Postgres - add x-migrations-table-quoted url query option (#95)

database/pgx/README.md

@@ -5,6 +5,7 @@
 | URL Query  | WithInstance Config | Description |
 |------------|---------------------|-------------|
 | `x-migrations-table` | `MigrationsTable` | Name of the migrations table |
+| `x-migrations-table-quoted` | `MigrationsTableQuoted` | By default, migrate quotes the migration table for SQL injection safety reasons. This option disable quoting and naively checks that you have quoted the migration table name. e.g. `"my_schema"."schema_migrations"` |
 | `x-statement-timeout` | `StatementTimeout` | Abort any statement that takes more than the specified number of milliseconds |
 | `x-multi-statement` | `MultiStatementEnabled` | Enable multi-statement execution (default: false) |
 | `x-multi-statement-max-size` | `MultiStatementMaxSize` | Maximum size of single statement in bytes (default: 10MB) |

database/pgx/pgx.go

@@ -9,6 +9,7 @@ import (
 	"io"
 	"io/ioutil"
 	nurl "net/url"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -46,6 +47,7 @@ type Config struct {
 	DatabaseName          string
 	SchemaName            string
 	StatementTimeout      time.Duration
+	MigrationsTableQuoted bool
 	MultiStatementEnabled bool
 	MultiStatementMaxSize int
 }
@@ -137,6 +139,17 @@ func (p *Postgres) Open(url string) (database.Driver, error) {
 	}
 
 	migrationsTable := purl.Query().Get("x-migrations-table")
+	migrationsTableQuoted := false
+	if s := purl.Query().Get("x-migrations-table-quoted"); len(s) > 0 {
+		migrationsTableQuoted, err = strconv.ParseBool(s)
+		if err != nil {
+			return nil, fmt.Errorf("Unable to parse option x-migrations-table-quoted: %w", err)
+		}
+	}
+	if (len(migrationsTable) > 0) && (migrationsTableQuoted) && ((migrationsTable[0] != '"') || (migrationsTable[len(migrationsTable)-1] != '"')) {
+		return nil, fmt.Errorf("x-migrations-table must be quoted (for instance '\"migrate\".\"schema_migrations\"') when x-migrations-table-quoted is enabled, current value is: %s", migrationsTable)
+	}
+
 	statementTimeoutString := purl.Query().Get("x-statement-timeout")
 	statementTimeout := 0
 	if statementTimeoutString != "" {
@@ -168,6 +181,7 @@ func (p *Postgres) Open(url string) (database.Driver, error) {
 	px, err := WithInstance(db, &Config{
 		DatabaseName:          purl.Path,
 		MigrationsTable:       migrationsTable,
+		MigrationsTableQuoted: migrationsTableQuoted,
 		StatementTimeout:      time.Duration(statementTimeout) * time.Millisecond,
 		MultiStatementEnabled: multiStatementEnabled,
 		MultiStatementMaxSize: multiStatementMaxSize,
@@ -321,7 +335,7 @@ func (p *Postgres) SetVersion(version int, dirty bool) error {
 		return &database.Error{OrigErr: err, Err: "transaction start failed"}
 	}
 
-	query := `TRUNCATE ` + quoteIdentifier(p.config.MigrationsTable)
+	query := `TRUNCATE ` + p.quoteIdentifier(p.config.MigrationsTable)
 	if _, err := tx.Exec(query); err != nil {
 		if errRollback := tx.Rollback(); errRollback != nil {
 			err = multierror.Append(err, errRollback)
@@ -333,7 +347,7 @@ func (p *Postgres) SetVersion(version int, dirty bool) error {
 	// empty schema version for failed down migration on the first migration
 	// See: https://github.com/golang-migrate/migrate/issues/330
 	if version >= 0 || (version == database.NilVersion && dirty) {
-		query = `INSERT INTO ` + quoteIdentifier(p.config.MigrationsTable) +
+		query = `INSERT INTO ` + p.quoteIdentifier(p.config.MigrationsTable) +
 			` (version, dirty) VALUES ($1, $2)`
 		if _, err := tx.Exec(query, version, dirty); err != nil {
 			if errRollback := tx.Rollback(); errRollback != nil {
@@ -351,7 +365,7 @@ func (p *Postgres) SetVersion(version int, dirty bool) error {
 }
 
 func (p *Postgres) Version() (version int, dirty bool, err error) {
-	query := `SELECT version, dirty FROM ` + quoteIdentifier(p.config.MigrationsTable) + ` LIMIT 1`
+	query := `SELECT version, dirty FROM ` + p.quoteIdentifier(p.config.MigrationsTable) + ` LIMIT 1`
 	err = p.conn.QueryRowContext(context.Background(), query).Scan(&version, &dirty)
 	switch {
 	case err == sql.ErrNoRows:
@@ -401,7 +415,7 @@ func (p *Postgres) Drop() (err error) {
 	if len(tableNames) > 0 {
 		// delete one by one ...
 		for _, t := range tableNames {
-			query = `DROP TABLE IF EXISTS ` + quoteIdentifier(t) + ` CASCADE`
+			query = `DROP TABLE IF EXISTS ` + p.quoteIdentifier(t) + ` CASCADE`
 			if _, err := p.conn.ExecContext(context.Background(), query); err != nil {
 				return &database.Error{OrigErr: err, Query: []byte(query)}
 			}
@@ -433,10 +447,29 @@ func (p *Postgres) ensureVersionTable() (err error) {
 	// users to also check the current version of the schema. Previously, even if `MigrationsTable` existed, the
 	// `CREATE TABLE IF NOT EXISTS...` query would fail because the user does not have the CREATE permission.
 	// Taken from https://github.com/mattes/migrate/blob/master/database/postgres/postgres.go#L258
-	var count int
-	query := `SELECT COUNT(1) FROM information_schema.tables WHERE table_name = $1 AND table_schema = (SELECT current_schema()) LIMIT 1`
-	row := p.conn.QueryRowContext(context.Background(), query, p.config.MigrationsTable)
+	var row *sql.Row
+	tableName := p.config.MigrationsTable
+	schemaName := ""
+	if p.config.MigrationsTableQuoted {
+		re := regexp.MustCompile(`"(.*?)"`)
+		result := re.FindAllStringSubmatch(p.config.MigrationsTable, -1)
+		tableName = result[len(result)-1][1]
+		if len(result) == 2 {
+			schemaName = result[0][1]
+		} else if len(result) > 2 {
+			return fmt.Errorf("\"%s\" MigrationsTable contains too many dot characters", p.config.MigrationsTable)
+		}
+	}
+	var query string
+	if len(schemaName) > 0 {
+		query = `SELECT COUNT(1) FROM information_schema.tables WHERE table_name = $1 AND table_schema = $2 LIMIT 1`
+		row = p.conn.QueryRowContext(context.Background(), query, tableName, schemaName)
+	} else {
+		query = `SELECT COUNT(1) FROM information_schema.tables WHERE table_name = $1 AND table_schema = (SELECT current_schema()) LIMIT 1`
+		row = p.conn.QueryRowContext(context.Background(), query, tableName)
+	}
 
+	var count int
 	err = row.Scan(&count)
 	if err != nil {
 		return &database.Error{OrigErr: err, Query: []byte(query)}
@@ -446,7 +479,7 @@ func (p *Postgres) ensureVersionTable() (err error) {
 		return nil
 	}
 
-	query = `CREATE TABLE IF NOT EXISTS ` + quoteIdentifier(p.config.MigrationsTable) + ` (version bigint not null primary key, dirty boolean not null)`
+	query = `CREATE TABLE IF NOT EXISTS ` + p.quoteIdentifier(p.config.MigrationsTable) + ` (version bigint not null primary key, dirty boolean not null)`
 	if _, err = p.conn.ExecContext(context.Background(), query); err != nil {
 		return &database.Error{OrigErr: err, Query: []byte(query)}
 	}
@@ -455,7 +488,10 @@ func (p *Postgres) ensureVersionTable() (err error) {
 }
 
 // Copied from lib/pq implementation: https://github.com/lib/pq/blob/v1.9.0/conn.go#L1611
-func quoteIdentifier(name string) string {
+func (p *Postgres) quoteIdentifier(name string) string {
+	if p.config.MigrationsTableQuoted {
+		return name
+	}
 	end := strings.IndexRune(name, 0)
 	if end > -1 {
 		name = name[:end]

database/pgx/pgx_test.go

@@ -318,6 +318,74 @@ func TestWithSchema(t *testing.T) {
 	})
 }
 
+func TestMigrationTableOption(t *testing.T) {
+	dktesting.ParallelTest(t, specs, func(t *testing.T, c dktest.ContainerInfo) {
+		ip, port, err := c.FirstPort()
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		addr := pgConnectionString(ip, port)
+		p := &Postgres{}
+		d, _ := p.Open(addr)
+		defer func() {
+			if err := d.Close(); err != nil {
+				t.Fatal(err)
+			}
+		}()
+
+		// create migrate schema
+		if err := d.Run(strings.NewReader("CREATE SCHEMA migrate AUTHORIZATION postgres")); err != nil {
+			t.Fatal(err)
+		}
+
+		// bad unquoted x-migrations-table parameter
+		wantErr := "x-migrations-table must be quoted (for instance '\"migrate\".\"schema_migrations\"') when x-migrations-table-quoted is enabled, current value is: migrate.schema_migrations"
+		d, err = p.Open(fmt.Sprintf("postgres://postgres:%s@%v:%v/postgres?sslmode=disable&x-migrations-table=migrate.schema_migrations&x-migrations-table-quoted=1",
+			pgPassword, ip, port))
+		if (err != nil) && (err.Error() != wantErr) {
+			t.Fatalf("expected '%s' but got '%s'", wantErr, err.Error())
+		}
+
+		// too many quoted x-migrations-table parameters
+		wantErr = "\"\"migrate\".\"schema_migrations\".\"toomany\"\" MigrationsTable contains too many dot characters"
+		d, err = p.Open(fmt.Sprintf("postgres://postgres:%s@%v:%v/postgres?sslmode=disable&x-migrations-table=\"migrate\".\"schema_migrations\".\"toomany\"&x-migrations-table-quoted=1",
+			pgPassword, ip, port))
+		if (err != nil) && (err.Error() != wantErr) {
+			t.Fatalf("expected '%s' but got '%s'", wantErr, err.Error())
+		}
+
+		// good quoted x-migrations-table parameter
+		d, err = p.Open(fmt.Sprintf("postgres://postgres:%s@%v:%v/postgres?sslmode=disable&x-migrations-table=\"migrate\".\"schema_migrations\"&x-migrations-table-quoted=1",
+			pgPassword, ip, port))
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		// make sure migrate.schema_migrations table exists
+		var exists bool
+		if err := d.(*Postgres).conn.QueryRowContext(context.Background(), "SELECT EXISTS (SELECT 1 FROM information_schema.tables WHERE table_name = 'schema_migrations' AND table_schema = 'migrate')").Scan(&exists); err != nil {
+			t.Fatal(err)
+		}
+		if !exists {
+			t.Fatalf("expected table migrate.schema_migrations to exist")
+		}
+
+		d, err = p.Open(fmt.Sprintf("postgres://postgres:%s@%v:%v/postgres?sslmode=disable&x-migrations-table=migrate.schema_migrations",
+			pgPassword, ip, port))
+		if err != nil {
+			t.Fatal(err)
+		}
+		if err := d.(*Postgres).conn.QueryRowContext(context.Background(), "SELECT EXISTS (SELECT 1 FROM information_schema.tables WHERE table_name = 'migrate.schema_migrations' AND table_schema = (SELECT current_schema()))").Scan(&exists); err != nil {
+			t.Fatal(err)
+		}
+		if !exists {
+			t.Fatalf("expected table 'migrate.schema_migrations' to exist")
+		}
+
+	})
+}
+
 func TestFailToCreateTableWithoutPermissions(t *testing.T) {
 	dktesting.ParallelTest(t, specs, func(t *testing.T, c dktest.ContainerInfo) {
 		ip, port, err := c.FirstPort()
@@ -373,6 +441,18 @@ func TestFailToCreateTableWithoutPermissions(t *testing.T) {
 		if !strings.Contains(e.OrigErr.Error(), "permission denied for schema barfoo") {
 			t.Fatal(e)
 		}
+
+		// re-connect using that x-migrations-table and x-migrations-table-quoted
+		d2, err = p.Open(fmt.Sprintf("postgres://not_owner:%s@%v:%v/postgres?sslmode=disable&x-migrations-table=\"barfoo\".\"schema_migrations\"&x-migrations-table-quoted=1",
+			pgPassword, ip, port))
+
+		if !errors.As(err, &e) || err == nil {
+			t.Fatal("Unexpected error, want permission denied error. Got: ", err)
+		}
+
+		if !strings.Contains(e.OrigErr.Error(), "permission denied for schema barfoo") {
+			t.Fatal(e)
+		}
 	})
 }
 
@@ -679,5 +759,44 @@ func Test_computeLineFromPos(t *testing.T) {
 			run(true, true)
 		})
 	}
+}
+
+func Test_quoteIdentifier(t *testing.T) {
+	testcases := []struct {
+		migrationsTableQuoted bool
+		migrationsTable       string
+		expected              string
+	}{
+		{
+			false,
+			"schema_name.table_name",
+			"\"schema_name.table_name\"",
+		},
+		{
+			false,
+			"table_name",
+			"\"table_name\"",
+		},
+		{
+			true,
+			"\"schema_name\".\"table_name\"",
+			"\"schema_name\".\"table_name\"",
+		},
+		{
+			true,
+			"\"table_name\"",
+			"\"table_name\"",
+		},
+	}
+	p := &Postgres{
+		config: &Config{},
+	}
 
+	for _, tc := range testcases {
+		p.config.MigrationsTableQuoted = tc.migrationsTableQuoted
+		got := p.quoteIdentifier(tc.migrationsTable)
+		if tc.expected != got {
+			t.Fatalf("expected %s but got %s", tc.expected, got)
+		}
+	}
 }

database/postgres/README.md

@@ -5,6 +5,7 @@
 | URL Query  | WithInstance Config | Description |
 |------------|---------------------|-------------|
 | `x-migrations-table` | `MigrationsTable` | Name of the migrations table |
+| `x-migrations-table-quoted` | `MigrationsTableQuoted` | By default, migrate quotes the migration table for SQL injection safety reasons. This option disable quoting and naively checks that you have quoted the migration table name. e.g. `"my_schema"."schema_migrations"` |
 | `x-statement-timeout` | `StatementTimeout` | Abort any statement that takes more than the specified number of milliseconds |
 | `x-multi-statement` | `MultiStatementEnabled` | Enable multi-statement execution (default: false) |
 | `x-multi-statement-max-size` | `MultiStatementMaxSize` | Maximum size of single statement in bytes (default: 10MB) |