feat: Add MySQL ent-based storage driver

Signed-off-by: m.nabokikh <maksim.nabokikh@flant.com>

storage/ent/mysql.go

@@ -0,0 +1,162 @@
+package ent
+
+import (
+	"context"
+	"crypto/sha256"
+	"crypto/tls"
+	"crypto/x509"
+	"database/sql"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"strconv"
+	"time"
+
+	entSQL "entgo.io/ent/dialect/sql"
+	"github.com/go-sql-driver/mysql"
+
+	// Register postgres driver.
+	_ "github.com/lib/pq"
+
+	"github.com/dexidp/dex/pkg/log"
+	"github.com/dexidp/dex/storage"
+	"github.com/dexidp/dex/storage/ent/client"
+	"github.com/dexidp/dex/storage/ent/db"
+)
+
+// nolint
+const (
+	// MySQL SSL modes
+	mysqlSSLTrue       = "true"
+	mysqlSSLFalse      = "false"
+	mysqlSSLSkipVerify = "skip-verify"
+	mysqlSSLCustom     = "custom"
+)
+
+// MySQL options for creating an SQL db.
+type MySQL struct {
+	NetworkDB
+
+	SSL SSL `json:"ssl"`
+
+	params map[string]string
+}
+
+// Open always returns a new in sqlite3 storage.
+func (m *MySQL) Open(logger log.Logger) (storage.Storage, error) {
+	logger.Debug("experimental ent-based storage driver is enabled")
+	drv, err := m.driver()
+	if err != nil {
+		return nil, err
+	}
+
+	databaseClient := client.NewDatabase(
+		client.WithClient(db.NewClient(db.Driver(drv))),
+		client.WithHasher(sha256.New),
+		// Set tx isolation leve for each transaction as dex does for postgres
+		client.WithTxIsolationLevel(sql.LevelSerializable),
+	)
+
+	if err := databaseClient.Schema().Create(context.TODO()); err != nil {
+		return nil, err
+	}
+
+	return databaseClient, nil
+}
+
+func (m *MySQL) driver() (*entSQL.Driver, error) {
+	var tlsConfig string
+
+	switch {
+	case m.SSL.CAFile != "" || m.SSL.CertFile != "" || m.SSL.KeyFile != "":
+		if err := m.makeTLSConfig(); err != nil {
+			return nil, fmt.Errorf("failed to make TLS config: %v", err)
+		}
+		tlsConfig = mysqlSSLCustom
+	case m.SSL.Mode == "":
+		tlsConfig = mysqlSSLTrue
+	default:
+		tlsConfig = m.SSL.Mode
+	}
+
+	drv, err := entSQL.Open("mysql", m.dsn(tlsConfig))
+	if err != nil {
+		return nil, err
+	}
+
+	if m.MaxIdleConns == 0 {
+		/* Override default behaviour to fix https://github.com/dexidp/dex/issues/1608 */
+		drv.DB().SetMaxIdleConns(0)
+	} else {
+		drv.DB().SetMaxIdleConns(m.MaxIdleConns)
+	}
+
+	return drv, nil
+}
+
+func (m *MySQL) dsn(tlsConfig string) string {
+	cfg := mysql.Config{
+		User:                 m.User,
+		Passwd:               m.Password,
+		DBName:               m.Database,
+		AllowNativePasswords: true,
+
+		Timeout: time.Second * time.Duration(m.ConnectionTimeout),
+
+		TLSConfig: tlsConfig,
+
+		ParseTime: true,
+		Params: make(map[string]string),
+	}
+
+	if m.Host != "" {
+		if m.Host[0] != '/' {
+			cfg.Net = "tcp"
+			cfg.Addr = m.Host
+
+			if m.Port != 0 {
+				cfg.Addr = net.JoinHostPort(m.Host, strconv.Itoa(int(m.Port)))
+			}
+		} else {
+			cfg.Net = "unix"
+			cfg.Addr = m.Host
+		}
+	}
+
+	for k, v := range m.params {
+		cfg.Params[k] = v
+	}
+
+	return cfg.FormatDSN()
+}
+
+func (m *MySQL) makeTLSConfig() error {
+	cfg := &tls.Config{}
+
+	if m.SSL.CAFile != "" {
+		rootCertPool := x509.NewCertPool()
+
+		pem, err := ioutil.ReadFile(m.SSL.CAFile)
+		if err != nil {
+			return err
+		}
+
+		if ok := rootCertPool.AppendCertsFromPEM(pem); !ok {
+			return fmt.Errorf("failed to append PEM")
+		}
+		cfg.RootCAs = rootCertPool
+	}
+
+	if m.SSL.CertFile != "" && m.SSL.KeyFile != "" {
+		clientCert := make([]tls.Certificate, 0, 1)
+		certs, err := tls.LoadX509KeyPair(m.SSL.CertFile, m.SSL.KeyFile)
+		if err != nil {
+			return err
+		}
+		clientCert = append(clientCert, certs)
+		cfg.Certificates = clientCert
+	}
+
+	mysql.RegisterTLSConfig(mysqlSSLCustom, cfg)
+	return nil
+}