From 7f6772317b4a4f9d30c25d1853571fca6d834f0c Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Fri, 28 Jan 2022 12:26:33 -0500 Subject: [PATCH] Adjust server-side backup to depend on pg_write_server_files. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit I had made it depend on superuser, but that seems clearly inferior. Also document the permissions requirement in the straming replication protocol section of the documentation, rather than only in the section having to do with pg_basebackup. Idea and patch from Dagfinn Ilmari Mannsåker. Discussion: http://postgr.es/m/87bkzw160u.fsf@wibble.ilmari.org --- doc/src/sgml/protocol.sgml | 5 +++++ doc/src/sgml/ref/pg_basebackup.sgml | 3 ++- src/backend/replication/basebackup_server.c | 6 ++++-- 3 files changed, 11 insertions(+), 3 deletions(-) diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml index 68908dcb7b3..24e93f9b284 100644 --- a/doc/src/sgml/protocol.sgml +++ b/doc/src/sgml/protocol.sgml @@ -2647,6 +2647,11 @@ The commands accepted in replication mode are: blackhole, the backup data is not sent anywhere; it is simply discarded. + + + The server target requires superuser privilege or + being granted the pg_write_server_files role. + diff --git a/doc/src/sgml/ref/pg_basebackup.sgml b/doc/src/sgml/ref/pg_basebackup.sgml index dfd8aebc9a3..1546f10c0d9 100644 --- a/doc/src/sgml/ref/pg_basebackup.sgml +++ b/doc/src/sgml/ref/pg_basebackup.sgml @@ -237,7 +237,8 @@ PostgreSQL documentation server:/some/path, the backup will be stored on the machine where the server is running in the /some/path directory. Storing a backup on the - server requires superuser privileges. If the target is set to + server requires superuser privileges or being granted the + pg_write_server_files role. If the target is set to blackhole, the contents are discarded and not stored anywhere. This should only be used for testing purposes, as you will not end up with an actual backup. diff --git a/src/backend/replication/basebackup_server.c b/src/backend/replication/basebackup_server.c index ce1b7b47977..18b0e11d903 100644 --- a/src/backend/replication/basebackup_server.c +++ b/src/backend/replication/basebackup_server.c @@ -10,10 +10,12 @@ */ #include "postgres.h" +#include "catalog/pg_authid.h" #include "miscadmin.h" #include "replication/basebackup.h" #include "replication/basebackup_sink.h" #include "storage/fd.h" +#include "utils/acl.h" #include "utils/timestamp.h" #include "utils/wait_event.h" @@ -65,10 +67,10 @@ bbsink_server_new(bbsink *next, char *pathname) sink->base.bbs_next = next; /* Replication permission is not sufficient in this case. */ - if (!superuser()) + if (!is_member_of_role(GetUserId(), ROLE_PG_WRITE_SERVER_FILES)) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), - errmsg("must be superuser to create server backup"))); + errmsg("must be superuser or a member of the pg_write_server_files role to create server backup"))); /* * It's not a good idea to store your backups in the same directory that