postgres

go wrappers, migrations, and testcontainers for postgres

🏗️ testcontainers

Testcontainers provides a container setup process from within the go application.

Because Linux requires root (or special permissions) for the Docker socket, it may be necessary to run sudo to run tests. Because sudo may not have go install added to PATH, use $(which go) to pass the full path of the go command. This is not necessary for CI tests, which have preconfigured permissions to the Docker socket.

sudo $(which go) test -v

⚙️ migrations

Files for initailizing (and tearing down) a database are included in the Migrations() function. See example-migrations for examples.

Tip

Migrations files should be numbered in the order they are to be run, first down, then up. As such, all down migrations should be odd; all up migrations should be even. Migrations will return a list of Migration objects, containing Direction, Filename, and Content.

usage

Use either local or embed filesystems to produce a slice of Migrations

// Migrations represents a single SQL migration file,
// including the direction, file name, and content
type Migration struct {
    Direction string
    Filename  string
    Content   string
}

local

For a local filesystem, just provide the path.

migrations, err := Migrations(os.DirFS("."), "migrations-dir-name", "up")
if err := nil {
    return fmt.Errorf("migration failed: %w", err)
}

embed

For an embed filesystem, provide the embed.FS and a filename.

//go:embed migrations
var migrationsDirEmbed embed.FS

migrations, err := Migrations(migrationsDirEmbed, "migrations-dir-name", "up")
if err := nil {
    return fmt.Errorf("migration failed: %w", err)
}

applying migrations

Loop over the migrations to apply them to your database.

for _, m := range migrations {
    log.Info("running migration",
        "file", m.Filename,
        "direction", m.Direction,
    )
    err := sql.Execute(m.Content)
    if err != nil {
        return fmt.Errorf("sql error on migration: %w", err)
    }
}