Chroma on Google Cloud Run

Chroma is an AI-native open-source vector database purpose-built for embeddings and similarity search. It powers RAG pipelines, semantic search, and LangChain/LlamaIndex workflows. This module deploys Chroma 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 Chroma 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

Chroma runs as a containerised vector-database service on Cloud Run v2. The deployment wires together a focused set of Google Cloud services:

Capability	Google Cloud service	Notes
Compute	Cloud Run v2 (Gen2)	1 vCPU / 1 GiB by default; min_instance_count = 1 to avoid index-reload cold starts
Data persistence	Cloud Storage (GCS FUSE)	Auto-provisioned <prefix>-data bucket mounted at /data; primary storage backend
Auth token	Secret Manager	Optional API token — CHROMA_SERVER_AUTHN_CREDENTIALS injected at runtime
Ingress	Cloud Run internal URL	ingress_settings = "internal" by default; optional HTTPS load balancer + custom domain

Sensible defaults worth knowing up front:

• No SQL database and no Redis. Chroma manages its own embedded storage. No Cloud SQL instance is created and no Redis connection is configured.
• ingress_settings = "internal" by default. The chroma_api_url output is not reachable from the public internet with this setting. Changing to "all" requires enable_auth_token = true (enforced at plan time).
• Single-instance required. max_instance_count = 1 is the default. Multiple Cloud Run instances against the same GCS FUSE mount cannot coordinate writes and will corrupt collections.
• GCS FUSE is the persistence backend. A <prefix>-data bucket is automatically provisioned and mounted at /data. Gen2 execution environment is required.
• Auth token is optional but recommended for any deployment reachable outside the VPC. When enabled, the token is stored in Secret Manager and must be passed as Authorization: Bearer <token> in every API call.
• Health probes are fixed to /api/v2/heartbeat. This is the only health endpoint Chroma exposes; the probe path cannot be changed.
• Anonymised telemetry is always disabled. ANONYMIZED_TELEMETRY=false is injected automatically.

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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 Chroma service

Chroma runs as a Cloud Run v2 service. Each deployment creates an immutable revision; traffic can be split across revisions for safe rollouts. cpu_always_allocated defaults to false (request-based billing); set it true (with `min_instance_count

= 1`) to keep CPU allocated between requests so background index operations and health checks are never throttled.

• 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 Storage (GCS FUSE) — Chroma data persistence

Chroma stores its embedded SQLite database, HNSW index files, and collection metadata at the /data path. A dedicated Cloud Storage bucket (<prefix>-data) is automatically provisioned and mounted at /data via the GCS FUSE CSI driver. The Cloud Run service account is granted read/write access automatically.

• Console: Cloud Storage → Buckets — look for the bucket whose name ends in -data.
• CLI:

  gcloud storage buckets list --project "$PROJECT"
  gcloud storage ls gs://<data-bucket>/chroma/    # inspect Chroma's on-disk layout
  # Confirm the GCS FUSE mount inside a running instance:
  gcloud run services describe <service-name> --region "$REGION" \
    --format='value(spec.template.spec.volumes)'

See App_CloudRun for GCS Fuse, CMEK options, and bucket management.

C. Secret Manager

When enable_auth_token = true, Chroma's API authentication token is generated and stored as a Secret Manager secret. It is injected into the service at runtime as CHROMA_SERVER_AUTHN_CREDENTIALS; plaintext never appears in configuration.

• Console: Security → Secret Manager.
• CLI:

  gcloud secrets list --project "$PROJECT"
  # Retrieve the token to configure API clients:
  gcloud secrets versions access latest --secret=<prefix>-auth-token --project "$PROJECT"

See App_CloudRun for injection and rotation details.

D. Networking & ingress

By default the service is reachable only within the VPC (ingress_settings = "internal"). An external HTTPS load balancer with a custom domain, Cloud CDN, and Cloud Armor can be layered on; egress settings 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"
  # Test the Chroma heartbeat from inside the VPC:
  curl <internal-service-url>/api/v2/heartbeat

See App_CloudRun.

E. Cloud Logging & Monitoring

Container logs flow to Cloud Logging; Cloud Run metrics flow to Cloud Monitoring, with an optional uptime check against /api/v2/heartbeat 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. Chroma Application Behaviour

• No database bootstrap. Chroma manages its own embedded storage and requires no database initialisation job. No db-init job is injected. If you provide custom initialization_jobs, they run as Cloud Run Jobs before the service is updated.
• Index loading on cold start. When a new instance starts (after scale-to-zero or a new revision), it loads HNSW indexes from the GCS bucket. For large collections this can take tens of seconds; the startup probe at /api/v2/heartbeat waits until Chroma signals readiness. Keep min_instance_count = 1 to avoid this on every request.
• Single-instance constraint. Chroma is a single-writer store. Multiple Cloud Run instances against the same GCS FUSE mount will corrupt collections because there is no distributed write lock. Always keep max_instance_count = 1. Scale vertically (increase CPU and memory) rather than horizontally.
• Auth token usage. When enable_auth_token = true, all API calls must include Authorization: Bearer <token>. Retrieve the token from Secret Manager, then use it:

  TOKEN=$(gcloud secrets versions access latest \
    --secret=<prefix>-auth-token --project "$PROJECT")
  curl -H "Authorization: Bearer $TOKEN" <service-url>/api/v2/collections

  Python client:

  import chromadb
  client = chromadb.HttpClient(
      host="<service-hostname>", port=443, ssl=True,
      headers={"Authorization": f"Bearer {TOKEN}"}
  )

• Health probe. Both the startup and liveness probes target /api/v2/heartbeat via HTTP. The probe path is fixed by Chroma_Common and cannot be changed. The startup probe allows 15 seconds initial delay to accommodate GCS FUSE mount and index loading.
• Scheduled tasks. Chroma has no built-in scheduled commands. Use cron_jobs if you need periodic collection snapshots or maintenance tasks, triggered by Cloud Scheduler.

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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 Chroma 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.
enable_auth_token	false	Generate a random API token and store it in Secret Manager. Recommended for any deployment reachable outside the VPC.

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	chroma	Base name for resources. Do not change after first deploy.
application_display_name	Chroma Vector Database	Friendly name shown in the Console.
description	(set)	Cloud Run service description.
application_version	latest	Chroma image version tag. Pin to a specific version for reproducible deployments.

Group 4 — Runtime & Scaling

Variable	Default	Description
deploy_application	true	Set false to provision infrastructure only.
cpu_limit	1000m	CPU per instance; increase to 2000m+ for production query workloads.
memory_limit	1Gi	Memory per instance. Chroma loads HNSW indexes into memory — size based on collection count and vector dimensions.
min_instance_count	1	Minimum instances. Keep ≥ 1 to avoid index-reload cold starts.
max_instance_count	1	Maximum instances. Keep at 1 — multiple instances on the same GCS FUSE path will corrupt collections.
container_port	8000	Chroma REST API port.
execution_environment	gen2	Gen2 required for GCS FUSE mounts.
cpu_always_allocated	false	Request-based billing by default; set true to keep CPU allocated between requests and avoid background index operation timeouts.
timeout_seconds	300	Max request duration. Increase for large batch similarity searches.
enable_cloudsql_volume	false	Not applicable — Chroma has no SQL database.
enable_image_mirroring	true	Mirror the Chroma image into Artifact Registry to avoid Docker Hub rate limits.
traffic_split	[]	Canary/blue-green traffic allocation across revisions.
max_revisions_to_retain	7	Maximum Cloud Run revisions to keep.

Group 5 — Access & Networking

Variable	Default	Description
ingress_settings	internal	Keep internal so Chroma is only reachable within the VPC. Setting all requires enable_auth_token = true (enforced at plan time).
vpc_egress_setting	PRIVATE_RANGES_ONLY	VPC egress mode.
enable_iap	false	Require Google identity authentication via IAP.
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. ANONYMIZED_TELEMETRY=false and CHROMA_SERVER_HTTP_PORT=8000 are always injected.
secret_environment_variables	{}	Map of env var → Secret Manager secret name.
secret_propagation_delay	30	Seconds to wait after secret creation before proceeding.
secret_rotation_period	2592000s	Secret rotation reminder period (30 days).

Group 7 — Backup & Restore

Variable	Default	Description
backup_schedule	0 2 * * *	Automated backup cron (UTC). Leave empty to disable.
backup_retention_days	7	Retention in days. Raise for production/compliance.
enable_backup_import / backup_source / backup_uri / 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, binauthz_evaluation_mode, additional_cloudrun_sa_roles.

Group 9 — Custom SQL Scripts

enable_custom_sql_scripts, custom_sql_scripts_bucket, custom_sql_scripts_path, custom_sql_scripts_use_root — not applicable to Chroma (no SQL database). These variables are accepted for foundation compatibility but have no effect. See App_CloudRun.

Group 10 — Load Balancer, CDN & Artifact Registry

Variable	Default	Description
enable_cloud_armor	false	Provision a Global HTTPS Load Balancer with Cloud Armor WAF.
admin_ip_ranges	[]	CIDRs exempted from WAF rules.
application_domains	[]	Custom domain names for the HTTPS load balancer.
enable_cdn	false	Enable Cloud CDN on the HTTPS load balancer. Requires enable_cloud_armor = true.
max_images_to_retain / delete_untagged_images / image_retention_days	(set)	Artifact Registry cleanup policy.

Group 11 — Storage & Filesystem

Variable	Default	Description
create_cloud_storage	true	Provision GCS buckets. The <prefix>-data bucket is provisioned automatically by Chroma_Common.
storage_buckets / gcs_volumes	(set)	Additional buckets / GCS FUSE mounts.
enable_nfs	false	Mount Cloud Filestore NFS (requires gen2). Chroma uses GCS for primary storage; enable only for custom init jobs.
nfs_mount_path	/mnt/nfs	NFS container mount path.
manage_storage_kms_iam / enable_artifact_registry_cmek	false	CMEK options.

Group 12 — Database Backend

Not applicable — Chroma has no SQL database. The following variables are accepted for foundation compatibility only and are fixed or ignored: database_type (fixed to NONE), database_password_length, enable_auto_password_rotation, rotation_propagation_delay_sec, db_host_env_var_name, db_user_env_var_name, db_name_env_var_name, db_port_env_var_name, service_url_env_var_name.

Group 13 — Jobs & Scheduled Tasks

Variable	Default	Description
initialization_jobs	[]	Chroma requires no default init job. Provide jobs for custom data loading only.
cron_jobs	[]	Recurring Cloud Scheduler-triggered jobs (e.g., collection snapshots).

Group 14 — Observability & Health

Variable	Default	Description
startup_probe / startup_probe_config	/api/v2/heartbeat	HTTP startup probe — Chroma returns 200 once fully initialised. Probe path is fixed.
liveness_probe / health_check_config	/api/v2/heartbeat	Liveness probe.
uptime_check_config	enabled=false, path=/api/v2/heartbeat	Cloud Monitoring uptime check; disabled by default.
alert_policies	[]	Metric alert policies.

Group 23 — 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.
chroma_api_url	Internal VPC URL for the Chroma v2 API (append /collections, /heartbeat, etc.). Only reachable within the VPC when ingress_settings is internal.
service_location	Region the service runs in.
stage_services	Stage-specific service details (Cloud Deploy).
storage_buckets	Created Cloud Storage buckets.
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 custom 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
enable_auth_token	true for any externally reachable deployment	Critical	Without a token any caller who can reach the Chroma API can read, write, or delete every collection.
ingress_settings	internal (default)	High	Changing to "all" without enable_auth_token = true exposes an unauthenticated vector database to the public internet (blocked at plan time).
max_instance_count	1	High	Multiple instances against the same GCS FUSE path will corrupt collections — Chroma has no distributed write lock.
execution_environment	gen2	High	GCS FUSE requires Gen2. Deploying with gen1 while GCS volumes are configured fails the deployment.
memory_limit	4Gi+ for production	High	Chroma loads HNSW indexes into memory. The default 1Gi supports only very small collections; OOM kills drop in-flight queries.
cpu_always_allocated	true	Medium	Setting false causes CPU throttling between requests, slowing index operations and potentially causing health check timeouts.
application_version	pin to a specific tag	Medium	Using latest makes deployments non-reproducible. Chroma data formats can change across major versions.
timeout_seconds	increase for large collections	Medium	Large similarity searches over millions of vectors can take several seconds; 504s return to clients if the timeout is too low.
min_instance_count	1	Medium	Scale-to-zero causes cold starts during which HNSW indexes must be reloaded from GCS, adding latency for the first request after idle.
enable_iap / enable_cloud_armor	enable for externally reachable services	High	Without authentication, an externally exposed Chroma endpoint is fully open.
backup_retention_days	raise for production	Medium	Regular GCS bucket snapshots are the primary recovery path; too-short retention limits recovery options.
enable_cloudsql_volume	false	Low	Chroma has no SQL database; enabling this injects a Cloud SQL Auth Proxy sidecar that consumes resources unnecessarily.

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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. Chroma-specific application configuration shared with the GKE variant is described in Chroma_Common.