buun-stack/trino/README.md

Trino

Fast distributed SQL query engine for big data analytics with Keycloak authentication.

Overview

This module deploys Trino using the official Helm chart with:

• Keycloak OAuth2 authentication for Web UI access
• Password authentication for JDBC clients (Metabase, etc.)
• PostgreSQL catalog for querying PostgreSQL databases
• Iceberg catalog with Lakekeeper (optional)
• TPCH catalog with sample data for testing

Prerequisites

• Kubernetes cluster (k3s)
• Keycloak installed and configured
• PostgreSQL cluster (CloudNativePG)
• MinIO (optional, for Iceberg catalog)
• External Secrets Operator (optional, for Vault integration)

Installation

Basic Installation

just trino::install

You will be prompted for:

1. Trino host (FQDN): e.g., trino.example.com
2. PostgreSQL catalog setup: Recommended for production use
3. MinIO storage setup: Optional, for Iceberg/Hive catalogs

What Gets Installed

• Trino coordinator (1 instance)
• Trino workers (2 instances by default)
• OAuth2 client in Keycloak
• Password authentication for JDBC access
• PostgreSQL catalog (if selected)
• Iceberg catalog with Lakekeeper (if MinIO selected)
  • Keycloak service account enabled for OAuth2 client credentials flow
  • lakekeeper client scope added
  • lakekeeper audience mapper configured
• TPCH catalog with sample data

Configuration

Environment variables (set in .env.local or override):

TRINO_NAMESPACE=trino                   # Kubernetes namespace
TRINO_CHART_VERSION=1.41.0              # Helm chart version
TRINO_IMAGE_TAG=477                     # Trino version
TRINO_COORDINATOR_MEMORY=4Gi            # Coordinator memory
TRINO_COORDINATOR_CPU=2                 # Coordinator CPU
TRINO_WORKER_MEMORY=4Gi                 # Worker memory
TRINO_WORKER_CPU=2                      # Worker CPU
TRINO_WORKER_COUNT=2                    # Number of workers

Usage

Web UI Access

1. Navigate to https://your-trino-host/
2. Click "Sign in" to authenticate with Keycloak
3. Execute queries in the Web UI

Get Admin Password

For JDBC/Metabase connections:

just trino::admin-password

Returns the password for username admin.

Metabase Integration

Important: Trino requires TLS/SSL for password authentication. You must use the external hostname (not the internal Kubernetes service name).

1. In Metabase, go to Admin → Databases → Add database

2. Select Database type: Starburst

3. Configure connection:

   Host: your-trino-host (e.g., trino.example.com)
   Port: 443
   Username: admin
   Password: [from just trino::admin-password]
   Catalog: postgresql  (or iceberg for Iceberg tables)
   SSL: Yes
   

Catalog Selection:

• Use postgresql to query PostgreSQL database tables
• Use iceberg to query Iceberg tables via Lakekeeper
• You can create multiple Metabase connections, one for each catalog

Note: Do NOT use internal Kubernetes hostnames like trino.trino.svc.cluster.local as they do not have valid TLS certificates for password authentication.

Example Queries

Query TPCH sample data:

SELECT * FROM tpch.tiny.customer LIMIT 10;

Query PostgreSQL:

SELECT * FROM postgresql.public.pg_tables;

Query Iceberg tables:

-- Show schemas in Iceberg catalog
SHOW SCHEMAS FROM iceberg;

-- Show tables in a namespace
SHOW TABLES FROM iceberg.ecommerce;

-- Query Iceberg table
SELECT * FROM iceberg.ecommerce.products LIMIT 10;

Show all catalogs:

SHOW CATALOGS;

Show schemas in a catalog:

SHOW SCHEMAS FROM postgresql;
SHOW SCHEMAS FROM iceberg;

Catalogs

TPCH (Always Available)

Sample TPC-H benchmark data for testing:

• tpch.tiny.* - Small dataset
• tpch.sf1.* - 1GB dataset

Tables: customer, orders, lineitem, part, supplier, nation, region

PostgreSQL

Queries your CloudNativePG cluster:

• Catalog: postgresql
• Default schema: public
• Database: trino

Iceberg (Optional)

Queries Iceberg tables via Lakekeeper REST Catalog:

• Catalog: iceberg
• Storage: MinIO S3-compatible object storage
• REST Catalog: Lakekeeper (Apache Iceberg REST Catalog implementation)
• Authentication: OAuth2 client credentials flow with Keycloak

How It Works:

1. Trino authenticates to Lakekeeper using OAuth2 (client credentials flow)
2. Lakekeeper provides Iceberg table metadata from its catalog
3. Trino reads actual data files directly from MinIO using static S3 credentials
4. Vended credentials are disabled; Trino uses pre-configured MinIO access keys

Configuration:

The following settings are automatically configured during installation when MinIO storage is enabled:

• Service account enabled on Trino Keycloak client
• lakekeeper client scope added to Trino client
• Audience mapper configured to include aud: lakekeeper in JWT tokens
• S3 file system factory enabled (fs.native-s3.enabled=true)
• Static MinIO credentials provided via Kubernetes secrets

Example Usage:

-- List all namespaces (schemas)
SHOW SCHEMAS FROM iceberg;

-- Create a namespace
CREATE SCHEMA iceberg.analytics;

-- List tables in a namespace
SHOW TABLES FROM iceberg.ecommerce;

-- Query table
SELECT * FROM iceberg.ecommerce.products LIMIT 10;

-- Create table
CREATE TABLE iceberg.analytics.sales (
    date DATE,
    product VARCHAR,
    amount DECIMAL(10,2)
);

Management

Upgrade Trino

just trino::upgrade

Updates the Helm deployment with current configuration.

Uninstall

# Keep PostgreSQL database
just trino::uninstall false

# Delete PostgreSQL database too
just trino::uninstall true

Cleanup All Resources

just trino::cleanup

Removes:

• PostgreSQL database
• Vault secrets
• Keycloak OAuth client

Authentication

Web UI (OAuth2)

• Uses Keycloak for authentication
• Requires valid user in the configured realm
• Automatic redirect to Keycloak login

JDBC/Metabase (Password)

• Username: admin
• Password: Retrieved via just trino::admin-password
• Stored in Vault at trino/password

Architecture

External Users
      ↓
Cloudflare Tunnel (HTTPS)
      ↓
Traefik Ingress
      ↓
Trino Coordinator (HTTP:8080)
      ├─ OAuth2 → Keycloak (Web UI auth)
      └─ Password file (JDBC auth)
      ↓
Trino Workers (HTTP:8080)
      ↓
Data Sources:
  - PostgreSQL (CloudNativePG)
    └─ Direct SQL connection

  - Iceberg Tables
    ├─ Metadata: Lakekeeper (REST Catalog)
    │   └─ OAuth2 → Keycloak (client credentials)
    └─ Data: MinIO (S3)
        └─ Static credentials

Troubleshooting

Check Pod Status

kubectl get pods -n trino

View Coordinator Logs

kubectl logs -n trino -l app.kubernetes.io/component=coordinator --tail=100

View Worker Logs

kubectl logs -n trino -l app.kubernetes.io/component=worker --tail=100

Test Authentication

# From inside coordinator pod
kubectl exec -n trino deployment/trino-coordinator -- \
  curl -u admin:PASSWORD http://localhost:8080/v1/info

Common Issues

Metabase Sync Fails

• Ensure catalog is specified in connection settings (e.g., postgresql or iceberg)
• For Iceberg catalog, verify Lakekeeper is running: kubectl get pods -n lakekeeper
• Check Trino coordinator logs for errors
• Verify PostgreSQL/Iceberg connectivity
• For Iceberg issues, check OAuth2 token: Service account should be enabled on Trino client

OAuth2 Login Fails

• Verify Keycloak OAuth client exists: just keycloak::list-clients
• Check redirect URL matches Trino host
• Ensure Keycloak is accessible from Trino pods

Password Authentication Fails

• Retrieve current password: just trino::admin-password
• Ensure SSL/TLS is enabled in JDBC URL
• For internal testing, HTTP is supported via http-server.authentication.allow-insecure-over-http=true

References

• Trino Documentation
• Trino Helm Chart
• OAuth2 Authentication
• Password Authentication
• PostgreSQL Connector
• Iceberg Connector
• Lakekeeper (Iceberg REST Catalog)
• Apache Iceberg