postgres-adapter uses tokio-postgres and deadpool-postgres as an adapter for Casbin-rs. With this library, Casbin can load policy from Postgres or save policy to it with fully asynchronous support and prepared statements.

Add it to Cargo.toml

postgres-adapter = { version = "0.1.0" }
tokio = "1.19.2"

1. Set up database environment

   #!/bin/bash
   
   docker run -itd \
       --restart always \
       -e POSTGRES_USER=casbin_rs \
       -e POSTGRES_PASSWORD=casbin_rs \
       -e POSTGRES_DB=casbin \
       -p 5432:5432 \
       -v /srv/docker/postgresql:/var/lib/postgresql \
       postgres:11;

2. Create table casbin_rule

   # PostgreSQL
   psql postgres://casbin_rs:[email protected]:5432/casbin -c "CREATE TABLE IF NOT EXISTS casbin_rule (
       id SERIAL PRIMARY KEY,
       ptype VARCHAR NOT NULL,
       v0 VARCHAR NOT NULL,
       v1 VARCHAR NOT NULL,
       v2 VARCHAR NOT NULL,
       v3 VARCHAR NOT NULL,
       v4 VARCHAR NOT NULL,
       v5 VARCHAR NOT NULL,
       CONSTRAINT unique_key_sqlx_adapter UNIQUE(ptype, v0, v1, v2, v3, v4, v5)
       );"
   

3. Configure env

   Rename sample.env to .env and put DATABASE_URL, POOL_SIZE inside

   DATABASE_URL=postgres://casbin_rs:casbin_rs@localhost:5432/casbin
   POOL_SIZE=8

   Or you can export DATABASE_URL, POOL_SIZE

   export DATABASE_URL=postgres://casbin_rs:casbin_rs@localhost:5432/casbin
   export POOL_SIZE=8

use postgres_adapter::casbin::prelude::*;
use postgres_adapter::casbin::Result;
use postgres_adapter::TokioPostgresAdapter;
use tokio_postgres::NoTls;

#[tokio::main]
async fn main() -> Result<()> {
    let m = DefaultModel::from_file("examples/rbac_model.conf").await?;
    
    let a = TokioPostgresAdapter::new("postgres://casbin_rs:[email protected]:5432/casbin", 8, NoTls).await?;
    let mut e = Enforcer::new(m, a).await?;
    
    Ok(())
}

• postgres