openGauss每日一练第 19 天 | 用户和角色管理

学习目标
掌握openGauss的用户和角色管理。

课程学习
使用create user创建的用户与使用create role创建的用户的区别在于，前者可以直接连接登录数据库，而使用create role创建的用户不能直接登录到数据库。必须添加LOGIN权限后，才能登录到数据库管理系统。
删除用户，首先需要将用户拥有的数据库对象转移或者删除。

课程作业
1、创建test10_tbs的表空间，在这个表空间中创建数据库testdb10

root@modb:~# su - omm
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
omm=# create tablespace test10_tbs relative location 'tablespace/test10tbs';
CREATE TABLESPACE
omm=# create database testdb10 with tablespace=test10_tbs;
omm=# CREATE DATABASE

2、使用create user创建用户user10，登录数据库testdb10，创建测试表t1和t2

omm=# create user user10 identified by 'test@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
omm=# CREATE ROLE

omm=# grant all on database testdb10 to user10;
GRANT

omm=# alter user user10 sysadmin;
ALTER ROLE
omm=# \q
omm@modb:~$ gsql -d testdb10 -U user10 -W test@1234 -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

testdb10=> create table t1(id int);
CREATE TABLE
testdb10=> create table t2(id int);
CREATE TABLE

3、使用create role创建角色role10，登录数据库testdb10

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# create role role10 identified by 'role@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# grant all on database testdb10 to role10;
GRANT
omm=# \q

omm@modb:~$ gsql -d testdb10 -U role10 -W role@1234 -r
gsql: FATAL:  role "role10" is not permitted to login

原因：
由于数据库用户role10 是使用create role语句创建的，目前还不被允许登录到openGauss数据库管理系统。

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# alter user role10 login;
ALTER ROLE
omm=# \q
omm@modb:~$ gsql -d test10 -U role10 -W role@1234 -r
gsql: FATAL:  database "test10" does not exist
omm@modb:~$ gsql -d testdb10 -U role10 -W role@1234 -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

4、将表t1直接删除，将前面创建的表空间和数据库、表t2转给role10，删除用户user10

删除用户，首先需要将用户拥有的数据库对象转移或者删除，回收权限。

root@modb:~# su - omm
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# \c testdb10 user10
Password for user user10: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "testdb10" as user "user10".
testdb10=> drop table t1;
DROP TABLE

testdb10=> reassign owned by user10 to role10;
REASSIGN OWNED
testdb10=> \dt
                         List of relations
 Schema | Name | Type  | Owner  |             Storage              
--------+------+-------+--------+----------------------------------
 public | t2   | table | role10 | {orientation=row,compression=no}
(1 row)

testdb10=> \q

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# alter database testdb10 owner to role10;
ALTER DATABASE
omm=# alter tablespace test10_tbs owner to role10;
ALTER TABLESPACE
omm=# revoke all on database testdb10 from user10;
REVOKE
omm=# drop user user10;
DROP ROLE
omm=# \du
                                                              List of roles
 Role name |                                                    Attributes                  
                                  | Member of 
-----------+--------------------------------------------------------------------------------
----------------------------------+-----------
 gaussdb   | Sysadmin                                                                       
                                  | {}
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, 
Operatoradmin, Policyadmin, UseFT | {}
 role10    |                                                                                
                                  | {}

5、最后删除role10

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# create user dhr identified by 'dhr@1234';
NOTICE:  The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# alter database testdb10 owner to dhr;
ALTER DATABASE
omm=# alter tablespace test10_tbs owner to dhr;
ALTER TABLESPACE
omm=# revoke all on databaes testdb10 from role10;
ERROR:  syntax error at or near "testdb10"
LINE 1: revoke all on databaes testdb10 from role10;
                               ^
omm=# revoke all on database testdb10 from role10;
REVOKE
omm=# \c testdb10 role10
Password for user role10: 
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "testdb10" as user "role10".
testdb10=> drop table t2;
DROP TABLE
testdb10=> \q
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

omm=# drop role role10;
DROP ROLE
omm=# \du
                                                              List of roles
 Role name |                                                    Attributes                  
                                  | Member of 
-----------+--------------------------------------------------------------------------------
----------------------------------+-----------
 dhr       |                                                                                
                                  | {}
 gaussdb   | Sysadmin                                                                       
                                  | {}
 omm       | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, 
Operatoradmin, Policyadmin, UseFT | {}