlow_Common).
health_check_config	HTTP /health, enabled	App_CloudRun-level structured liveness probe (parallel to liveness_probe).
uptime_check_config	disabled	Cloud Monitoring uptime check; enable for production monitoring.
alert_policies	[]	Metric alert policies.

All other inputs follow standard App_CloudRun behaviour.

Group 21 — Redis Cache (optional)

Variable	Default	Description
enable_redis	false	Not used by LangFlow; wired for forward compatibility only.
redis_host / redis_port / redis_auth	"" / 6379 / ""	Redis connection settings (only if enabled).

All other inputs follow standard App_CloudRun behaviour.

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.

All other inputs follow standard App_CloudRun behaviour.

---

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 (a data bucket 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 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.

---

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, a database_type that does not match an enabled extension, an out-of-range redis_port/backup_retention_days, and more. 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
LANGFLOW_SECRET_KEY (auto-generated)	Never rotate after first boot	Critical	Rotating it permanently breaks every stored credential embedded in a flow — they cannot be decrypted and must be re-entered.
application_database_name / application_database_user	Set once	Critical	Immutable after first deploy; renaming recreates the DB/user and destroys all flows and credentials.
database_type	POSTGRES_15	Critical	LangFlow requires PostgreSQL 15; any other engine breaks startup.
enable_backup_import	false unless restoring	Critical	Enabling without a valid backup source fails the import job.
LANGFLOW_SUPERUSER_PASSWORD (auto-generated)	Retrieve from Secret Manager	High	This is the admin login; losing it means no way to sign in until it is reset.
memory_limit	2Gi	High	Values below 1 GiB risk OOM kills for the Python runtime under load.
max_instance_count	1	High	LangFlow keeps in-process session/flow state; scaling beyond 1 splits state across instances and causes inconsistent behaviour.
enable_iap	only when API auth not needed externally	High	IAP puts Google sign-in in front of the whole service, including its programmatic API.
container_port	7860	High	LangFlow listens on 7860; a mismatched port fails all health probes.
min_instance_count	1 for interactive use	Medium	Scale-to-zero (0) adds cold-start latency plus first-boot migration time on a fresh instance.
enable_cloudsql_volume	true	Medium	Disabling removes the socket mount; the entrypoint then relies solely on the private-IP TCP path.
backup_retention_days	7 (raise for prod)	Medium	Too short for compliance retention.
enable_cloud_armor	enable for production	Medium	The UI and API are publicly reachable without WAF protection.

---

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 building — see App_CloudRun. LangFlow-specific application configuration shared with the GKE variant is described in LangFlow_Common.