How to revoke alter privilege from postgres? - sql

My Postgres DB has a user - "myuser" who has access to everycommand in schema my_schema.
I want to restrict the user to use only basic sequelize commands like Create, Update, Delete, Select. But the user should not be able to Alter the table (in sequelize, he shouldn't be able to do .sync{} operation).
I have already tried doing:
REVOKE ALTER ALL TABLES IN SCHEMA my_schema from myuser
But the above command is giving error!
Commands I have used to create role is:
CREATE ROLE app_readwrite1;
GRANT CONNECT ON DATABASE dvdrental TO app_readwrite1;
GRANT USAGE, CREATE ON SCHEMA app_schema TO app_readwrite1;
GRANT SELECT, INSERT, UPDATE, DELETE ON ALL TABLES IN SCHEMA app_schema TO app_readwrite1;
ALTER DEFAULT PRIVILEGES IN SCHEMA app_schema GRANT SELECT, INSERT, UPDATE, DELETE ON TABLES TO app_readwrite1;
GRANT USAGE ON ALL SEQUENCES IN SCHEMA app_schema TO app_readwrite1;
ALTER DEFAULT PRIVILEGES IN SCHEMA app_schema GRANT USAGE ON SEQUENCES TO app_readwrite1;
After creating role above, I am creating user and assigning him the role.
Still, I can use Model.sync()- basically "ALTER" command along with CRUD operations.
How can I restrict the user from using alter command?

Related

Create DML, DDL, DQL user in PostgreSQL

I need to create 3 users with different DML, DDL, DQL on newly created clean Database in PostgreSQL.
DML should have SELECT, UPDATE, DELETE
DDL should have CREATE, DROP, ALTER, TRUNCATE, INSERT
DQL should have SELECT
all of this in standard scheme public.
Important is that user inherit right on newly created tables by DDL user.
users ref: https://www.geeksforgeeks.org/sql-ddl-dql-dml-dcl-tcl-commands/
I did some coding but I'm pretty new in PostgreSQL and it didn't work :(
The main problem was that I cannot perform GRANT or REVOKE on CREATE, DROP, ALTER, TRUNCATE :(
Can someone help please?
Maybe you have something similar already prepared?
The setup you want, can be done to some extent. However these privileges are controlled on schema level, not on database level.
Assuming you have a schema app_schema for which this should be defined, you can do the following:
First create the users:
create user ddl with password '***';
create user dml with password '***';
create user dql with password '***';
Then create the schema:
create schema app_schema;
Then allow the ddl user to create objects:
grant create,usage on schema app_schema to ddl;
Then change the default privileges on the schema, so that every table (or view, or sequence ...) created by the ddl user is accessible by the dml and dql users:
alter default privileges
for role ddl
grant select,update,delete on tables
to dml;
alter default privileges
for role ddl
grant select on tables
to dql;
This will affect all future tables created in the schema by the user ddl.
The owner of the tables automatically has the privileges to INSERT,UPDATE,DELETE or TRUNCATE the tables.
I have never tried this, but it seems possible to revoke the UPDATE and SELECT privileges:
alter default privileges
for role ddl
in schema app_schema
revoke update,select,delete on tables
from ddl;
If there are already tables in the schema, you need to grant the desired privileges for them:
grant select,insert,update,delete on all tables
in schema app_schema
to dml;
grant select on all tables
in schema app_schema
to dql;

Grant from schema A of Schema B tables to schema C

I have an application schema U32_C5 and another schema MIG_SRC which has some tables and then we have a ROLE RO_ROLE on which we have some grants of tables from Schema U32_C5.
The RO_ROLE is assigned to another Schema MRGO_RO which is Read Only.
Here I need to grant select on tables from MIG_SRC to MRGO_RO catch here is that the process which and from where I can include these grants is run from application schema U32_C5 in production so when I tried to to something like below it says table or view does not exists (which seems to be obvious)
execute Grant from U32_C5
grant select on MIG_SRC.MOBILE_CELLPHONE_PAIRINGS to MRGO_RO;
Another way which I think of is creating DB link on MRGO_RO for MIG_SRC Schema but it enables read/write operation as well on MIG_SRC tables which is not allowed on production.
DB Links is present on U32_C5 Schema for MIG_SRC Schema
So looking for a way to accomplish above task without creating DB Link any suggestion is welcome.
Sample Script of requirement what I want to achieve Please Remember I cannot and do not want Login to MIG_SRC and only way I am looking for is to do it by using U32_C5 and without DBA HELP
A RO ROLE Created by DBA's
Create role RO_ROLE;
/* Create application schema, table inside it and grant select on it to RO_ROLE*/
CREATE USER U32_C5 IDENTIFIED BY U32_C5 DEFAULT TABLESPACE;
GRANT ALTER SESSION TO U32_C5;
GRANT CREATE SESSION TO U32_C5;
GRANT CREATE database link TO U32_C5;
GRANT CREATE table TO U32_C5;
create table U32_C5_test_tab (id number);
grant select on U32_c5.U32_C5_Test_tab to RO_ROLE;
/* Create Read Only schema, grant RO_ROLE to it */
CREATE USER mrgo_ro IDENTIFIED BY mrgo_ro DEFAULT TABLESPACE;
GRANT ALTER SESSION TO mrgo_ro;
GRANT CREATE SESSION TO mrgo_ro;
grant ro_role to mrgo_ro;
/* Create SRC schema, table inside it */
CREATE USER MIG_SRC IDENTIFIED BY MIG_SRC DEFAULT TABLESPACE;
GRANT ALTER SESSION TO MIG_SRC;
GRANT CREATE SESSION TO MIG_SRC;
GRANT CREATE database link TO MIG_SRC;
GRANT CREATE table TO MIG_SRC;
create table mig_src_test_tab (id number);
/* login to Apllication Schema U32_C5 */
sqlplus U32_C5/U32_C5#SID
grant select on mig_src.mig_src_test_tab to mrgo_ro; -- for me it gives error here at this step table or does not exist
/* login to Read Only Schema mrgo_ro */
sqlplus mrgo_ro/mrgo_ro#SID
select * from mig_src.mig_src_test_tab;
or
select * from mig_src_test_tab;
If I understood you correctly, then WITH GRANT OPTION is what you're missing.
Once someone (A) grants privileges on their own objects to someone else (B), and that (B) has to "forward" those privileges to (C), then it is the WITH GRANT OPTION that helps.
Documentation says:
Specify WITH GRANT OPTION to enable the grantee to grant the object privileges to other users and roles.
Restriction on Granting WITH GRANT OPTION You can specify WITH GRANT OPTION only when granting to a user or to PUBLIC, not when granting to a role.
It means that you should grant privileges directly, not via role. That fact doesn't have to be a drawback because of named PL/SQL procedures, where privileges acquired via roles won't work anyway, so you might end up in direct grants anyway.
Other option - which you might consider - is related to what you said:
when I tried to to something like below it says table or view does not exists
If you created a synonym for those tables, then you wouldn't get such an error.
Database link isn't an option, as you said - by using it, you have full access (as you have to know username/password to create the DB link, and that isn't really read only access).

Preventing users from altering default privileges on PostgreSQL

I'm testing database permissions on PostgreSQL and i'm trying to prevent a common user (readuser) from executing an 'ALTER DEFAULT PRIVILEGES' statement. However i cannot find a way to revoke this specific permission, and couldn't find anything about it on documentation.
I started a local PostgreSQL 11.2 instance, removed connect permisssions, created a database testdb and revoked table creation on the public schema.
revoke connect on database postgres from public;
create database testdb with template template0 --lc_collate "pt_BR.utf8" lc_ctype "pt_BR.utf8";
revoke connect on database testdb from public;
\c :database
revoke all on schema public from public;
grant all on schema public to postgres;
create schema private;
After that, I created a user with read permissions only:
create user readuser
with nosuperuser
nocreatedb
nocreaterole
noreplication
login
encrypted password 'testpassword';
grant connect
on database testdb
to readuser;
Then create a schema testschema and granted read permissions on it's tables:
grant usage
on schema testschema
to readuser;
grant select
on all tables
in schema testschema
to readuser;
Even though i only set read permissions on all schemas and tables, the 'readuser' user can still perform 'alter default privileges' query without a permission error:
alter default privileges in schema testschema grant select on tables to readuser;
ALTER DEFAULT PRIVILEGES
I would like some help on preventing a user from altering it's default privileges, so that it cannot mess up permissions for tables created in the future.
Try this by revoking the EXECUTE from the role postgres that granted the default privilege of execute to readuser
ALTER DEFAULT PRIVILEGES FOR ROLE postgres IN SCHEMA testschema REVOKE EXECUTE ON FUNCTIONS FROM readuser;

Grant privileges on future tables in PostgreSQL?

I am running PostgreSQL 9.3.1. I have test database and backup user which is used to backup the database. I have no problems with granting privileges to all current tables, but I have to grant privileges each time the new table is added to schema.
createdb test
psql test
test=# create table foo();
CREATE TABLE
test=# grant all on all tables in schema public to backup;
GRANT
test=# create table bar();
CREATE TABLE
psql -U backup test
test=> select * from foo;
test=> select * from bar;
ERROR: permission denied for relation bar
Is it possible to grant access to tables which will be created in future without making user owner of the table?
It looks like the solution is to alter default privileges for backup user:
alter default privileges in schema public grant all on tables to backup;
alter default privileges in schema public grant all on sequences to backup;
From the comment by Matt Schaffer:
As caveat, the default only applies to the user that executed the
alter statement. This confused me since I was driving most of my
permissions statements from the postgres user but creating tables from
an app user. In short, you might need something like this depending on
your setup:
ALTER DEFAULT PRIVILEGES FOR USER webapp IN SCHEMA public GRANT SELECT ON SEQUENCES TO backup;
ALTER DEFAULT PRIVILEGES FOR USER webapp IN SCHEMA public GRANT SELECT ON TABLES TO backup;
Where webapp is the user that will be creating new tables in the futrue and backup is the user that will be able to read from new tables created by webapp.
If you want the backup user to have access to the future tables of userN,
you must run the code below under each userN who creates new tables,
because ALTER DEFAULT PRIVILEGES...
works only for objects by that user under whom you run ALTER DEFAULT PRIVILEGES...
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT ALL ON TABLES TO backup;
I am trying to create a role, grant connect access to the role and then alter default privileges to keep access for future objects. However, it seems that the below command doesn't work at role level.
alter default privileges in schema public grant all on tables to backup;
I followed the below documentation but seems that there are two command do not work for roles.
DOC: https://aws.amazon.com/blogs/database/managing-postgresql-users-and-roles/
First command:
GRANT CONNECT ON DATABASE mydatabase TO readonly;
Second command:
GRANT USAGE ON SCHEMA myschema TO readonly;
(For ROLES usually it needs TO ROLE, I also tried TO ROLE but still doesn't work.

PostgreSQL: Give all permissions to a user on a PostgreSQL database

I would like to give a user all the permissions on a database without making it an admin.
The reason why I want to do that is that at the moment DEV and PROD are different DBs on the same cluster so I don't want a user to be able to change production objects but it must be able to change objects on DEV.
I tried:
grant ALL on database MY_DB to group MY_GROUP;
but it doesn't seem to give any permission.
Then I tried:
grant all privileges on schema MY_SCHEMA to group MY_GROUP;
and it seems to give me permission to create objects but not to query\delete objects on that schema that belong to other users
I could go on by giving USAGE permission to the user on MY_SCHEMA but then it would complain about not having permissions on the table ...
So I guess my question is: is there any easy way of giving all the permissions to a user on a DB?
I'm working on PostgreSQL 8.1.23.
All commands must be executed while connected to the right database cluster. Make sure of it.
Roles are objects of the database cluster. All databases of the same cluster share the set of defined roles. Privileges are granted / revoked per database / schema / table etc.
A role needs access to the database, obviously. That's granted to PUBLIC by default. Else:
GRANT CONNECT ON DATABASE my_db TO my_user;
Basic privileges for Postgres 14 or later
Postgres 14 adds the predefined, non-login roles pg_read_all_data / pg_write_all_data.
They have SELECT / INSERT, UPDATE, DELETE privileges for all tables, views, and sequences. Plus USAGE on schemas. We can GRANT membership in these roles:
GRANT pg_read_all_data TO my_user;
GRANT pg_write_all_data TO my_user;
This covers all basic DML commands (but not DDL, and not some special commands like TRUNCATE or the EXECUTE privilege for functions!). The manual:
pg_read_all_data
Read all data (tables, views, sequences), as if having SELECT rights
on those objects, and USAGE rights on all schemas, even without
having it explicitly. This role does not have the role attribute
BYPASSRLS set. If RLS is being used, an administrator may wish to
set BYPASSRLS on roles which this role is GRANTed to.
pg_write_all_data
Write all data (tables, views, sequences), as if having INSERT,
UPDATE, and DELETE rights on those objects, and USAGE rights on
all schemas, even without having it explicitly. This role does not
have the role attribute BYPASSRLS set. If RLS is being used, an
administrator may wish to set BYPASSRLS on roles which this role is
GRANTed to.
All privileges without using predefined roles (any Postgres version)
Commands must be executed while connected to the right database. Make sure of it.
The role needs (at least) the USAGE privilege on the schema. Again, if that's granted to PUBLIC, you are covered. Else:
GRANT USAGE ON SCHEMA public TO my_user;
Or grant USAGE on all custom schemas:
DO
$$
BEGIN
-- RAISE NOTICE '%', ( -- use instead of EXECUTE to see generated commands
EXECUTE (
SELECT string_agg(format('GRANT USAGE ON SCHEMA %I TO my_user', nspname), '; ')
FROM pg_namespace
WHERE nspname <> 'information_schema' -- exclude information schema and ...
AND nspname NOT LIKE 'pg\_%' -- ... system schemas
);
END
$$;
Then, all permissions for all tables (requires Postgres 9.0 or later).
And don't forget sequences (if any):
GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA public TO my_user;
GRANT ALL PRIVILEGES ON ALL SEQUENCES IN SCHEMA public TO my_user;
Alternatively, you could use the "Grant Wizard" of pgAdmin 4 to work with a GUI.
This covers privileges for existing objects. To also cover future objects, set DEFAULT PRIVILEGES. See:
Grant privileges for a particular database in PostgreSQL
How to manage DEFAULT PRIVILEGES for USERs on a DATABASE vs SCHEMA?
There are some other objects, the manual for GRANT has the complete list. As of Postgres 14:
privileges on a database object (table, column, view, foreign table, sequence, database, foreign-data wrapper, foreign server, function, procedure, procedural language, schema, or tablespace)
But the rest is rarely needed. More details:
Grant privileges for a particular database in PostgreSQL
How to grant all privileges on views to arbitrary user
Consider upgrading to a current version.
GRANT ALL PRIVILEGES ON DATABASE "my_db" to my_user;
In PostgreSQL 9.0+ you would do the following:
GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA MY_SCHEMA TO MY_GROUP;
GRANT ALL PRIVILEGES ON ALL SEQUENCES IN SCHEMA MY_SCHEMA TO MY_GROUP;
If you want to enable this for newly created relations too, then set the default permissions:
ALTER DEFAULT PRIVILEGES IN SCHEMA MY_SCHEMA
GRANT ALL PRIVILEGES ON TABLES TO MY_GROUP;
ALTER DEFAULT PRIVILEGES IN SCHEMA MY_SCHEMA
GRANT ALL PRIVILEGES ON SEQUENCES TO MY_GROUP;
However, seeing that you use 8.1 you have to code it yourself:
CREATE FUNCTION grant_all_in_schema (schname name, grant_to name) RETURNS integer AS $$
DECLARE
rel RECORD;
BEGIN
FOR rel IN
SELECT c.relname
FROM pg_class c
JOIN pg_namespace s ON c.namespace = s.oid
WHERE s.nspname = schname
LOOP
EXECUTE 'GRANT ALL PRIVILEGES ON ' || quote_ident(schname) || '.' || rel.relname || ' TO ' || quote_ident(grant_to);
END LOOP;
RETURN 1;
END; $$ LANGUAGE plpgsql STRICT;
REVOKE ALL ON FUNCTION grant_all_in_schema(name, name) FROM PUBLIC;
This will set the privileges on all relations: tables, views, indexes, sequences, etc. If you want to restrict that, filter on pg_class.relkind. See the pg_class docs for details.
You should run this function as superuser and as regular as your application requires. An option would be to package this in a cron job that executes every day or every hour.
I did the following to add a role 'eSumit' on PostgreSQL 9.4.15 database and provide all permission to this role :
CREATE ROLE eSumit;
GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA public TO eSumit;
GRANT ALL PRIVILEGES ON DATABASE "postgres" to eSumit;
ALTER USER eSumit WITH SUPERUSER;
Also checked the pg_table enteries via :
select * from pg_roles;
Database queries snapshot :
In PostgreSQL 12 and later, it is possible to grant all privileges of a table in a database to a role/user/account.
The syntax is:
GRANT ALL ON table_name TO role_name;
If you want to grant it to all tables in the database then the syntax will be:
GRANT ALL ON ALL TABLES TO role_name;
If you want to grant it to all tables of a schema in the database then the syntax will be:
GRANT ALL ON ALL TABLES IN SCHEMA schema_name TO role_name;
Note: Remember you will need to select the database before you can grant its privileges to a user.
Resources: PostgreSQL GRANT
That's all
I hope this helps
GRANT USAGE ON SCHEMA schema_name TO user;
GRANT ALL ON SCHEMA schema_name TO user_name;
Give all permissions to a user on a PostgreSQL database:
Command:
grant all privileges on database [database_name] to [database_user_name];
Example:
grant all privileges on database studentdb to shaifullah;
OR
GRANT ALL PRIVILEGES ON DATABASE studentdb TO shaifullah;