Nestjs Basic ACL SDK

Table of Contents

• Nestjs Basic ACL SDK
• Table of Contents
• Description
• Motivation
• Requirements
• Usage
  • Install
  • Module Initialization
  • Decorators
  • Guard
  • Users synchronization

Description

This nestjs module offers a simple way to use some functionalities from the basic-acl-api.

Motivation

Making a direct fully working integration with basic-acl-api could be easy, but, this is an intent to make that process even easier and standar.

Requirements

1. Have a firebase project.
2. The service account json from firebase. more info
3. The firebase json config. more info
4. A created account in the Basic ACL Project

Usage

Install

npm i nestjs-basic-acl-sdk -S

OR

yarn add nestjs-basic-acl-sdk

Module Initialization

Import and add BasicAclModule it to the imports array of module for which you would like to discover handlers. It may make sense for your application to do this in a shared module or to re-export it so it can be used across modules more easily. You can check this docs in order to get more information about modules.

import { Module } from '@nestjs/common';
import { ConfigModule, ConfigService } from '@nestjs/config';
import { APP_GUARD } from '@nestjs/core';
import { BasicAclModule } from 'nestjs-basic-acl-sdk';

import appConfig from '../config/app.config';

import { AuthorizationGuard } from './guards/authorization.guard';

@Module({
  imports: [
    ConfigModule.forFeature(appConfig),
    BasicAclModule.registerAsync({
      imports: [ConfigModule],
      inject: [ConfigService],
      useFactory: (configService: ConfigService) => {
        return {
          companyUid: configService.get<string>('config.acl.companyUid'),
          accessKey: configService.get<string>('config.acl.accessKey'),
        };
      }
    })
   ],
  providers: [
    {
      provide: APP_GUARD,
      useClass: AuthorizationGuard,
    },
  ],
})
export class CommonModule { }

In the axample we're using the registerAsync method but you can also use the register method.

Decorators

One important part it's the ability to indicate the name of the resource (to accomplish a resource check) or if the resource is public (to pass by without resource checking).

import { Args, Mutation, Resolver, Query } from '@nestjs/graphql';
import { UsePipes, ValidationPipe } from '@nestjs/common';
import { PermissionName, Public } from 'nestjs-basic-acl-sdk';

import { User } from './user.entity';

import { UsersService } from './users.service';

import { CreateUserInput } from './dto/create-user-input';
import { GetUserByAuthUidInput } from './dto/get-uset-by-auth-uid-input.dto';
import { ResetUserPasswordInput } from './dto/reset-user-password-input.dto';
import { UpdateUserInput } from './dto/update-user-input.dto';
import { ChangeUserEmailInput } from './dto/change-user-email-input.dto';
import { ChangeUserPasswordInput } from './dto/change-user-password-input.dto';
import { ChangeUserPhoneInput } from './dto/change-user-phone-input.dto';
import { CreateUserFromAuthUidInput } from './dto/create.user-from-auth-uid.input.dto';

@UsePipes(new ValidationPipe({ whitelist: true, forbidNonWhitelisted: true }))
@Resolver(() => User)
export class UsersResolver {
  constructor(private readonly service: UsersService) {}

  @Public()
  @Mutation(() => User, { name: 'createUser' })
  createUser(
    @Args('createUserInput') createUserInput: CreateUserInput,
  ): Promise<User> {
    return this.service.create(createUserInput);
  }

  @Public()
  @Mutation(() => User, { name: 'createUserFromAuthUid' })
  createUserFromAuthUid(
    @Args('createUserFromAuthUidInput') createUserFromAuthUidInput: CreateUserFromAuthUidInput
  ): Promise<User> {
    return this.service.createFromAuthUid(createUserFromAuthUidInput);
  }

  @PermissionName('users:handle')
  @Mutation(() => User, { name: 'updateUser' })
  updateUser(
    @Args('updateUserInput') updateUserInput: UpdateUserInput,
  ): Promise<User> {
    return this.service.update(updateUserInput);
  }

  @PermissionName('users:handle')
  @Mutation(() => User, { name: 'changeUserEmail' })
  changeUserEmail(
    @Args('changeUserEmailInput') changeUserEmailInput: ChangeUserEmailInput,
  ): Promise<User> {
    return this.service.changeEmail(changeUserEmailInput);
  }

  @PermissionName('users:handle')
  @Mutation(() => User, { name: 'changeUserPassword' })
  changeUserPassword(
    @Args('changeUserPasswordInput')
    changeUserPasswordInput: ChangeUserPasswordInput,
  ): Promise<User> {
    return this.service.changePassword(changeUserPasswordInput);
  }

  @PermissionName('users:handle')
  @Mutation(() => User, { name: 'changeUserPhone' })
  changeUserPhone(
    @Args('changeUserPhoneInput') changeUserPhoneInput: ChangeUserPhoneInput,
  ): Promise<User> {
    return this.service.changePhone(changeUserPhoneInput);
  }

  @PermissionName('users:read')
  @Query(() => User, { name: 'getUserByAuthUid' })
  getUserByAuthUid(
    @Args('getUserByAuthUidInput') getUserByAuthUidInput: GetUserByAuthUidInput,
  ): Promise<User> {
    return this.service.getByAuthuid(getUserByAuthUidInput);
  }

  @Public()
  @Mutation(() => String, { name: 'resetUserPassword' })
  resetUserPassword(
    @Args('resetUserPasswordInput')
    resetUserPasswordInput: ResetUserPasswordInput,
  ): Promise<string> {
    return this.service.resetPassword(resetUserPasswordInput);
  }
}

as you can see we're using PermissionName decorator to indicate the name of the resource and the Public decorator to indicate that resource it's public

Guard

The other important aspect it's the custom implementation of a guard, in favor of the permission check.

You can check this docs in order to get more information about guards.

import {
  CanActivate,
  ExecutionContext,
  Injectable,
  Inject,
  Logger,
  UnauthorizedException,
  InternalServerErrorException,
} from '@nestjs/common';
import { Reflector } from '@nestjs/core';
import { ConfigType } from '@nestjs/config';
import { GqlExecutionContext } from '@nestjs/graphql';
import { BasicAclService } from 'nestjs-basic-acl-sdk';

import appConfig from '../../config/app.config';

import { IS_PUBLIC_KEY } from 'nestjs-basic-acl-sdk';
import { PERMISSION_NAME_KEY } from 'nestjs-basic-acl-sdk';

@Injectable()
export class AuthorizationGuard implements CanActivate {
  constructor(
    private readonly reflector: Reflector,
    @Inject(appConfig.KEY)
    private readonly appConfiguration: ConfigType<typeof appConfig>,
    private readonly basicAclService: BasicAclService
  ) {}

  async canActivate(context: ExecutionContext): Promise<boolean> {
    const isPublic = this.reflector.get<string>(IS_PUBLIC_KEY, context.getHandler());

    if (isPublic) return true;

    const ctx = GqlExecutionContext.create(context);
    const { req: request } = ctx.getContext();

    const authorizationHeader: string = request.headers['Authorization'] || request.headers['authorization'];
    if (!authorizationHeader) {
      throw new UnauthorizedException('authorization header not found.');
    }

    const tokenArray = authorizationHeader.split(' ');
    if (tokenArray.length !== 2) {
      throw new UnauthorizedException('invalid token format.');
    }

    const token = tokenArray[1];

    if (!token) {
      throw new UnauthorizedException('token not found.');
    }

    const permissionName = this.reflector.get<string>(PERMISSION_NAME_KEY, context.getHandler());

    if (!permissionName) {
      throw new InternalServerErrorException('acl slug not found.');
    }

    try {
      await this.basicAclService.checkPermission({
        token,
        permissionName,
      });

      return true;
    } catch (error) {
      Logger.error(`permission check error ${error.message}.`, AuthorizationGuard.name);
      throw new UnauthorizedException(error.message);
    }
  }
}

so in that guard implementation we're getting the information from the decorators and also we're trying to get the token to make the permission check, using the BasicAclService (it's also included in the sdk).

Users synchronization

You probably noticed, the basic ACL is a system that needs to be well synchronized with the users in your own system to accomplish the permission verifications and some other things, that why BasicAclService includes functions to create and get, update a user.

Creating a user

public async create(createUserInput: CreateUserInput): Promise<User> {
    const { phone, email, fullName, password } = createUserInput;

    const existingByPhone = await this.getByOneField({
      field: 'phone',
      value: phone,
      checkExisting: false,
    });

    if (existingByPhone) {
      throw new PreconditionFailedException(`already exist an user with the phone ${phone}.`);
    }

    const existingByEmail = await this.getByOneField({
      field: 'email',
      value: email,
      checkExisting: false,
    });

    if (existingByEmail) {
      throw new PreconditionFailedException(`already exist an user with the email ${email}.`);
    }

    const aclUser = await this.basicAclService.createUser({
      email,
      password,
      phone: `+57${phone}`,
      roleCode: '02U', // TODO: use a parameter
      sendEmail: true,
      emailTemplateParams: {
        fullName,
      }
    });

    try {
      const { authUid } = aclUser;

      const created = this.repository.create({
        email,
        fullName,
        phone,
        authUid,
      });

      const saved = await this.repository.save(created);

      return saved;
    } catch (error) {
      await this.basicAclService.deleteUser({
        authUid: aclUser.authUid,
      });

      throw error;
    }
  }

Maybe it's possible the user was previously created at the front, using other provider like google, github and so on... that's why you can use the createUser in this way:

public async createFromAuthUid(
  createUserFromAuthUidInput: CreateUserFromAuthUidInput
): Promise<User> {
  const { authUid, email, fullName = 'No assigned', phone } = createUserFromAuthUidInput;

  const existing = await this.getByOneField({
    field: 'authUid',
    value: authUid,
    checkExisting: false
  });

  if (existing) {
    throw new PreconditionFailedException(`the user with authUid ${authUid} already exist.`);
  }

  const aclUser = await this.basicAclService.createUser({
    authUid,
    roleCode: '02U',// TODO: use a parameter
    sendEmail: true,
    emailTemplateParams: {
      fullName,
    }
  });

  try {
    const { authUid } = aclUser;

    const created = this.repository.create({
      email,
      fullName,
      phone,
      authUid,
    });

    const saved = await this.repository.save(created);

    return saved;
  } catch (error) {
    await this.basicAclService.deleteUser({
      authUid: aclUser.authUid,
    });

    throw error;
  }
}

In these examples we're also using the deleteUser function when something goes wrong, but, it is up to you the way you implement the logic.

Contribute

Please feel free to contribute, just open a issue or pr I'll be happy to review it.