Database System

Wippy provides pooled SQL database entries for PostgreSQL and MySQL, plus a single-connection SQLite entry.

This page is a configuration reference. Unless a fence includes version, namespace, and entries, treat it as a fragment to place inside an existing entry list.

Entry Kinds

Configuration

Standard Databases (PostgreSQL, MySQL)

# src/data/_index.yaml
version: "1.0"
namespace: app.data

entries:
  - name: main_db
    kind: db.sql.postgres
    host: "localhost"
    port: 5432
    database: "myapp"
    username: "dbuser"
    password: ${env:app.secrets:db_password}
    pool:
      max_open: 25
      max_idle: 5
      max_lifetime: "1h"
    options:
      sslmode: "disable"
    lifecycle:
      auto_start: true

SQLite

  - name: cache_db
    kind: db.sql.sqlite
    file: "/var/data/cache.db"  # Use :memory: for in-memory
    pool:
      max_open: 4
      max_idle: 2
      max_lifetime: "1h"
    lifecycle:
      auto_start: true

Connection Fields

Standard Database Fields

SQLite Fields

max_mutation_changes and max_mutation_bytes bound the in-memory committed-mutation observer that feeds a db.cdc.sqlite source. Zero on either field selects the default; negative values are rejected. The bounds are conservative rather than exact: SQLite delivers a complete row to the pre-update hook, so one row can materialize before the bound rejects the candidate.

Secret and Environment Values

Pull connection values from the environment registry with ${env:NAME} placeholders, resolved at decode time. NAME is a registered variable's public name or its entry ID (e.g. app.secrets:db_password); it is not a raw OS env var.

- name: prod_db
  kind: db.sql.postgres
  host: ${env:DB_HOST}
  port: ${env:DB_PORT|5432}
  database: ${env:DB_NAME}
  username: ${env:DB_USER}
  password: ${env:app.secrets:db_password}

Connection Pool

Configure connection pooling behavior. Pool settings map to Go's database/sql connection pool.

pool:
  max_open: 25      # Limit concurrent connections
  max_idle: 5       # Keep 5 connections ready
  max_lifetime: "30m"  # Recycle connections every 30 minutes

DSN Formats

Each database type constructs a DSN from configuration. Any options are appended (sorted by key); none are included by default.

PostgreSQL {id="dsn-postgresql"}

host='host' port=port user='username' password='password' dbname='database' [option='value' ...]

Every value except the port is single-quoted, and embedded ' and \ are backslash-escaped, so hosts, passwords and option values containing spaces or quotes are passed through intact.

MySQL {id="dsn-mysql"}

username:password@tcp(host:port)/database[?option=value&...]

SQLite {id="dsn-sqlite"}

file:/path/to/database.db?mode=rwc
:memory:

Database Options

Common database-specific options:

PostgreSQL {id="options-postgresql"}

options:
  sslmode: "require"      # disable, require, verify-ca, verify-full
  connect_timeout: "10"   # Connection timeout in seconds
  application_name: "myapp"

MySQL {id="options-mysql"}

options:
  charset: "utf8mb4"
  parseTime: "true"       # Parse time values to time.Time
  loc: "Local"            # Timezone

SQLite {id="options-sqlite"}

SQLite does not apply the options map to its DSN. File databases always open with mode=rwc, and journal mode is always set to WAL. The options field is accepted but ignored.

Examples

PostgreSQL with SSL

- name: secure_postgres
  kind: db.sql.postgres
  host: "db.example.com"
  port: 5432
  database: "production"
  username: "app_user"
  password: ${env:app.secrets:db_password}
  pool:
    max_open: 50
    max_idle: 10
    max_lifetime: "1h"
  options:
    sslmode: "verify-full"
    sslcert: "/certs/client.crt"
    sslkey: "/certs/client.key"
    sslrootcert: "/certs/ca.crt"
  lifecycle:
    auto_start: true

MySQL Read Replica

- name: mysql_replica
  kind: db.sql.mysql
  host: "replica.db.example.com"
  port: 3306
  database: "app"
  username: "readonly"
  password: ${env:app.secrets:replica_password}
  pool:
    max_open: 20
    max_idle: 5
    max_lifetime: "30m"
  options:
    charset: "utf8mb4"
    parseTime: "true"
    readTimeout: "30s"

SQLite In-Memory

- name: test_db
  kind: db.sql.sqlite
  file: ":memory:"

Multiple Database Setup

entries:
  # Primary database
  - name: users_db
    kind: db.sql.postgres
    host: ${env:USERS_DB_HOST}
    port: 5432
    database: "users"
    username: ${env:USERS_DB_USER}
    password: ${env:app.secrets:users_db_password}
    lifecycle:
      auto_start: true

  # Analytics database
  - name: analytics_db
    kind: db.sql.mysql
    host: ${env:ANALYTICS_DB_HOST}
    port: 3306
    database: "analytics"
    username: ${env:ANALYTICS_DB_USER}
    password: ${env:app.secrets:analytics_db_password}
    lifecycle:
      auto_start: true

  # Local cache
  - name: cache
    kind: db.sql.sqlite
    file: "/var/cache/app.db"
    lifecycle:
      auto_start: true

Runtime Registration

Databases can be registered at runtime using the registry module.

Lua API

See SQL Module for query, transaction, and connection operations.

See Also

• SQL Module - Lua API reference
• Store - Key-value store backed by a db.sql.* database
• Queue - SQL-backed queue handler
• Change Data Capture - Streaming row-level changes from a db.sql.sqlite or Postgres database