I'm trying to implement some kind of permission framework in Node js, using sequelize as an ORM (with Postgres). After hours of research, the closest thing I can find to do this with existing npm modules is using acl with acl sequelize to support my stack.
The problem is that it looks like the acl module assigns a role, where that role would get a set of permissions to all instances of a specific resource. However, I need to do permissioning for instances based on existing relationships of that user.
As an example, consider a permissioning system for a simple forum. It gives these permissions for each role:
// allow guests to view posts
acl.allow("guest", "post", "view");
// allow registered users to view and create posts
acl.allow("registered users", "post", ["view", "create"]);
// allow administrators to perform any action on posts
acl.allow("administrator", "post", "*");
Suppose that I want to also add the ability for registered users to also edit their own posts, and the user has a relationship to all the posts they've created.
Is there any way for this module to do this, or any other module that can support this kind of behavior on the database / ORM level?
If not, and I have to implement a custom one, what would the best approach to creating something like this.
There is relatively new library CASL. I'm the author of this library. And it's possible to implement your usecase quite easily:
const { AbilityBuilder } = require('casl')
const ability = AbilityBuilder.define((can, cannot) => {
can('read', 'all')
can(['update', 'delete'], 'Article', { author_id: loggedInUser.id })
})
The code above basically says:
- anyone can read everything
- anyone can update and delete articles where author_id equals logged in user id
Later you can do:
ability.can('delete', 'Post')
//or
ability.can('update', post)
// where post variable is an instance of your Post model
Also there is an article which explains how to integrate CASL with MongoDB and Express exactly for your usecase.
Related
I want to access different models with same plurals. Is there any way in loopback to do so, e.g.:
get-account.json
{
"name": "getAccount",
"plural": "account"
}
to access get-account.js and inside it remoteMethod with http path /
get-smtp-account.json
{
"name": "getSmtpAccount",
"plural": "account"
}
to access get-smtp-account.js and inside it remoteMethod with http path /smtp
I think you are missing the point of Restful resources.
The restful specification is all about using the http verbs, representing CRUD actions like this:
GET: READ -
POST: CREATE -
PUT: UPDATE -
DELETE: DELETE
Each model should represent a resource, that would be the name of a single entry in the persistance, for example, account.
Because we are storing a collection of models, we use a "plural" to refer to this resources, thats why all endpoints should be named in plural, in this example that would be accounts.
So, in any restful resource, if you wanna read data from the persistance, you should use
GET http://0.0.0.0/api/accounts
In loopback, you can create relations between models. This relations, are representations of the relations in the persistance (db). So you can create a model called "smtp".
After the relation is made, you can query the account and "include" the smtp relation, bringing together all users with their data.
Check the documentation for more information https://docs.strongloop.com/display/public/LB/Creating+model+relations
If you have more questions, like, how to create relations between models, i'm really happy to help you in another question.
Background:
I have a set of models, including a User and various other models, some of which contain references to a User. I am exposing these models for querying via a GraphQL API generated by Graffiti, backed by a Mongo database using the graffiti-mongoose adaptor. My current REST API (which I am migrating to GraphQL) uses JSON Web Tokens to authenticate users, and has some custom permission logic on the server side to handle access control.
Problem:
I'd like to restrict access to objects in GraphQL based upon the current logged-in user. Some models should be accessible for reads by unauthenticated calls. Most other models should be only accessible to the User who created them. What's the best way to manage access control to objects via the Graffiti-generated API?
In general, are there good patterns of access control for GraphQL? And in particular, are there any good examples or libraries for doing it with Graffiti?
Notes:
I understand that pre- and post- hooks have been implemented for graffiti-mongoose, and that they can be used to do basic binary checks for authentication. I'd like to see how a more detailed access-control logic could be worked into a GraphQL API. In the future, we'll want to support things like Administrators who have access to model instances created by a certain group of Users (e.g. Users whose Affiliations include that of the Administrator).
Typically GraphQL does not handle access control directly, instead delegating that responsibility to whatever data system it interfaces with. In your case that sounds like Mongoose.
Since access control logic is often arbitrary logic (for example, has this user been banned from some content? did the publisher of that content restrict it with custom privacy settings? etc.), and it sounds like in your case this access control logic is in fact custom, it should live in the "resolve" function which produces a value for a GraphQL field.
For example:
var UserType = new GraphQLObjectType({
name: 'User',
fields: {
name: { type: GraphQLString },
birthday: {
type: GraphQLString,
resolve(user, context) {
var auth = context.myLoggedInAuth;
if (myCanAuthSeeBirthday(auth, user)) {
return user.birthday;
}
}
}
}
});
I create a rule base access control to be used with GraphQL.
https://github.com/joonhocho/graphql-rule
It is simple and unopionated that it can be used with or without GraphQL.
You can use it with a plain javascript objects.
Hope it helps GraphQLers!
I built a Social Network web app in Node. I added a group model for create a group of Users like facebook.
I've been looking everywhere for a npm modules that i could use and i have searched google and stackoverflow but i haven't found anything.
This is my the Group Model I add to my proyect.
var groupSchema = mongoose.Schema({
name: String,
motivation: String,
destination: String,
days: String,
members: [String],
profile: String
});
module.exports = mongoose.model('Group', groupSchema);
Does anyone has a good way to do this?
Note: I use a groupController and I thought to use 3 actions. One for show Users, One for add the User and One to create but it did not work.
Unfortunately, there aren't any really well rounded authorization frameworks for node yet (afaik).
I'm the author of the express-stormpath library which does some of this, but isn't a catch-all for authorization rules yet.
The way the express-stormpath library works is like so:
You have an Account object.
You have a Group object.
You can create Groups, and assign Accounts to those Groups. So you might have groups called:
admins
users
anonymousUsers
etc.
Then, on each Group, you can store permission data using this JSON blob thing. So you might do something like:
Group.customData.permissions = ['can_read', 'can_write', ...];
The library also provides some middleware tools for working with users / groups, for instance, you can say something like:
app.get('/secret', stormpath.groupsRequired(['admins']), function(req, res) {
// if you get here, you must be in the admins group
});
If you'd like to check it out, you can read more about it here: https://docs.stormpath.com/nodejs/express/
If a post has been made to /user, and my data model says that ever user must have a group, how, after successfully creating a user, would I trigger a new group to be created in sails.js? For that matter, how can I get into another controller from a lifecycle callback like afterCreate or via other means?
You cannot call a controller inside a model, that would violate MVC pattern. You can create the group via
Group.create(obj)
or put your creation logic inside a service.
It sounds like you might be confusing models and controllers, which is easy to do if you're new to Sails because of the blueprints functionality it provides. That is to say: you don't need GroupController to create a Group model instances, and GroupController.create is not the correct way to create a new Group programatically. GroupController.create is a method that's called automatically when you POST to /group because Sails has set up a "blueprint" create action at that location.
The correct way to create a Group programmatically is by using the create method of the Group model class, which is globally available in a Sails app. So in your afterCreate, you could have:
afterCreate: function(values, cb) {
Group.create({user: values.id}).exec(cb);
}
Note that the latest version of Sails (v0.10.0-rc5) supports nested creates, so if you've defined User and Group to be associated with each other, you could just POST something like this to /user:
{
name: "Joe Blow",
age: 25,
group: {
name: "Joe's group"
}
}
and the group will be created and associated with the user automatically. If you POST an embedded Group with a primary key, it will search for an existing group with that key and link it to the new User instead of creating a new Group.
I'm new to angular and developing my first 'real' application. I'm trying to build a calendar/scheduling app ( source code can all be seen on github ) and I want to be able to change the content if there is a user logged in (i.e. display details relevant to them) but here's the catch:
I don't want the app to be dependent on having a logged in user ( needs to be something that can be configured to work publicly, privately or both)
I don't want to implement the user/login within this app if it can be avoided ( I want to eventually include my app in another app where this might be implemented but isn't necessarily implemented using any particular security frameworks or limited to any)
I had an idea of creating some global variable user that could be referenced through out my application, or if I had to implement a system to do it all in this app that I could do so in in some abstract way so that different options could be injected in.
some of my ideas or understanding of what I should be doing may be completely wrong and ignorant of fundamentals but I genuinely do not know what approach I should take to do this.
In case it is relevant I currently don't have any back-end but eventually hope use MongoDB for storage and nodejs for services but I also want to try keep it open-ended to allow others to use different storage/backends such as sql and php
is there away to have a global uservariable/service that I could inject/populate from another (parent?) app?
If so what would be the best approach to do so?
If Not, why and what approach should I take and why?
Update
I Believe from comments online and some suggestion made to me that a service would be the best option BUT How would I go about injecting from a parent application into this applications service?
If your (single) page is rendered dynamically by the server and the server knows if you are logged-in or not, then you could do the following:
Dynamically render a script tag that produces:
<script>
window.user = { id: 1234, name: 'User A', isLoggedIn: true };
</script>
For non logged-in users:
<script>
window.user = { isLoggedIn: false };
</script>
For convinience, copy user to a value inside angular's IOC:
angular.module('myApp').value('user', window.user);
Then, you can use it in DI:
angular.module('myApp').factory('myService', function(user) {
return {
doSomething: function() {
if (user.isLoggedIn) {
...
} else {
...
}
}
};
});
Something tricky (which you should thing twice before doing [SEE COMMENTS]) is extending the $scope:
angular.module('myApp').config(function($provide) {
$provide.decorator('$controller', function($delegate, user) {
return function(constructor, locals) {
locals.$scope._user = user;
return $delegate(constructor, locals);
};
});
});
This piece of code decorates the $controller service (responsible for contructing controllers) and basically says that $scope objects prior to being passed to controllers, will be enhanced with the _user property.
Having it automatically $scoped means that you can directly use it any view, anywhere:
<div ng-if="_user.isLoggedIn">Content only for logged-in users</div>
This is something risky since you may end up running into naming conflicts with the original $scope API or properties that you add in your controllers.
It goes without saying that these stuff run solely in the client and they can be easily tampered. Your server-side code should always check the user and return the correct data subset or accept the right actions.
Yes you can do it in $rootScope. However, I believe it's better practice to put it inside a service. Services are singletons meaning they maintain the same state throughout the application and as such are prefect for storing things like a user object. Using a "user" service instead of $rootScope is just better organization in my opinion. Although technically you can achieve the same results, generally speaking you don't want to over-populate your $rootScope with functionality.
You can have a global user object inside the $rootScope and have it injected in all your controllers by simply putting it into the arguments of the controller, just as you do with $scope. Then you can implement functionalities in a simple check: if($rootScope.user). This allows you to model the user object in any way you want and where you want, acting as a global variable, inside of Angular's domain and good practices with DI.
Just to add on my comment and your edit. Here is what the code would look like if you wanted to be able to re-use your user service and insert it into other apps.
angular.module('user', []).service('userService', [function(){
//declare your user properties and methods
}])
angular.module('myApp', ['user'])
.controller('myCtrl', ['userService', '$scope', function(userService, scope){
// you can access userService from here
}])
Not sure if that's what you wanted but likewise you could have your "user" module have a dependency to another "parent" module and access that module's data the same way.