Add passwdCmd config option

It iso now possible to define a command that is executed in order to
optain the password. This is useful in situations, where your database
is manged by a cloud provider and you are using the cloud providers IAM
solution to gain the password.

Fixes sqls-server#154

README.md

@@ -111,6 +111,14 @@ connections:
     params:
       autocommit: "true"
       tls: skip-verify
+  - alias: managed_mysql
+    driver: mysql
+    proto: tcp
+    user: root
+    passwdCmd: ["echo", "-n", "super_secure"]
+    host: 127.0.0.1
+    port: 13306
+    dbName: world
   - alias: mysql_via_ssh
     driver: mysql
     proto: tcp
@@ -232,7 +240,9 @@ The first setting in `connections` is the default connection.
 
 ### connections
 
-`dataSourceName` takes precedence over the value set in `proto`, `user`, `passwd`, `host`, `port`, `dbName`, `params`.
+`dataSourceName` takes precedence over the value set in `proto`, `user`, `passwd`, `passwdCmd`, `host`, `port`, `dbName`, `params`.
+
+`passwdCmd` takes precedence over the value set in `passwd`.
 
 | Key            | Description                                 |
 | -------------- | ------------------------------------------- |
@@ -242,6 +252,7 @@ The first setting in `connections` is the default connection.
 | proto          | `tcp`, `udp`, `unix`.                       |
 | user           | User name                                   |
 | passwd         | Password                                    |
+| passwdCmd      | Command to be executed to get password (Array)   |
 | host           | Host                                        |
 | port           | Port                                        |
 | path           | unix socket path                            |

internal/config/config_test.go

@@ -39,6 +39,16 @@ func TestGetConfig(t *testing.T) {
 						DBName: "world",
 						Params: map[string]string{"autocommit": "true", "tls": "skip-verify"},
 					},
+					{
+						Alias:     "sqls_managed",
+						Driver:    "mysql",
+						Proto:     "tcp",
+						User:      "root",
+						PasswdCmd: []string{"echo", "topsecret"},
+						Host:      "127.0.0.1",
+						Port:      13306,
+						DBName:    "world",
+					},
 					{
 						Alias:          "sqls_sqlite3",
 						Driver:         "sqlite3",

internal/config/testdata/basic.yml

@@ -13,6 +13,16 @@ connections:
     params:
       autocommit: "true"
       tls: skip-verify
+  - alias: sqls_managed
+    driver: mysql
+    dataSourceName: ""
+    proto: tcp
+    user: root
+    passwdCmd: ["echo", "topsecret"]
+    host: 127.0.0.1
+    port: 13306
+    path: ""
+    dbName: world
   - alias: sqls_sqlite3
     driver: sqlite3
     dataSourceName: "file:/home/sqls-server/chinook.db"

internal/database/clickhouse.go

@@ -101,10 +101,15 @@ func genClickhouseDsn(dbConfig *DBConfig) (string, error) {
 		return "", fmt.Errorf("unsupported protocol %s", dbConfig.Proto)
 	}
 
-	if dbConfig.Passwd == "" {
+	passwd, err := dbConfig.ResolvePassword()
+	if err != nil {
+		return "", err
+	}
+
+	if passwd == "" {
 		u.User = url.User(dbConfig.User)
 	} else {
-		u.User = url.UserPassword(dbConfig.User, dbConfig.Passwd)
+		u.User = url.UserPassword(dbConfig.User, passwd)
 	}
 
 	u.Host = fmt.Sprintf("%s:%d", dbConfig.Host, dbConfig.Port)
@@ -131,8 +136,13 @@ func genClickhouseConfig(dbConfig *DBConfig) (*clickhouse.Options, error) {
 
 	cfg := &clickhouse.Options{}
 
+	passwd, err := dbConfig.ResolvePassword()
+	if err != nil {
+		return nil, err
+	}
+
 	cfg.Auth.Username = dbConfig.User
-	cfg.Auth.Password = dbConfig.Passwd
+	cfg.Auth.Password = passwd
 	cfg.Auth.Database = dbConfig.DBName
 
 	switch dbConfig.Proto {

internal/database/config.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"os/exec"
 
 	"github.com/sqls-server/sqls/dialect"
 	"golang.org/x/crypto/ssh"
@@ -25,6 +26,7 @@ type DBConfig struct {
 	Proto          Proto                  `json:"proto" yaml:"proto"`
 	User           string                 `json:"user" yaml:"user"`
 	Passwd         string                 `json:"passwd" yaml:"passwd"`
+	PasswdCmd      []string               `json:"passwdCmd" yaml:"passwdCmd"`
 	Host           string                 `json:"host" yaml:"host"`
 	Port           int                    `json:"port" yaml:"port"`
 	Path           string                 `json:"path" yaml:"path"`
@@ -33,6 +35,20 @@ type DBConfig struct {
 	SSHCfg         *SSHConfig             `json:"sshConfig" yaml:"sshConfig"`
 }
 
+func (c *DBConfig) ResolvePassword() (string, error) {
+	if len(c.PasswdCmd) == 0 {
+		return c.Passwd, nil
+	}
+
+	cmd := exec.Command(c.PasswdCmd[0], c.PasswdCmd[1:]...) // nolint:gosec // The whole feature is allowing the user to run a provided command.
+	data, err := cmd.Output()
+	if err != nil {
+		return "", err
+	}
+
+	return string(data), nil
+}
+
 func (c *DBConfig) Validate() error {
 	if c.Driver == "" {
 		return errors.New("required: connections[].driver")
@@ -101,8 +117,8 @@ func (c *DBConfig) Validate() error {
 			if c.User == "" {
 				return errors.New("required: connections[].user")
 			}
-			if c.Passwd == "" {
-				return errors.New("required: connections[].Passwd")
+			if len(c.PasswdCmd) == 0 && c.Passwd == "" {
+				return errors.New("required: connections[].PasswdCmd or connections[].Passwd")
 			}
 			if c.Host == "" {
 				return errors.New("required: connections[].Host")
@@ -129,7 +145,7 @@ func (c *DBConfig) Validate() error {
 					return errors.New("required: connections[].host")
 				}
 			case ProtoUDP, ProtoUnix:
-      default:
+			default:
 				return errors.New("invalid: connections[].proto")
 			}
 			if c.SSHCfg != nil {

internal/database/config_test.go

@@ -0,0 +1,64 @@
+package database
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestResolvePassword(t *testing.T) {
+	type testCase struct {
+		title    string
+		dbConfig DBConfig
+		want     string
+		wantErr  bool
+	}
+
+	testCases := []testCase{
+		{
+			title: "only password",
+			dbConfig: DBConfig{
+				Passwd: "test",
+			},
+			want: "test",
+		},
+		{
+			title: "only command",
+			dbConfig: DBConfig{
+				PasswdCmd: []string{"echo", "-n", "secure"},
+			},
+			want: "secure",
+		},
+		{
+			title: "password and command",
+			dbConfig: DBConfig{
+				Passwd:    "test",
+				PasswdCmd: []string{"echo", "-n", "secure"},
+			},
+			want: "secure",
+		},
+		{
+			title: "failing command",
+			dbConfig: DBConfig{
+				Passwd:    "test",
+				PasswdCmd: []string{"false"},
+			},
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range testCases {
+		t.Run(tt.title, func(t *testing.T) {
+			got, err := tt.dbConfig.ResolvePassword()
+			if err != nil {
+				if !tt.wantErr {
+					t.Errorf("ResolvePassword() error = %v, wantErr %v", err, tt.wantErr)
+					return
+				}
+			}
+			if diff := cmp.Diff(tt.want, got); diff != "" {
+				t.Errorf("unmatch (- want, + got):\n%s", diff)
+			}
+		})
+	}
+}

internal/database/mssql.go

@@ -1,18 +1,18 @@
 package database
 
 import (
-	"os"
 	"context"
 	"database/sql"
 	"fmt"
 	"log"
 	"net/url"
+	"os"
 	"strconv"
 
 	_ "github.com/denisenkom/go-mssqldb"
-	"github.com/sqls-server/sqls/dialect"
 	"github.com/jfcote87/sshdb"
 	"github.com/jfcote87/sshdb/mssql"
+	"github.com/sqls-server/sqls/dialect"
 	"golang.org/x/crypto/ssh"
 )
 
@@ -23,7 +23,7 @@ func init() {
 
 func mssqlOpen(dbConnCfg *DBConfig) (*DBConnection, error) {
 	var (
-		conn    *sql.DB
+		conn *sql.DB
 	)
 	dsn, err := genMssqlConfig(dbConnCfg)
 	if err != nil {
@@ -41,9 +41,9 @@ func mssqlOpen(dbConnCfg *DBConfig) (*DBConnection, error) {
 			return nil, fmt.Errorf("unable to decrypt private key")
 		}
 
-		cfg := &ssh.ClientConfig {
+		cfg := &ssh.ClientConfig{
 			User: dbConnCfg.SSHCfg.User,
-			Auth: []ssh.AuthMethod {
+			Auth: []ssh.AuthMethod{
 				ssh.PublicKeys(signer),
 			},
 			HostKeyCallback: ssh.InsecureIgnoreHostKey(),
@@ -77,7 +77,7 @@ func mssqlOpen(dbConnCfg *DBConfig) (*DBConnection, error) {
 	conn.SetMaxOpenConns(DefaultMaxOpenConns)
 
 	return &DBConnection{
-		Conn:    conn,
+		Conn: conn,
 	}, nil
 }
 
@@ -376,9 +376,14 @@ func genMssqlConfig(connCfg *DBConfig) (string, error) {
 		return connCfg.DataSourceName, nil
 	}
 
+	passwd, err := connCfg.ResolvePassword()
+	if err != nil {
+		return "", err
+	}
+
 	q := url.Values{}
 	q.Set("user", connCfg.User)
-	q.Set("password", connCfg.Passwd)
+	q.Set("password", passwd)
 	q.Set("database", connCfg.DBName)
 
 	switch connCfg.Proto {

internal/database/mysql.go

@@ -94,8 +94,13 @@ func genMysqlConfig(connCfg *DBConfig) (*mysql.Config, error) {
 		return mysql.ParseDSN(connCfg.DataSourceName)
 	}
 
+	passwd, err := connCfg.ResolvePassword()
+	if err != nil {
+		return nil, err
+	}
+
 	cfg.User = connCfg.User
-	cfg.Passwd = connCfg.Passwd
+	cfg.Passwd = passwd
 	cfg.DBName = connCfg.DBName
 
 	switch connCfg.Proto {
@@ -116,7 +121,7 @@ func genMysqlConfig(connCfg *DBConfig) (*mysql.Config, error) {
 		}
 		cfg.Addr = connCfg.Path
 		cfg.Net = string(connCfg.Proto)
-  case ProtoHTTP:
+	case ProtoHTTP:
 	default:
 		return nil, fmt.Errorf("default addr for network %s unknown", connCfg.Proto)
 	}

internal/database/oracle.go

@@ -50,7 +50,12 @@ func genOracleConfig(connCfg *DBConfig) (string, error) {
 	if port == 0 {
 		port = 1521
 	}
-	DSName := connCfg.User + "/" + connCfg.Passwd + "@" + host + ":" + strconv.Itoa(port) + "/" + connCfg.DBName
+  passwd, err := connCfg.ResolvePassword()
+  if err != nil {
+    return "", err
+  }
+
+	DSName := connCfg.User + "/" + passwd + "@" + host + ":" + strconv.Itoa(port) + "/" + connCfg.DBName
 	return DSName, nil
 }
 
@@ -106,7 +111,7 @@ func (db *OracleDBRepository) SchemaTables(ctx context.Context) (map[string][]st
 		ctx,
 		`
 	SELECT OWNER, TABLE_NAME
-      FROM SYS.ALL_TABLES 
+      FROM SYS.ALL_TABLES
   ORDER BY OWNER, TABLE_NAME
 		`)
 	if err != nil {

internal/database/postgresql.go

@@ -396,9 +396,14 @@ func genPostgresConfig(connCfg *DBConfig) (string, error) {
 		return connCfg.DataSourceName, nil
 	}
 
+	passwd, err := connCfg.ResolvePassword()
+	if err != nil {
+		return "", err
+	}
+
 	q := url.Values{}
 	q.Set("user", connCfg.User)
-	q.Set("password", connCfg.Passwd)
+	q.Set("password", passwd)
 	q.Set("dbname", connCfg.DBName)
 
 	switch connCfg.Proto {

internal/database/vertica.go

@@ -51,7 +51,12 @@ func genVerticaConfig(connCfg *DBConfig) (string, error) {
 		port = 5433
 	}
 
-	DSName := connCfg.User + "/" + connCfg.Passwd + "@" + host + ":" + strconv.Itoa(port) + "/" + connCfg.DBName
+	passwd, err := connCfg.ResolvePassword()
+	if err != nil {
+		return "", err
+	}
+
+	DSName := connCfg.User + "/" + passwd + "@" + host + ":" + strconv.Itoa(port) + "/" + connCfg.DBName
 	return DSName, nil
 }