Use sqlx for db connection

pkg/shared/database.go

@@ -0,0 +1,41 @@
+// VulcanizeDB
+// Copyright © 2019 Vulcanize
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package shared
+
+import (
+	"github.com/ethereum/go-ethereum/statediff/indexer/database/sql/postgres"
+	"github.com/jmoiron/sqlx"
+)
+
+// NewDB creates a new db connection and initializes the connection pool
+func NewDB(connectString string, config postgres.Config) (*sqlx.DB, error) {
+	db, connectErr := sqlx.Connect("postgres", connectString)
+	if connectErr != nil {
+		return nil, postgres.ErrDBConnectionFailed(connectErr)
+	}
+	if config.MaxConns > 0 {
+		db.SetMaxOpenConns(config.MaxConns)
+	}
+	if config.MaxIdle > 0 {
+		db.SetMaxIdleConns(config.MaxIdle)
+	}
+	if config.MaxConnLifetime > 0 {
+		db.SetConnMaxLifetime(config.MaxConnLifetime)
+	}
+
+	return db, nil
+}