go-db

A tiny module for lazy me, to connect database.

This module uses a predefined set of environment variables to connect databases using database/sql.

Usage

Just call Connect() or ConnectX() to establish database connections.

import (
    "database/sql"
    "os"
    "github.com/eidng8/go-db"

    "<your-package>/ent"
)

func getEntClient() *ent.Client {
    return ent.NewClient(ent.Driver(entsql.OpenDB(db.ConnectX())))
}

Environment Variables

DB_DRIVER

REQUIRED and cannot be empty. Determines what kind of database to connect. Can be any driver supported by database/sql, such as mysql, sqlite3, pgx, etc. Remember to import proper driver module to your package.

DB_DSN

REQUIRED for connections other than MySQL. A complete DSN string to be used to establish connection to database. When set, this variable is passed directly to sql.Open(). For MySQL, if this variable is not set, variables below will be used to configure the connection.

Variables specific to MySQL

These variables are used to configure the connection to MySQL, if DB_DSN is not set.

DB_USER

REQUIRED and cannot be empty. Determines the username to connect to database.

DB_PASSWORD

REQUIRED and cannot be empty. Determines the password to connect to database.

DB_HOST

REQUIRED and cannot be empty. Determines the host to connect to.

DB_NAME

REQUIRED and cannot be empty. Determines the database name to connect to.

DB_PROTOCOL

OPTIONAL and defaults to tcp.

DB_COLLATION

OPTIONAL and defaults to utf8mb4_unicode_ci.

DB_TIMEZONE

OPTIONAL and defaults to UTC.

more configurations

When using Connect() or ConnectX() with environment variables, some configurations are also set:

mysql.Config{
    // .....
    AllowCleartextPasswords:  false,
    AllowFallbackToPlaintext: false,
    AllowNativePasswords:     true,
    AllowOldPasswords:        false,
    MultiStatements:          true,
    ParseTime:                true,
    // .....
}

Besides using Connect() or ConnectX(), ConnectMysql() can also be called with mysql.Config pointer:

cfg := mysql.Config{
    // You detailed configuration .....
}
ConnectMysql(cfg)

No matter which function is used to establish the connection, the following 3 settings are also called:

db.SetMaxIdleConns(10)
db.SetMaxOpenConns(100)
db.SetConnMaxLifetime(time.Hour)