Add SSH tunnel support to MSSQL driver

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/godror/godror v0.41.0
 	github.com/google/go-cmp v0.5.9
 	github.com/jackc/pgx/v4 v4.18.1
+	github.com/jfcote87/sshdb v0.5.3
 	github.com/k0kubun/colorstring v0.0.0-20150214042306-9440f1994b88 // indirect
 	github.com/sourcegraph/jsonrpc2 v0.2.0
 	github.com/urfave/cli/v2 v2.27.0

go.sum

@@ -136,6 +136,8 @@ github.com/jackc/puddle v0.0.0-20190608224051-11cab39313c9/go.mod h1:m4B5Dj62Y0f
 github.com/jackc/puddle v1.1.3/go.mod h1:m4B5Dj62Y0fbyuIc15OsIqK0+JU8nkqQjsgx7dvjSWk=
 github.com/jackc/puddle v1.3.0/go.mod h1:m4B5Dj62Y0fbyuIc15OsIqK0+JU8nkqQjsgx7dvjSWk=
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
+github.com/jfcote87/sshdb v0.5.3 h1:c0I3+ScEbT0mjvpoY8qbVNfR4Y9Q5JWh52WnmjfsuV0=
+github.com/jfcote87/sshdb v0.5.3/go.mod h1:YIGPRF3vtRG1Cvpwa1LaQvmrsIEPKC9WqF+ZU5rInUw=
 github.com/joeshaw/multierror v0.0.0-20140124173710-69b34d4ec901 h1:rp+c0RAYOWj8l6qbCUTSiRLG/iKnW3K3/QfPPuSsBt4=
 github.com/joeshaw/multierror v0.0.0-20140124173710-69b34d4ec901/go.mod h1:Z86h9688Y0wesXCyonoVr47MasHilkuLMqGhRZ4Hpak=
 github.com/k0kubun/colorstring v0.0.0-20150214042306-9440f1994b88 h1:uC1QfSlInpQF+M0ao65imhwqKnz3Q2z/d8PWZRMQvDM=

internal/database/mssql.go

@@ -1,6 +1,7 @@
 package database
 
 import (
+	"os"
 	"context"
 	"database/sql"
 	"fmt"
@@ -10,6 +11,8 @@ import (
 
 	_ "github.com/denisenkom/go-mssqldb"
 	"github.com/sqls-server/sqls/dialect"
+	"github.com/jfcote87/sshdb"
+	"github.com/jfcote87/sshdb/mssql"
 	"golang.org/x/crypto/ssh"
 )
 
@@ -21,21 +24,51 @@ func init() {
 func mssqlOpen(dbConnCfg *DBConfig) (*DBConnection, error) {
 	var (
 		conn    *sql.DB
-		sshConn *ssh.Client
 	)
 	dsn, err := genMssqlConfig(dbConnCfg)
 	if err != nil {
 		return nil, err
 	}
 
 	if dbConnCfg.SSHCfg != nil {
-		return nil, fmt.Errorf("connect via SSH is not supported")
-	}
-	dbConn, err := sql.Open("sqlserver", dsn)
-	if err != nil {
-		return nil, err
+		key, err := os.ReadFile(dbConnCfg.SSHCfg.PrivateKey)
+		if err != nil {
+			return nil, fmt.Errorf("unable to open private key")
+		}
+
+		signer, err := ssh.ParsePrivateKeyWithPassphrase(key, []byte(dbConnCfg.SSHCfg.PassPhrase))
+		if err != nil {
+			return nil, fmt.Errorf("unable to decrypt private key")
+		}
+
+		cfg := &ssh.ClientConfig {
+			User: dbConnCfg.SSHCfg.User,
+			Auth: []ssh.AuthMethod {
+				ssh.PublicKeys(signer),
+			},
+			HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+		}
+
+		remoteAddr := fmt.Sprintf("%s:%d", dbConnCfg.SSHCfg.Host, dbConnCfg.SSHCfg.Port)
+
+		tunnel, err := sshdb.New(cfg, remoteAddr)
+		if err != nil {
+			return nil, fmt.Errorf("%v", err)
+		}
+
+		connector, err := tunnel.OpenConnector(mssql.TunnelDriver, dsn)
+		if err != nil {
+			return nil, err
+		}
+
+		conn = sql.OpenDB(connector)
+	} else {
+		conn, err = sql.Open("mssql", dsn)
+		if err != nil {
+			return nil, err
+		}
 	}
-	conn = dbConn
+
 	if err = conn.Ping(); err != nil {
 		return nil, err
 	}
@@ -45,7 +78,6 @@ func mssqlOpen(dbConnCfg *DBConfig) (*DBConnection, error) {
 
 	return &DBConnection{
 		Conn:    conn,
-		SSHConn: sshConn,
 	}, nil
 }