Databases

Ppacer uses a database to persist metadata of processes, their schedules, runs and so on. Default configuration uses SQLite as the database, but in fact any database which provides a driver for standard Go database/sql package can be supported.

All interactions with the database are made through ppacer/core/db.Client (API reference here).

// DB defines a set of operations required from a database. Most of methods are
// identical with standard `*sql.DB` type.
type DB interface {
  Begin() (*sql.Tx, error)
  Exec(query string, args ...any) (sql.Result, error)
  ExecContext(ctx context.Context, query string, args ...any) (sql.Result, error)
  Close() error
  DataSource() string
  Query(query string, args ...any) (*sql.Rows, error)
  QueryContext(ctx context.Context, query string, args ...any) (*sql.Rows, error)
  QueryRow(query string, args ...any) *sql.Row
  QueryRowContext(ctx context.Context, query string, args ...any) *sql.Row
}

// Client represents the main database client.
type Client struct {
  dbConn DB
  logger *slog.Logger
}

As mentioned default configuration uses SQLite. It’s materialized via db.NewSqliteClient. For unit tests and integration tests ppacer uses db.NewInMemoryClient or db.NewSqliteTmpClient.

Database schema

Database schemas are developed and maintained directly from ppacer ppacer/core/db package source code. Function db.SchemaStatements for a given SQL driver name returns a list of SQL statements that sets up ppacer database schema.

Support for other databases

Supporting other databases are planned after the MVP phase, so when we’ll have UI implemented. The first in line is PostgreSQL.