#Postgres create superuser code

Instead, the initial role that is created for you has most privileges needed to administer users and create databases and objects. If your PostgreSQL database is hosted with a service such as AWS RDS or Azure Postgres, you will probably not have access to a superuser role. That discussion is beyond the scope of this article but is generally not recommended without more experience. This initial superuser can be changed using the initdb command to instantiate your own PostgreSQL cluster. In PostgreSQL this initial superuser account is called postgres by default, which typically matches the system username that is running the PostgreSQL cluster process. Initially these tasks might be creating databases and additional roles, but there are a few tasks as of PostgreSQL 15 (installing some extensions, modifying some server parameters) that still require a superuser. To function properly, every PostgreSQL cluster needs to have at least one superuser to perform some administration tasks. This behavior is different than some other database systems. Being designated as a superuser bypasses all other checks, including things like Row Level Security (RLS). The only check that is performed is whether they are allowed to login and connect to the cluster.

#Postgres create superuser code

When a user has been granted superuser, no permission checks are performed when they execute SQL code (DDL/DML) or administer the cluster. In PostgreSQL, a superuser is a role that is allowed to do anything in the system and is analogous to the root user in Linux or the sa account in SQL Server. One last thing to discuss before diving into role creation and granting privileges is the concept of a superuser. We’ll look at this more in a follow-up article on object ownership and privileges. This behavior can be modified so that new objects a role creates automatically grants specific privileges to other roles, but out of the box, object ownership is a key concept to understand when creating roles and other objects in a PostgreSQL database. Instead, objects are always owned by a role (and only one role) which must set privileges for other roles in most cases. That’s not how it works in PostgreSQL without some intervention. SELECT) should be able to select from any table by default.

For example, most users would probably expect that two roles with the same database or schema privileges (eg. Any access beyond files or data that they own must be specifically granted to them.Īlthough not stated specifically in documentation, many of the nuances of PostgreSQL security and how roles and privileges work together, feel like they are implemented with PoLP in mind.įor instance, only the owner of a database object (schema, table, function, etc.) can use or alter it unless specific access has been granted to other roles. One other key idea to discuss is the Principle of Least Privilege (PoLP), an information security methodology that states users should only be granted access to the least amount of information needed to do their job or task. It does not mean that multiple servers are setup in a multi-node environment. This is the way that PostgreSQL refers to the individual server/instance that’s running and hosting (a cluster of) databases. If you are new to PostgreSQL, this term may really confuse you. Throughout this article you will see references to a PostgreSQL cluster.

This is typically done by granting group roles (those that cannot login) to user roles (those that can login) to assist with privilege management.ĭepending on your previous experience with information security (within a database, operating system, or application), the way that these components work together in PostgreSQL may be different than you would expect. Privileges assigned to one role can be granted to other roles.

Often these will be applied at a database or schema level, but the ability to apply specific access to individual objects is always available. Privileges: The types of access that can be granted to a role for a database object.Databases, schema, tables, views, procedures, functions, and more can each have different privileges applied to them for any role. Database Objects: Anything that can be created or accessed in the PostgreSQL cluster is referred to as an object.Please note, while the CREATE USER and CREATE GROUP commands still exist, they are simply aliases for CREATE ROLE. By convention, a ROLE that allows login is considered a user, while a role that is not allowed to login is a group. Roles: There is only one type of authentication principal in PostgreSQL, a ROLE, which exists at the cluster level.

This can be through password, trust, or some other federated login (like Kerberos)Īs an authenticated user, what am I permitted to do within the system?īefore we get started, lets establish a few terms: Verify that the user is who they claim to be.