PostgreSQL Casbin Adapter

PostgreSQL native adapter for Node-Casbin. With this library, Node-Casbin can load policy from PosgreSQL database or save policy to it. It supports loading filtered policies and is built for improving performances in PostgreSQL. It uses node-postgres to connect to PostgreSQL.

casbin-pg-adapter also adds advanced filtering capability. You can filter using LIKE or regexp expressions when using loadFilteredPolicy.

Installation

npm install casbin-pg-adapter

Simple example

import { newEnforcer } from "casbin";
import PostgresAdapter from "casbin-pg-adapter";

async function myFunction() {
    // Initialize a Postgres adapter and use it in a Node-Casbin enforcer:
    // The adapter can not automatically create database.
    // But the adapter will automatically and use the table named "casbin".
    // I think ORM should not automatically create databases.  
    const a = await PostgresAdapter.newAdapter({
        connectionString: "postgresql://casbin:casbin@localhost:5432/casbin"
    });

    const e = await newEnforcer("examples/rbac_model.conf", a);

    // Load the policy from DB.
    await e.loadPolicy();

    // Check the permission.
    e.enforce("alice", "data1", "read");

    // Modify the policy.
    // await e.addPolicy(...);
    // await e.removePolicy(...);

    // Save the policy back to DB.
    await e.savePolicy();
}

Filtering example

import { newEnforcer } from "casbin";
import PostgresAdapter from "casbin-pg-adapter";

async function myFunction() {
    const a = await PostgresAdapter.newAdapter({
        connectionString: "postgresql://casbin:casbin@localhost:5432/casbin"
    });

    const e = await newEnforcer("examples/rbac_model.conf", a);

    // Load the filtered policy from DB.
    await e.loadFilteredPolicy({
        p: ["alice"],
        g: ["", "role:admin"]
    });

    // Check the permission.
    e.enforce("alice", "data1", "read");
}

Advanced filtering example

import { newEnforcer } from "casbin";
import PostgresAdapter from "casbin-pg-adapter";

async function myFunction() {
    const a = await PostgresAdapter.newAdapter({
        connectionString: "postgresql://casbin:casbin@localhost:5432/casbin"
    });

    const e = await newEnforcer("examples/rbac_model.conf", a);

    // Load the filtered policy from DB.
    await e.loadFilteredPolicy({
        p: ["regex:(role:.*)|(alice)"],
        g: ["", "like:role:%"]
    });

    // Check the permission.
    e.enforce("alice", "data1", "read");
}

Configuration

You can pass any node-postgres options to the Adapter. See node-postgres documentation: Connecting to PostgreSQL.

Additional configurations

Avoid database migration

Additionnally, you can pass the following option to the Adapter:

• migrate (Boolean): If set to false, the Adapter will not apply migration when starting.

Note: If you use this parameter, you should apply migration manually:

async function startup(): Promise<void> {
    PostgresAdapter.migrate({
        connectionString: "postgresql://casbin:casbin@localhost:5432/casbin"
    });
}

async function createEnforcer(): Promise<Enforcer> {
    const a = await PostgresAdapter.newAdapter({
        connectionString: "postgresql://casbin:casbin@localhost:5432/casbin",
        migrate: false
    });

    return newEnforcer("examples/rbac_model.conf", a);
}

Disabling filtered behavior

If you want to use the savePolicy feature from node-casbin, you have to disable the filtered behavior of PostgresAdapter. You can do it by calling enableFiltered on the adapter:

a.enableFiltered(false);

Getting Help

• Node-Casbin
• Casbin-PG-Adapter

License

This project is under MIT License. See the LICENSE file for the full license text.