How does privileges for new relations in PostgreSQL work?
Steps:
Create DB (from user postgres) and connect to it
CREATE DATABASE test;
\c test
Create user site with some privileges
CREATE USER site NOCREATEDB NOINHERIT;
GRANT SELECT, UPDATE, INSERT, DELETE, TRUNCATE, REFERENCES ON ALL TABLES IN SCHEMA public TO site;
GRANT USAGE, SELECT ON ALL SEQUENCES IN SCHEMA public TO site;
Change default privileges for user site
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT, UPDATE, INSERT, DELETE, TRUNCATE, REFERENCES ON TABLES TO site;
Create user migration with all privileges
CREATE USER migration NOCREATEDB NOINHERIT;
GRANT ALL PRIVILEGES ON DATABASE test TO migration;
Connect to DB from user migration and create table
CREATE TABLE test (id serial);
Connect to DB from user site and select data from created table
SELECT * FROM test;
ERROR: permission denied for relation test
But if I create table from user postgres, all work fine!
Why default privileges didn't work in this case? How can I grant permissions for new tables for user site?
ALTER DEFAULT PRIVILEGES only affects objects created by the user specified in the FOR ROLE clause. If you omit this clause, it only applies to the user running the command (in your case, postgres).
You want ALTER DEFAULT PRIVILEGES FOR USER migration ... instead.
Related
I am running this command
gcloud sql import sql db1 gs://mybucket/sqldumpfile.gz --database=mydb1
to import a database snapshot into a new database. Before running it, I recreated the same users I had in the source database, using Cloud Console. However, I keep on getting this error:
ERROR: must be member of role "postgres"
STATEMENT: ALTER DEFAULT PRIVILEGES FOR ROLE postgres IN SCHEMA public GRANT SELECT ON TABLES TO user1;
I am not sure what to do and which user must be "member of role postgres".
Any advice is appreciated
To grant default privileges for user2, use the FOR ROLE clause:
ALTER DEFAULT PRIVILEGES FOR USER <user-1> IN SCHEMA <user-1> GRANT INSERT, UPDATE, DELETE ON TABLES TO <user-2>;
ALTER DEFAULT PRIVILEGES FOR USER <user-1> IN SCHEMA <user-1> GRANT SELECT ON TABLES TO <user-2>;
You need to grant the rights from the user-1 which is creating the table, So whenever the user-1 creates a table, it will grant the SELECT rights for the user-2.
For more information refer to this document.
I created new role named "support" in my PostgreSQL. Now I need grant "READ ONLY" permissions for this role an ALL exists databases/tables.
Also I need automatically granted same permissions on each DB that will created in future.
I unsuccessfully tried next queries for grant permissions in new databases (Can not select from new database tables ):
ALTER DEFAULT PRIVILEGES FOR ROLE support GRANT SELECT ON TABLES TO PUBLIC;
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES to support;
ALTER DEFAULT PRIVILEGES allows you to set the privileges that will be
applied to objects created in the future. (It does not affect
privileges assigned to already-existing objects.)
I am setting up a Postgres DB (AWS/RDS) with multiple schemas and want to have granular access control.
Each schema correlates to an application. Typically an application will have a "write" user (INSERT, UPDATE, DELETE etc.), but some applications only needs to read (SELECT) from different schemas.
Inspired by this AWS blog: https://aws.amazon.com/blogs/database/managing-postgresql-users-and-roles/
I face problems with "permission denied" for my readusers querying tables created by writeusers, even though I ALTER DEFAULT PRIVILEGES:
ALTER DEFAULT PRIVILEGES IN SCHEMA someschema GRANT SELECT ON TABLES TO some_read_role;
Steps to reproduce:
Create AWS RDS postgres (10.6) instance with masteruser postgres
(DB postgres) As user postgres:
CREATE DATABASE somedb LC_COLLATE 'da_DK.utf8' LC_CTYPE 'da_DK.utf8' ENCODING 'UTF8' TEMPLATE template0;
(DB somedb) As user postgres:
REVOKE ALL ON DATABASE somedb FROM PUBLIC;
CREATE SCHEMA clients;
CREATE ROLE clients_read_role;
GRANT CONNECT ON DATABASE somedb TO clients_read_role;
CREATE ROLE clients_write_role;
GRANT CONNECT ON DATABASE somedb TO clients_write_role;
GRANT USAGE ON SCHEMA clients TO clients_read_role;
GRANT SELECT ON ALL TABLES IN SCHEMA clients TO clients_read_role;
ALTER DEFAULT PRIVILEGES IN SCHEMA clients GRANT SELECT ON TABLES TO clients_read_role;
GRANT SELECT ON ALL SEQUENCES IN SCHEMA clients TO clients_read_role;
ALTER DEFAULT PRIVILEGES IN SCHEMA clients GRANT SELECT ON SEQUENCES TO clients_read_role;
GRANT USAGE, CREATE ON SCHEMA clients TO clients_write_role;
GRANT SELECT, INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA clients TO clients_write_role;
ALTER DEFAULT PRIVILEGES IN SCHEMA clients GRANT SELECT, INSERT, UPDATE, DELETE ON TABLES TO clients_write_role;
GRANT USAGE ON ALL SEQUENCES IN SCHEMA clients TO clients_write_role;
ALTER DEFAULT PRIVILEGES IN SCHEMA clients GRANT USAGE ON SEQUENCES TO clients_write_role;
(DB somedb) As user postgres:
CREATE USER clients_read WITH PASSWORD 'xxx';
GRANT clients_read_role TO clients_read;
CREATE USER clients_write WITH PASSWORD 'yyy';
GRANT clients_write_role TO clients_write;
(DB somedb) As user clients_write (via LiquiBase):
CREATE TABLE clients.sometable
(
id serial primary key,
name varchar(50) not null
);
(DB somedb) as user clients_read:
SELECT * FROM clients.sometable;
[42501] ERROR: permission denied for relation sometable
From the docs:
You can change default privileges only for objects that will be
created by yourself or by roles that you are a member of.
In other words, running ALTER DEFAULT PRIVILEGES as user postgres only affects tables created by postgres.
To change the defaults for another user's tables, you need to specify which user:
ALTER DEFAULT PRIVILEGES FOR ROLE clients_write ...
Note that the defaults are not inherited, so the target role is clients_write (i.e. the user actually running the CREATE TABLE command, who will become the new table's owner). Defaults for clients_write_role will have no effect unless your users SET ROLE clients_write_role; before creating a table.
I'd like to create a user in PostgreSQL that can only do SELECTs from a particular database. In MySQL the command would be:
GRANT SELECT ON mydb.* TO 'xxx'#'%' IDENTIFIED BY 'yyy';
What is the equivalent command or series of commands in PostgreSQL?
I tried...
postgres=# CREATE ROLE xxx LOGIN PASSWORD 'yyy';
postgres=# GRANT SELECT ON DATABASE mydb TO xxx;
But it appears that the only things you can grant on a database are CREATE, CONNECT, TEMPORARY, and TEMP.
Grant usage/select to a single table
If you only grant CONNECT to a database, the user can connect but has no other privileges. You have to grant USAGE on namespaces (schemas) and SELECT on tables and views individually like so:
GRANT CONNECT ON DATABASE mydb TO xxx;
-- This assumes you're actually connected to mydb..
GRANT USAGE ON SCHEMA public TO xxx;
GRANT SELECT ON mytable TO xxx;
Multiple tables/views (PostgreSQL 9.0+)
In the latest versions of PostgreSQL, you can grant permissions on all tables/views/etc in the schema using a single command rather than having to type them one by one:
GRANT SELECT ON ALL TABLES IN SCHEMA public TO xxx;
This only affects tables that have already been created. More powerfully, you can automatically have default roles assigned to new objects in future:
ALTER DEFAULT PRIVILEGES IN SCHEMA public
GRANT SELECT ON TABLES TO xxx;
Note that by default this will only affect objects (tables) created by the user that issued this command: although it can also be set on any role that the issuing user is a member of. However, you don't pick up default privileges for all roles you're a member of when creating new objects... so there's still some faffing around. If you adopt the approach that a database has an owning role, and schema changes are performed as that owning role, then you should assign default privileges to that owning role. IMHO this is all a bit confusing and you may need to experiment to come up with a functional workflow.
Multiple tables/views (PostgreSQL versions before 9.0)
To avoid errors in lengthy, multi-table changes, it is recommended to use the following 'automatic' process to generate the required GRANT SELECT to each table/view:
SELECT 'GRANT SELECT ON ' || relname || ' TO xxx;'
FROM pg_class JOIN pg_namespace ON pg_namespace.oid = pg_class.relnamespace
WHERE nspname = 'public' AND relkind IN ('r', 'v', 'S');
This should output the relevant GRANT commands to GRANT SELECT on all tables, views, and sequences in public, for copy-n-paste love. Naturally, this will only be applied to tables that have already been created.
Reference taken from this blog:
Script to Create Read-Only user:
CREATE ROLE Read_Only_User WITH LOGIN PASSWORD 'Test1234'
NOSUPERUSER INHERIT NOCREATEDB NOCREATEROLE NOREPLICATION VALID UNTIL 'infinity';
\connect YourDatabaseName;
Assign permission to this read-only user:
GRANT CONNECT ON DATABASE YourDatabaseName TO Read_Only_User;
GRANT USAGE ON SCHEMA public TO Read_Only_User;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO Read_Only_User;
GRANT SELECT ON ALL SEQUENCES IN SCHEMA public TO Read_Only_User;
REVOKE CREATE ON SCHEMA public FROM PUBLIC;
Assign permissions to read all newly tables created in the future
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO Read_Only_User;
From PostgreSQL v14 on, you can do that simply by granting the predefined pg_read_all_data role:
GRANT pg_read_all_data TO xxx;
Do note that PostgreSQL 9.0 (today in beta testing) will have a simple way to do that:
test=> GRANT SELECT ON ALL TABLES IN SCHEMA public TO joeuser;
Here is the best way I've found to add read-only users (using PostgreSQL 9.0 or newer):
$ sudo -upostgres psql postgres
postgres=# CREATE ROLE readonly WITH LOGIN ENCRYPTED PASSWORD '<USE_A_NICE_STRONG_PASSWORD_PLEASE';
postgres=# GRANT SELECT ON ALL TABLES IN SCHEMA public TO readonly;
Then log in to all related machines (master + read-slave(s)/hot-standby(s), etc..) and run:
$ echo "hostssl <PUT_DBNAME_HERE> <PUT_READONLY_USERNAME_HERE> 0.0.0.0/0 md5" | sudo tee -a /etc/postgresql/9.2/main/pg_hba.conf
$ sudo service postgresql reload
By default new users will have permission to create tables. If you are planning to create a read-only user, this is probably not what you want.
To create a true read-only user with PostgreSQL 9.0+, run the following steps:
# This will prevent default users from creating tables
REVOKE CREATE ON SCHEMA public FROM public;
# If you want to grant a write user permission to create tables
# note that superusers will always be able to create tables anyway
GRANT CREATE ON SCHEMA public to writeuser;
# Now create the read-only user
CREATE ROLE readonlyuser WITH LOGIN ENCRYPTED PASSWORD 'strongpassword';
GRANT SELECT ON ALL TABLES IN SCHEMA public TO readonlyuser;
If your read-only user doesn't have permission to list tables (i.e. \d returns no results), it's probably because you don't have USAGE permissions for the schema. USAGE is a permission that allows users to actually use the permissions they have been assigned. What's the point of this? I'm not sure. To fix:
# You can either grant USAGE to everyone
GRANT USAGE ON SCHEMA public TO public;
# Or grant it just to your read only user
GRANT USAGE ON SCHEMA public TO readonlyuser;
I’ve created a convenient script for that; pg_grant_read_to_db.sh. This script grants read-only privileges to a specified role on all tables, views and sequences in a database schema and sets them as default.
I read trough all the possible solutions, which are all fine, if you remember to connect to the database before you grant the things ;) Thanks anyway to all other solutions!!!
user#server:~$ sudo su - postgres
create psql user:
postgres#server:~$ createuser --interactive
Enter name of role to add: readonly
Shall the new role be a superuser? (y/n) n
Shall the new role be allowed to create databases? (y/n) n
Shall the new role be allowed to create more new roles? (y/n) n
start psql cli and set a password for the created user:
postgres#server:~$ psql
psql (10.6 (Ubuntu 10.6-0ubuntu0.18.04.1), server 9.5.14)
Type "help" for help.
postgres=# alter user readonly with password 'readonly';
ALTER ROLE
connect to the target database:
postgres=# \c target_database
psql (10.6 (Ubuntu 10.6-0ubuntu0.18.04.1), server 9.5.14)
You are now connected to database "target_database" as user "postgres".
grant all the needed privileges:
target_database=# GRANT CONNECT ON DATABASE target_database TO readonly;
GRANT
target_database=# GRANT USAGE ON SCHEMA public TO readonly ;
GRANT
target_database=# GRANT SELECT ON ALL TABLES IN SCHEMA public TO readonly ;
GRANT
alter default privileges for targets db public shema:
target_database=# ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO readonly;
ALTER DEFAULT PRIVILEGES
If your database is in the public schema, it is easy (this assumes you have already created the readonlyuser)
db=> GRANT SELECT ON ALL TABLES IN SCHEMA public to readonlyuser;
GRANT
db=> GRANT CONNECT ON DATABASE mydatabase to readonlyuser;
GRANT
db=> GRANT SELECT ON ALL SEQUENCES IN SCHEMA public to readonlyuser;
GRANT
If your database is using customschema, execute the above but add one more command:
db=> ALTER USER readonlyuser SET search_path=customschema, public;
ALTER ROLE
The not straightforward way of doing it would be granting select on each table of the database:
postgres=# grant select on db_name.table_name to read_only_user;
You could automate that by generating your grant statements from the database metadata.
Taken from a link posted in response to despesz' link.
Postgres 9.x appears to have the capability to do what is requested. See the Grant On Database Objects paragraph of:
http://www.postgresql.org/docs/current/interactive/sql-grant.html
Where it says: "There is also an option to grant privileges on all objects of the same type within one or more schemas. This functionality is currently supported only for tables, sequences, and functions (but note that ALL TABLES is considered to include views and foreign tables)."
This page also discusses use of ROLEs and a PRIVILEGE called "ALL PRIVILEGES".
Also present is information about how GRANT functionalities compare to SQL standards.
CREATE USER username SUPERUSER password 'userpass';
ALTER USER username set default_transaction_read_only = on;
I'd like to create a user in PostgreSQL that can only do SELECTs from a particular database. In MySQL the command would be:
GRANT SELECT ON mydb.* TO 'xxx'#'%' IDENTIFIED BY 'yyy';
What is the equivalent command or series of commands in PostgreSQL?
I tried...
postgres=# CREATE ROLE xxx LOGIN PASSWORD 'yyy';
postgres=# GRANT SELECT ON DATABASE mydb TO xxx;
But it appears that the only things you can grant on a database are CREATE, CONNECT, TEMPORARY, and TEMP.
Grant usage/select to a single table
If you only grant CONNECT to a database, the user can connect but has no other privileges. You have to grant USAGE on namespaces (schemas) and SELECT on tables and views individually like so:
GRANT CONNECT ON DATABASE mydb TO xxx;
-- This assumes you're actually connected to mydb..
GRANT USAGE ON SCHEMA public TO xxx;
GRANT SELECT ON mytable TO xxx;
Multiple tables/views (PostgreSQL 9.0+)
In the latest versions of PostgreSQL, you can grant permissions on all tables/views/etc in the schema using a single command rather than having to type them one by one:
GRANT SELECT ON ALL TABLES IN SCHEMA public TO xxx;
This only affects tables that have already been created. More powerfully, you can automatically have default roles assigned to new objects in future:
ALTER DEFAULT PRIVILEGES IN SCHEMA public
GRANT SELECT ON TABLES TO xxx;
Note that by default this will only affect objects (tables) created by the user that issued this command: although it can also be set on any role that the issuing user is a member of. However, you don't pick up default privileges for all roles you're a member of when creating new objects... so there's still some faffing around. If you adopt the approach that a database has an owning role, and schema changes are performed as that owning role, then you should assign default privileges to that owning role. IMHO this is all a bit confusing and you may need to experiment to come up with a functional workflow.
Multiple tables/views (PostgreSQL versions before 9.0)
To avoid errors in lengthy, multi-table changes, it is recommended to use the following 'automatic' process to generate the required GRANT SELECT to each table/view:
SELECT 'GRANT SELECT ON ' || relname || ' TO xxx;'
FROM pg_class JOIN pg_namespace ON pg_namespace.oid = pg_class.relnamespace
WHERE nspname = 'public' AND relkind IN ('r', 'v', 'S');
This should output the relevant GRANT commands to GRANT SELECT on all tables, views, and sequences in public, for copy-n-paste love. Naturally, this will only be applied to tables that have already been created.
Reference taken from this blog:
Script to Create Read-Only user:
CREATE ROLE Read_Only_User WITH LOGIN PASSWORD 'Test1234'
NOSUPERUSER INHERIT NOCREATEDB NOCREATEROLE NOREPLICATION VALID UNTIL 'infinity';
\connect YourDatabaseName;
Assign permission to this read-only user:
GRANT CONNECT ON DATABASE YourDatabaseName TO Read_Only_User;
GRANT USAGE ON SCHEMA public TO Read_Only_User;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO Read_Only_User;
GRANT SELECT ON ALL SEQUENCES IN SCHEMA public TO Read_Only_User;
REVOKE CREATE ON SCHEMA public FROM PUBLIC;
Assign permissions to read all newly tables created in the future
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO Read_Only_User;
From PostgreSQL v14 on, you can do that simply by granting the predefined pg_read_all_data role:
GRANT pg_read_all_data TO xxx;
Do note that PostgreSQL 9.0 (today in beta testing) will have a simple way to do that:
test=> GRANT SELECT ON ALL TABLES IN SCHEMA public TO joeuser;
Here is the best way I've found to add read-only users (using PostgreSQL 9.0 or newer):
$ sudo -upostgres psql postgres
postgres=# CREATE ROLE readonly WITH LOGIN ENCRYPTED PASSWORD '<USE_A_NICE_STRONG_PASSWORD_PLEASE';
postgres=# GRANT SELECT ON ALL TABLES IN SCHEMA public TO readonly;
Then log in to all related machines (master + read-slave(s)/hot-standby(s), etc..) and run:
$ echo "hostssl <PUT_DBNAME_HERE> <PUT_READONLY_USERNAME_HERE> 0.0.0.0/0 md5" | sudo tee -a /etc/postgresql/9.2/main/pg_hba.conf
$ sudo service postgresql reload
By default new users will have permission to create tables. If you are planning to create a read-only user, this is probably not what you want.
To create a true read-only user with PostgreSQL 9.0+, run the following steps:
# This will prevent default users from creating tables
REVOKE CREATE ON SCHEMA public FROM public;
# If you want to grant a write user permission to create tables
# note that superusers will always be able to create tables anyway
GRANT CREATE ON SCHEMA public to writeuser;
# Now create the read-only user
CREATE ROLE readonlyuser WITH LOGIN ENCRYPTED PASSWORD 'strongpassword';
GRANT SELECT ON ALL TABLES IN SCHEMA public TO readonlyuser;
If your read-only user doesn't have permission to list tables (i.e. \d returns no results), it's probably because you don't have USAGE permissions for the schema. USAGE is a permission that allows users to actually use the permissions they have been assigned. What's the point of this? I'm not sure. To fix:
# You can either grant USAGE to everyone
GRANT USAGE ON SCHEMA public TO public;
# Or grant it just to your read only user
GRANT USAGE ON SCHEMA public TO readonlyuser;
I’ve created a convenient script for that; pg_grant_read_to_db.sh. This script grants read-only privileges to a specified role on all tables, views and sequences in a database schema and sets them as default.
I read trough all the possible solutions, which are all fine, if you remember to connect to the database before you grant the things ;) Thanks anyway to all other solutions!!!
user#server:~$ sudo su - postgres
create psql user:
postgres#server:~$ createuser --interactive
Enter name of role to add: readonly
Shall the new role be a superuser? (y/n) n
Shall the new role be allowed to create databases? (y/n) n
Shall the new role be allowed to create more new roles? (y/n) n
start psql cli and set a password for the created user:
postgres#server:~$ psql
psql (10.6 (Ubuntu 10.6-0ubuntu0.18.04.1), server 9.5.14)
Type "help" for help.
postgres=# alter user readonly with password 'readonly';
ALTER ROLE
connect to the target database:
postgres=# \c target_database
psql (10.6 (Ubuntu 10.6-0ubuntu0.18.04.1), server 9.5.14)
You are now connected to database "target_database" as user "postgres".
grant all the needed privileges:
target_database=# GRANT CONNECT ON DATABASE target_database TO readonly;
GRANT
target_database=# GRANT USAGE ON SCHEMA public TO readonly ;
GRANT
target_database=# GRANT SELECT ON ALL TABLES IN SCHEMA public TO readonly ;
GRANT
alter default privileges for targets db public shema:
target_database=# ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO readonly;
ALTER DEFAULT PRIVILEGES
If your database is in the public schema, it is easy (this assumes you have already created the readonlyuser)
db=> GRANT SELECT ON ALL TABLES IN SCHEMA public to readonlyuser;
GRANT
db=> GRANT CONNECT ON DATABASE mydatabase to readonlyuser;
GRANT
db=> GRANT SELECT ON ALL SEQUENCES IN SCHEMA public to readonlyuser;
GRANT
If your database is using customschema, execute the above but add one more command:
db=> ALTER USER readonlyuser SET search_path=customschema, public;
ALTER ROLE
The not straightforward way of doing it would be granting select on each table of the database:
postgres=# grant select on db_name.table_name to read_only_user;
You could automate that by generating your grant statements from the database metadata.
Taken from a link posted in response to despesz' link.
Postgres 9.x appears to have the capability to do what is requested. See the Grant On Database Objects paragraph of:
http://www.postgresql.org/docs/current/interactive/sql-grant.html
Where it says: "There is also an option to grant privileges on all objects of the same type within one or more schemas. This functionality is currently supported only for tables, sequences, and functions (but note that ALL TABLES is considered to include views and foreign tables)."
This page also discusses use of ROLEs and a PRIVILEGE called "ALL PRIVILEGES".
Also present is information about how GRANT functionalities compare to SQL standards.
CREATE USER username SUPERUSER password 'userpass';
ALTER USER username set default_transaction_read_only = on;