MDEV-23630: mysqldump logically dump system table information

[grooverdan]

Add --system={all, users, plugins, udf, servers, stats, timezones}

This will dump system information from the server in
a logical form like

• CREATE USER
• GRANT
• CREATE ROLE
• CREATE SERVER
• INSTALL PLUGIN
• CREATE FUNCTION

"stats" is the innodb statistics tables or EITS and
these are dumped as INSERT/REPLACE INTO statements
without recreating the table.

"timezones" is the collection of timezone tables
which are important to transfer to generate identical
results on restoration.

Two other options have an effect on the SQL generated by
--system=all. These are mutually exclusive of each other.

• --replace
• --insert-ignore

--replace will include "OR REPLACE" into the logical form
like 'CREATE OR REPLACE USER ...'

--insert-ignore uses the construct " IF NOT EXISTS" where
supported in the logical syntax.

[an3l]

Thanks @grooverdan ,
Additional to this I would update help:

Dump system tables as portable SQL. Any combination of:.. [to name is allowed]

And if you see the help for

character-sets-dir                (No default value)

Your system is empty -> should write (No default value ) too.
Also noted that for 10.2 default anonymous user we get this:

user - anonymous:

mysqldump: Couldn't execute 'SELECT CONCAT(QUOTE(u.user), '@', QUOTE(u.Host)) AS u FROM mysql.user u  /*!80001 LEFT JOIN mysql.role_edges e ON u.user=e.from_user AND u.host=e.from_host          WHERE e.from_user IS NULL */ /*M!100005 WHERE is_role='N' */': SELECT command denied to user ''@'localhost' for table 'user' (1142)

MySQL error code 1142 (ER_TABLEACCESS_DENIED_ERROR): %-.100T command denied to user '%s'@'%s' for table '%-.192s'

[an3l]

Why not having udfs in plural too? Indentation 80 chars + 2 spaces (seems here are 4).

[grooverdan]

I've brought back a lot of the strings to 80 chars or less. There's a few exceptions on longer SQL that I've just tried to keep readable while following indenting rules.

[an3l]

all_udfs

[an3l]

So here for specific options you are ignoring some tables.
https://mariadb.com/kb/en/mysqlglobal_priv-table/ in 10.4 started, it shouldn't be there for 10.2, right?
Also it is replacing user table, user is still there but is a view.

[grooverdan]

Its there so a), the merge up branches works. b) so if a user happens to use a mysqldump-10.2 on mariadb-server-10.4 they don't get the global_privs table dumped along with all the create user,role; grant that overwrites the same information.

Whether user is a table or view, it needs to be ignored from the dump.

This is important when mysqldump --system=all --all-databases is used, or if mysql database is explicitly listed as the dump database,

[an3l]

Same here:
https://mariadb.com/kb/en/mysqltables_priv-table/
It is tables_priv

[an3l]

columns_priv

[grooverdan]

Thanks @grooverdan ,
Additional to this I would update help:

Dump system tables as portable SQL. Any combination of:.. [to name is allowed]

I see:

  --system=name       Dump system tables as portable SQL. Any combination of: 
                      all, users, plugins, udfs, servers, stats, timezones

With the below patch I could get:

  --ssl-crl=name      Certificate revocation list (implies --ssl).
  --ssl-crlpath=name  Certificate revocation list path (implies --ssl).
  --ssl-verify-server-cert 
                      Verify server's "Common Name" in its cert against
                      hostname used when connecting. This option is disabled by
                      default.
  --system=name       Dump system tables as portable SQL. Any combination of
                      [for name]: all, users, plugins, udfs, servers, stats, 
                      timezones

It looks odd because all the other =name values make no reference to name in the help.

diff --git a/mysys/my_getopt.c b/mysys/my_getopt.c
index 13d0d7c240e..85a34a77b62 100644
--- a/mysys/my_getopt.c
+++ b/mysys/my_getopt.c
@@ -1522,7 +1522,7 @@ void my_print_help(const struct my_option *options)
         count= optp->typelib->count;
         break;
       case GET_SET: 
-        typelib_help= ". Any combination of: ";
+        typelib_help= ". Any combination of [for name]: ";
         count= optp->typelib->count;
         break;
       case GET_FLAGSET:

And if you see the help for

character-sets-dir                (No default value)

This would be a global change and would affect every other client tool and possibly some of the server parsing. I'm not sure I want to touch this.

Your system is empty -> should write (No default value ) too.

Is Empty set ok?

ssl-verify-server-cert            FALSE
system                            (Empty set)

Also noted that for 10.2 default anonymous user we get this:

user - anonymous:

mysqldump: Couldn't execute 'SELECT CONCAT(QUOTE(u.user), '@', QUOTE(u.Host)) AS u FROM mysql.user u  /*!80001 LEFT JOIN mysql.role_edges e ON u.user=e.from_user AND u.host=e.from_host          WHERE e.from_user IS NULL */ /*M!100005 WHERE is_role='N' */': SELECT command denied to user ''@'localhost' for table 'user' (1142)

MySQL error code 1142 (ER_TABLEACCESS_DENIED_ERROR): %-.100T command denied to user '%s'@'%s' for table '%-.192s'

There's no other privilege checks currently. To address this a generic error saying what privs are require would be needed and we'd need to do this for all the existing options.