chore: Move httpapi, httpmw, & database into coderd (#568)

* chore: Move httpmw to /coderd directory
httpmw is specific to coderd and should be scoped under coderd

* chore: Move httpapi to /coderd directory
httpapi is specific to coderd and should be scoped under coderd

* chore: Move database  to /coderd directory
database is specific to coderd and should be scoped under coderd

* chore: Update codecov & gitattributes for generated files
* chore: Update Makefile

coderd/database/migrate.go

@@ -0,0 +1,74 @@
+package database
+
+import (
+	"database/sql"
+	"embed"
+	"errors"
+
+	"github.com/golang-migrate/migrate/v4"
+	"github.com/golang-migrate/migrate/v4/database/postgres"
+	"github.com/golang-migrate/migrate/v4/source/iofs"
+	"golang.org/x/xerrors"
+)
+
+//go:embed migrations/*.sql
+var migrations embed.FS
+
+func migrateSetup(db *sql.DB) (*migrate.Migrate, error) {
+	sourceDriver, err := iofs.New(migrations, "migrations")
+	if err != nil {
+		return nil, xerrors.Errorf("create iofs: %w", err)
+	}
+
+	dbDriver, err := postgres.WithInstance(db, &postgres.Config{})
+	if err != nil {
+		return nil, xerrors.Errorf("wrap postgres connection: %w", err)
+	}
+
+	m, err := migrate.NewWithInstance("", sourceDriver, "", dbDriver)
+	if err != nil {
+		return nil, xerrors.Errorf("new migrate instance: %w", err)
+	}
+
+	return m, nil
+}
+
+// MigrateUp runs SQL migrations to ensure the database schema is up-to-date.
+func MigrateUp(db *sql.DB) error {
+	m, err := migrateSetup(db)
+	if err != nil {
+		return xerrors.Errorf("migrate setup: %w", err)
+	}
+
+	err = m.Up()
+	if err != nil {
+		if errors.Is(err, migrate.ErrNoChange) {
+			// It's OK if no changes happened!
+			return nil
+		}
+
+		return xerrors.Errorf("up: %w", err)
+	}
+
+	return nil
+}
+
+// MigrateDown runs all down SQL migrations.
+func MigrateDown(db *sql.DB) error {
+	m, err := migrateSetup(db)
+	if err != nil {
+		return xerrors.Errorf("migrate setup: %w", err)
+	}
+
+	err = m.Down()
+	if err != nil {
+		if errors.Is(err, migrate.ErrNoChange) {
+			// It's OK if no changes happened!
+			return nil
+		}
+
+		return xerrors.Errorf("down: %w", err)
+	}
+
+	return nil
+}