Utility user¶
Percona Server for MySQL has implemented ability to have a MySQL user who has system access to do administrative tasks but limited access to user schema. This feature is especially useful to those operating MySQL As A Service.
This user has a mixed and special scope of abilities and protection:
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Utility user does not appear in the mysql.user table and can not be modified by any other user, including root.
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Utility user does not appear in INFORMATION_SCHEMA.USER_STATISTICS, INFORMATION_SCHEMA.CLIENT_STATISTICS or THREAD_STATISTICS tables or in any performance_schema tables.
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Utility user’s queries may appear in the general and slow logs.
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Utility user does not have the ability create, modify, delete or see any schemas or data not specified, except for information_schema.
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Utility user may modify all visible, non-read-only system variables (see expanded_option_modifiers functionality).
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Utility user may see, create, modify and delete other system users only if given access to the mysql schema.
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Regular users may be granted proxy rights to the utility user but attempts to impersonate the utility user fail. The utility user may not be granted proxy rights on any regular user.
For example, GRANT PROXY ON utility_user TO regular_user; does not fail, but any actual attempt to impersonate as the utility user fails.
GRANT PROXY ON regular_user TO utility_user; fails when utility_user is an exact match or is more specific than than the utility user specified.
At server start, the server notes in the log output that the utility user exists and the schemas that the utility user can access.
System variables¶
In order to have the ability for a special type of MySQL user, which will have a very limited and special amount of control over the system and can not be see or modified by any other user including the root user, three new options have been added.
utility_user¶
| Option | Description |
|---|---|
| Command Line: | Yes |
| Config file | utility_user=<user@host> |
| Scope: | Global |
| Dynamic: | No |
| Data type | String |
| Default | NULL |
Specifies a MySQL user that will be added to the internal list of users and recognized as the utility user.
Option utility_user specifies the user which the system creates and recognizes as the utility user. The host in the utility user specification follows conventions described in the MySQL manual. For example, the conventions allow wildcards and IP masks. Anonymous user names are not permitted to be used for the utility user name.
This user must not be an exact match to any other user that exists in the mysql.user table. If the server detects that the user specified with this option exactly matches any user within the mysql.user table on start up, the server reports an error and exits gracefully.
If host name wildcards are used and a more specific user specification is identified on start up, the server reports a warning and continues.
Error message
utility_user=frank@% and [frank@localhost](mailto:frank@localhost) exists within the mysql.user table.
If a client attempts to create a MySQL user that matches this user specification exactly or if host name wildcards are used for the utility user and the user being created has the same name and a more specific host, the creation attempt fails with an error.
Error message
utility_user=frank@% and CREATE USER [‘frank@localhost](mailto:'frank@localhost)’;
As a result of these requirements, it is strongly recommended that a very unique user name and reasonably specific host be used.
Verify the script or tools test they are running within the correct user by executing SELECT CURRENT_USER() and comparing the result against the known utility user.
utility_user_password¶
| Option | Description |
|---|---|
| Command Line: | Yes |
| Config file | utility_user_password=password |
| Scope: | Global |
| Dynamic: | No |
| Data type | String |
| Default | NULL |
Specifies the password required for the utility user.
Option utility_user_password specifies the password for the utility user and must be specified or the server exits with an error.
Utility user password
utility_user_password=Passw0rD
utility_user_schema_access¶
| Option | Description |
|---|---|
| Command Line: | Yes |
| Config file | utility_user_schema_access=schema,schema,schema |
| Scope: | Global |
| Dynamic: | No |
| Data type | String |
| Default | NULL |
Specifies the schemas that the utility user has access to in a comma delimited list.
Option utility_user_schema_access specifies the name(s) of the schema(s) that the utility user will have access to read write and modify. If a particular schema named here does not exist on start up it will be ignored. If a schema by the name of any of those listed in this option is created after the server is started, the utility user will have full access to it.
Utility user schema access
utility_user_schema_access=schema1,schema2,schema3
utility_user_privileges¶
| Option | Description |
|---|---|
| Command Line: | Yes |
| Config file | utility_user_privileges=privilege1,privilege2,privilege3 |
| Scope: | Global |
| Dynamic: | No |
| Data type | String |
| Default | NULL |
This variable can be used to specify a comma-separated list of extra access privileges to grant to the utility user. Supported values for the privileges list are: SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, SHUTDOWN, PROCESS, FILE, GRANT, REFERENCES, INDEX, ALTER, SHOW DATABASES, SUPER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, REPLICATION SLAVE, REPLICATION CLIENT, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, CREATE USER, EVENT, TRIGGER, CREATE TABLESPACE
Option utility-user-privileges allows a comma-separated list of extra access privileges to grant to the utility user.
Utility user privileges
utility-user-privileges =”CREATE,DROP,LOCK TABLES”;
utility_user_dynamic_privileges¶
| Option | Description |
|---|---|
| Command Line: | Yes |
| Config file | utility_user_dynamic_privileges=privilege1,privilege2,privilege3 |
| Scope: | Global |
| Dynamic: | No |
| Data type | String |
| Default | NULL |
This variable allows a comma-separated list of extra access dynamic privileges to grant to the utility user. The supported values for the dynamic privileges are:
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APPLICATION_PASSWORD_ADMIN
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AUDIT_ADMIN
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BACKUP_ADMIN
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BINLOG_ADMIN
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BINLOG_ENCRYPTION_ADMIN
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CLONE_ADMIN
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CONNECTION_ADMIN
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ENCRYPTION_KEY_ADMIN
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FIREWALL_ADMIN
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FIREWALL_USER
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GROUP_REPLICATION_ADMIN
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INNODB_REDO_LOG_ARCHIVE
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NDB_STORED_USER
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PERSIST_RO_VARIABLES_ADMIN
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REPLICATION_APPLIER
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REPLICATION_SLAVE_ADMIN
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RESOURCE_GROUP_ADMIN
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RESOURCE_GROUP_USER
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ROLE_ADMIN
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SESSION_VARIABLES_ADMIN
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SET_USER_ID
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SHOW_ROUTINE
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SYSTEM_USER
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SYSTEM_VARIABLES_ADMIN
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TABLE_ENCRYPTION_ADMIN
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VERSION_TOKEN_ADMIN
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XA_RECOVER_ADMIN
Other dynamic privileges may be defined by plugins.
Option utility_user_dynamic_privileges allows a comma-separated list of extra-access dynamic privileges to grant to the utility user.
Utility user dynamic privileges
utility_user_dynamic_privileges =”SYSTEM_USER,AUDIT_ADMIN”;
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