Hi We encountered an unfortunate case of $SUBJECT the other day where it would have been preferable to catch the error before rather than after pg_basebackup ran.
I can't think of any practical reason why pg_basebackup would ever need to be run as root; we disallow that for initdb, pg_ctl and pg_upgrade, so it seems reasonable to do the same for pg_basebackup. Trivial patch attached, which as with the other cases will allow only the --help/--version options to be executed as root, otherwise nothing else. The patch doesn't update the pg_basebackup documentation page; we don't mention it in the pg_ctl and pg_upgrade pages either and it doesn't seem particularly important to mention it explicitly. I'll add this to the March CF. Regards Ian Barwick -- Ian Barwick https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c index 238b671f7a..f25a137114 100644 --- a/src/bin/pg_basebackup/pg_basebackup.c +++ b/src/bin/pg_basebackup/pg_basebackup.c @@ -2077,6 +2077,21 @@ main(int argc, char **argv) } } + /* + * Disallow running as root, as PostgreSQL will be unable to start + * with root-owned files. + */ + #ifndef WIN32 + if (geteuid() == 0) /* 0 is root's uid */ + { + pg_log_error("cannot be run as root"); + fprintf(stderr, + _("Please log in (using, e.g., \"su\") as the (unprivileged) user that will\n" + "own the server process.\n")); + exit(1); + } +#endif + atexit(cleanup_directories_atexit); while ((c = getopt_long(argc, argv, "CD:F:r:RS:T:X:l:nNzZ:d:c:h:p:U:s:wWkvP",