Files
minstrel/internal/db/db.go
T

91 lines
2.6 KiB
Go

package db
import (
"context"
"embed"
"errors"
"fmt"
"io/fs"
"log/slog"
"github.com/golang-migrate/migrate/v4"
_ "github.com/golang-migrate/migrate/v4/database/pgx/v5"
"github.com/golang-migrate/migrate/v4/source/iofs"
"github.com/jackc/pgx/v5/pgxpool"
)
//go:embed migrations/*.sql
var migrationsFS embed.FS
// MigrationsFS exposes the embedded migration set for callers that need
// raw access (e.g. tests that construct their own migration runner).
func MigrationsFS() fs.FS {
sub, err := fs.Sub(migrationsFS, "migrations")
if err != nil {
panic(fmt.Sprintf("db: sub fs: %v", err))
}
return sub
}
// Open establishes a pgx connection pool. The caller owns the returned pool
// and must Close() it on shutdown.
func Open(ctx context.Context, dsn string) (*pgxpool.Pool, error) {
if dsn == "" {
return nil, errors.New("db: database URL is empty")
}
pool, err := pgxpool.New(ctx, dsn)
if err != nil {
return nil, fmt.Errorf("db: create pool: %w", err)
}
if err := pool.Ping(ctx); err != nil {
pool.Close()
return nil, fmt.Errorf("db: ping: %w", err)
}
return pool, nil
}
// Migrate applies any pending migrations embedded in this package. It is safe
// to call concurrently with application traffic only if the database is idle;
// in practice this runs once at startup before the HTTP server binds.
func Migrate(dsn string, logger *slog.Logger) error {
if dsn == "" {
return errors.New("db: database URL is empty")
}
src, err := iofs.New(migrationsFS, "migrations")
if err != nil {
return fmt.Errorf("db: iofs source: %w", err)
}
m, err := migrate.NewWithSourceInstance("iofs", src, "pgx5://"+trimScheme(dsn))
if err != nil {
return fmt.Errorf("db: migrate init: %w", err)
}
defer func() {
if srcErr, dbErr := m.Close(); srcErr != nil || dbErr != nil {
logger.Warn("migrate close", "src_err", srcErr, "db_err", dbErr)
}
}()
if err := m.Up(); err != nil && !errors.Is(err, migrate.ErrNoChange) {
return fmt.Errorf("db: migrate up: %w", err)
}
version, dirty, verr := m.Version()
if verr != nil && !errors.Is(verr, migrate.ErrNilVersion) {
return fmt.Errorf("db: migrate version: %w", verr)
}
logger.Info("migrations applied", "version", version, "dirty", dirty)
return nil
}
// trimScheme rewrites a postgres://... or postgresql://... DSN to the bare
// form expected by the migrate pgx driver (it registers its own scheme).
func trimScheme(dsn string) string {
for _, prefix := range []string{"postgres://", "postgresql://"} {
if len(dsn) > len(prefix) && dsn[:len(prefix)] == prefix {
return dsn[len(prefix):]
}
}
return dsn
}