Add postgres support for socket parameter (#136)

Simplifies connecting to postgres via sockets (https://github.com/amacneil/dbmate/issues/107), and standardize the `socket` parameter across both mysql and postgresql.

Closes #107

README.md

@@ -127,7 +127,7 @@ protocol://username:password@host:port/database_name?options
 DATABASE_URL="mysql://username:password@127.0.0.1:3306/database_name"
 ```
 
-A socket parameter can be specified to connect through a unix socket file:
+A `socket` parameter can be specified to connect through a unix socket:
 
 ```sh
 DATABASE_URL="mysql://username:password@/database_name?socket=/var/run/mysqld/mysqld.sock"
@@ -141,6 +141,12 @@ When connecting to Postgres, you may need to add the `sslmode=disable` option to
 DATABASE_URL="postgres://username:password@127.0.0.1:5432/database_name?sslmode=disable"
 ```
 
+A `socket` or `host` parameter can be specified to connect through a unix socket (note: specify the directory only):
+
+```sh
+DATABASE_URL="postgres://username:password@/database_name?socket=/var/run/postgresql"
+```
+
 **SQLite**
 
 SQLite databases are stored on the filesystem, so you do not need to specify a host. By default, files are relative to the current directory. For example, the following will create a database at `./db/database_name.sqlite3`:

pkg/dbmate/mysql_test.go

@@ -62,12 +62,20 @@ func TestNormalizeMySQLURLCustomSpecialChars(t *testing.T) {
 }
 
 func TestNormalizeMySQLURLSocket(t *testing.T) {
+	// test with no user/pass
 	u, err := url.Parse("mysql:///foo?socket=/var/run/mysqld/mysqld.sock&flag=on")
 	require.NoError(t, err)
 	require.Equal(t, "", u.Host)
 
 	s := normalizeMySQLURL(u)
 	require.Equal(t, "unix(/var/run/mysqld/mysqld.sock)/foo?flag=on&multiStatements=true", s)
+
+	// test with user/pass
+	u, err = url.Parse("mysql://bob:secret@fakehost/foo?socket=/var/run/mysqld/mysqld.sock&flag=on")
+	require.NoError(t, err)
+
+	s = normalizeMySQLURL(u)
+	require.Equal(t, "bob:secret@unix(/var/run/mysqld/mysqld.sock)/foo?flag=on&multiStatements=true", s)
 }
 
 func TestMySQLCreateDropDatabase(t *testing.T) {

pkg/dbmate/postgres.go

@@ -19,9 +19,47 @@ func init() {
 type PostgresDriver struct {
 }
 
+func normalizePostgresURL(u *url.URL) string {
+	hostname := u.Hostname()
+	port := u.Port()
+	query := u.Query()
+
+	// support socket parameter for consistency with mysql
+	if query.Get("socket") != "" {
+		query.Set("host", query.Get("socket"))
+		query.Del("socket")
+	}
+
+	// default hostname
+	if hostname == "" {
+		hostname = "localhost"
+	}
+
+	// host param overrides url hostname
+	if query.Get("host") != "" {
+		hostname = ""
+	}
+
+	// always specify a port
+	if query.Get("port") != "" {
+		port = query.Get("port")
+		query.Del("port")
+	}
+	if port == "" {
+		port = "5432"
+	}
+
+	// generate output URL
+	out, _ := url.Parse(u.String())
+	out.Host = fmt.Sprintf("%s:%s", hostname, port)
+	out.RawQuery = query.Encode()
+
+	return out.String()
+}
+
 // Open creates a new database connection
 func (drv PostgresDriver) Open(u *url.URL) (*sql.DB, error) {
-	return sql.Open("postgres", u.String())
+	return sql.Open("postgres", normalizePostgresURL(u))
 }
 
 func (drv PostgresDriver) openPostgresDB(u *url.URL) (*sql.DB, error) {
@@ -91,7 +129,7 @@ func postgresSchemaMigrationsDump(db *sql.DB) ([]byte, error) {
 func (drv PostgresDriver) DumpSchema(u *url.URL, db *sql.DB) ([]byte, error) {
 	// load schema
 	schema, err := runCommand("pg_dump", "--format=plain", "--encoding=UTF8",
-		"--schema-only", "--no-privileges", "--no-owner", u.String())
+		"--schema-only", "--no-privileges", "--no-owner", normalizePostgresURL(u))
 	if err != nil {
 		return nil, err
 	}

pkg/dbmate/postgres_test.go

@@ -34,6 +34,49 @@ func prepTestPostgresDB(t *testing.T) *sql.DB {
 	return db
 }
 
+func TestNormalizePostgresURLDefaults(t *testing.T) {
+	u, err := url.Parse("postgres:///foo")
+	require.NoError(t, err)
+	s := normalizePostgresURL(u)
+	require.Equal(t, "postgres://localhost:5432/foo", s)
+}
+
+func TestNormalizePostgresURLCustom(t *testing.T) {
+	u, err := url.Parse("postgres://bob:secret@myhost:1234/foo?bar=baz")
+	require.NoError(t, err)
+	s := normalizePostgresURL(u)
+	require.Equal(t, "postgres://bob:secret@myhost:1234/foo?bar=baz", s)
+}
+
+func TestNormalizePostgresURLHostPortParams(t *testing.T) {
+	u, err := url.Parse("postgres://bob:secret@myhost:1234/foo?port=9999&bar=baz")
+	require.NoError(t, err)
+	s := normalizePostgresURL(u)
+	require.Equal(t, "postgres://bob:secret@myhost:9999/foo?bar=baz", s)
+
+	u, err = url.Parse("postgres://bob:secret@myhost:1234/foo?host=new&port=9999")
+	require.NoError(t, err)
+	s = normalizePostgresURL(u)
+	require.Equal(t, "postgres://bob:secret@:9999/foo?host=new", s)
+
+	u, err = url.Parse("postgres://bob:secret@myhost:1234/foo?host=/var/run/postgresql")
+	require.NoError(t, err)
+	s = normalizePostgresURL(u)
+	require.Equal(t, "postgres://bob:secret@:1234/foo?host=%2Fvar%2Frun%2Fpostgresql", s)
+}
+
+func TestNormalizePostgresURLSocketParam(t *testing.T) {
+	u, err := url.Parse("postgres://bob:secret@localhost/foo?socket=/var/run/postgresql")
+	require.NoError(t, err)
+	s := normalizePostgresURL(u)
+	require.Equal(t, "postgres://bob:secret@:5432/foo?host=%2Fvar%2Frun%2Fpostgresql", s)
+
+	u, err = url.Parse("postgres:///foo?socket=/var/run/postgresql")
+	require.NoError(t, err)
+	s = normalizePostgresURL(u)
+	require.Equal(t, "postgres://:5432/foo?host=%2Fvar%2Frun%2Fpostgresql", s)
+}
+
 func TestPostgresCreateDropDatabase(t *testing.T) {
 	drv := PostgresDriver{}
 	u := postgresTestURL(t)