Surface error and simplify ListDatabases function (#143)

* Surface error and simplify ListDatabases function

* Fix lint

Author: davissp14

internal/flypg/admin/admin.go

@@ -74,13 +74,14 @@ func ChangePassword(ctx context.Context, pg *pgx.Conn, username, password string
 
 func CreateDatabaseWithOwner(ctx context.Context, pg *pgx.Conn, name, owner string) error {
 	dbInfo, err := FindDatabase(ctx, pg, name)
-	if err != nil && err != pgx.ErrNoRows {
+	if err != nil {
 		return err
 	}
-	// Database already exists.
+
 	if dbInfo != nil {
 		return nil
 	}
+
 	sql := fmt.Sprintf("CREATE DATABASE %s OWNER %s;", name, owner)
 	_, err = pg.Exec(ctx, sql)
 
@@ -89,7 +90,7 @@ func CreateDatabaseWithOwner(ctx context.Context, pg *pgx.Conn, name, owner stri
 
 func CreateDatabase(ctx context.Context, pg *pgx.Conn, name string) error {
 	dbInfo, err := FindDatabase(ctx, pg, name)
-	if err != nil && err != pgx.ErrNoRows {
+	if err != nil {
 		return err
 	}
 	// Database already exists.
@@ -197,7 +198,7 @@ func ListDatabases(ctx context.Context, pg *pgx.Conn) ([]DbInfo, error) {
 	}
 	defer rows.Close()
 
-	values := []DbInfo{}
+	var values []DbInfo
 
 	for rows.Next() {
 		di := DbInfo{}
@@ -210,23 +211,19 @@ func ListDatabases(ctx context.Context, pg *pgx.Conn) ([]DbInfo, error) {
 	return values, nil
 }
 
-func FindDatabase(ctx context.Context, pg *pgx.Conn, name string) (*DbInfo, error) {
-	sql := `
-	SELECT
-		datname,
-		(SELECT array_agg(u.usename::text order by u.usename) FROM pg_user u WHERE has_database_privilege(u.usename, d.datname, 'CONNECT')) as allowed_users
-	FROM pg_database d WHERE d.datname='%s';
-	`
-
-	sql = fmt.Sprintf(sql, name)
-	row := pg.QueryRow(ctx, sql)
-
-	db := new(DbInfo)
-	if err := row.Scan(&db.Name, &db.Users); err != nil {
+func FindDatabase(ctx context.Context, conn *pgx.Conn, name string) (*DbInfo, error) {
+	dbs, err := ListDatabases(ctx, conn)
+	if err != nil {
 		return nil, err
 	}
 
-	return db, nil
+	for _, db := range dbs {
+		if db.Name == name {
+			return &db, nil
+		}
+	}
+
+	return nil, nil
 }
 
 type UserInfo struct {
@@ -260,7 +257,7 @@ func ListUsers(ctx context.Context, pg *pgx.Conn) ([]UserInfo, error) {
 	}
 	defer rows.Close()
 
-	values := []UserInfo{}
+	var values []UserInfo
 
 	for rows.Next() {
 		ui := UserInfo{}

internal/flypg/node.go

@@ -329,7 +329,7 @@ func (n *Node) PostInit(ctx context.Context) error {
 
 			// Setup repmgr database and extension
 			if err := n.RepMgr.enable(ctx, conn); err != nil {
-				fmt.Printf("failed to setup repmgr: %s\n", err)
+				return fmt.Errorf("failed to enable repmgr: %s", err)
 			}
 
 			// Register ourself as the primary