@cerbos/orm-prisma

Cerbos + Prisma ORM Adapter

An adapater library that takes a Cerbos Query Plan (PlanResources API) response and converts it into a Prisma where class object. This is designed to work alongside a project using the Cerbos Javascript SDK.

The following conditions are supported: and, or, eq, ne, lt, gt, lte, gte and in.

Requirements

• Cerbos > v0.16
• @cerbos/http or @cerbos/grpc client

Usage

npm install @cerbos/orm-prisma

This package exports a single function:

queryPlanToPrisma({ queryPlan, fieldNameMapper }): PrismaCondition

The function reqiures the full query plan from Cerbos to be passed in an object along with a fieldNameMapper.

A basic implementation can be as simple as:

import { GRPC as Cerbos } from "@cerbos/grpc";
import { PrismaClient } from "@prisma/client";

const prisma = new PrismaClient();
const cerbos = new Cerbos("localhost:3592", { tls: false });

// Fetch the query plan from Cerbos passing in the principal
// resource type and action
const queryPlan = await cerbos.planResources({
  principal: {....},
  resource: { kind: "resourceKind" },
  action: "view"
})

// Generate the prisma filter from the query plan
const filters = queryPlanToPrisma({
  queryPlan,
  fieldNameMapper: {
    "request.resource.attr.aFieldName": "prismaModelFieldName"
  }
});

// Pass the filters in as where conditions
// If you have prexisting where conditions, you can pass them in an AND clause
const result = await prisma.myModel.findMany({
  where: {
    AND: filters
  },
});

console.log(result)

The fieldNameMapper is used to convert the field names in the query plan response to names of fields in the Prisma model - this can be done as a map or a function:

const filters = queryPlanToPrisma({
  queryPlan,
  fieldNameMapper: {
    "request.resource.attr.aFieldName": "prismaModelFieldName"
  }
});


//or

const filters = queryPlanToPrisma({
  queryPlan,
  fieldNameMapper: (fieldName: string): string => {
    if(fieldName.indexOf("request.resource.") > 0) {
      return fieldName.replace("request.resource.attr", "")
    }

    if(fieldName.indexOf("request.principal.") > 0) {
      return fieldName.replace("request.principal.attr", "")
    }
  }
});

Full Example

A full Prisma application making use of this adapater can be found at https://github.com/cerbos/express-prisma-cerbos