Sentinel

Note

Currently master (this readme) and the latest hex release have diverged due to poor planning on my part while working on the next version of Sentinel. It also currently interacts poorly with the new directory structure of Phoenix 1.3. I'm currently working on an update to remedy this, but cannot promise it will be released soon.

If you'd like to assist in developing the latest version of Sentinel please reach out to me.

Things I wish Guardian included out of the box, like Ueberauth integration, routing, invitation flow, confirmation emails, and, password reset emails. It's just a thin wrapper on Guardian but everybody shouldn't have to roll this themselves when they build stuff.

I do my best to follow semantic versioning with this repo.

Suggestions? See the Contributing/Want something new? section.

Want an example app? Checkout Sentinel Example.

Installation

Here's how to add it to your Phoenix project, and things you need to setup:

# mix.exs

# Requires Elixir ~> 1.3

defp deps do
  # ...
  {:sentinel, "~> 2.0"},
  {:guardian_db, "~> 0.8.0"}, # If you'd like to database back your tokens, and prevent replayability
  # ...
end

Configure Guardian

Example config:

# config/config.exs

config :guardian, Guardian,
  allowed_algos: ["HS512"], # optional
  verify_module: Guardian.JWT,  # optional
  issuer: "MyApp",
  ttl: { 30, :days },
  verify_issuer: true, # optional
  secret_key: "guardian_sekret",
  serializer: Sentinel.GuardianSerializer,
  hooks: GuardianDb # optional if using guardiandb

More info

Optionally Configure GuardianDb

config :guardian_db, GuardianDb,
  repo: MyApp.Repo

The install task which ships with Sentinel, which you will run later in this walkthrough, creates the migration for the GuardianDb tokens.

Configure Sentinel

# config/config.exs

config :sentinel,
  app_name: "Test App",
  user_model: Sentinel.User, # should be your generated model
  send_address: "[email protected]",
  crypto_provider: Comeonin.Bcrypt,
  repo: Sentinel.TestRepo,
  ecto_repos: [Sentinel.TestRepo],
  auth_handler: Sentinel.AuthHandler,
  layout_view: MyApp.Layout, # your layout
  layout: :app,
  views: %{
    email: Sentinel.EmailView, # your email view (optional)
    error: Sentinel.ErrorView, # your error view (optional)
    password: Sentinel.PasswordView, # your password view (optional)
    session: Sentinel.SessionView, # your session view (optional)
    shared: Sentinel.SharedView, # your shared view (optional)
    user: Sentinel.UserView # your user view (optional)
  },
  router: Sentinel.TestRouter, # your router
  endpoint: Sentinel.Endpoint, # your endpoint
  invitable: true,
  invitation_registration_url: "http://localhost:4000", # for api usage only
  confirmable: :optional,
  confirmable_redirect_url: "http://localhost:4000", # for api usage only
  password_reset_url: "http://localhost:4000", # for api usage only
  send_emails: true,
  user_model_validator: {MyApp.Accounts, :custom_changeset}, # your custom validator
  registrator_callback: {MyApp.Accounts, :setup} # your callback function (optional)

See config/test.exs for an example of configuring Sentinel

invitation_registration_url, confirmable_redirect_url, and password_reset_url are three configuration settings that must be set if using the API routing in order to have some place to be directed to after completing the relevant server action. In most cases I'd anticipate this being a page of a SPA, Mobile App, or other client interface.

Configure Ueberauth

# config/config.exs

config :ueberauth, Ueberauth,
  providers: [
    identity: {
      Ueberauth.Strategy.Identity,
      [
        param_nesting: "user",
        callback_methods: ["POST"]
      ]
    },
  ]

Currently Sentinel is designed in such a way that the Identity Strategy must set params_nesting as "user". This is something that I would like to modify in future versions.

You'd also want to add other Ueberauth provider configurations at this point, as described in the respective provider documentation.

Configure Bamboo Mailer

# config/config.exs

config :sentinel, Sentinel.Mailer,
  adapter: Bamboo.TestAdapter

More info

Run the install Mix task

Create the database using Ecto if it doesn't yet exist.

mix sentinel.install

This will create a user model if it doesn't already exist, add a migration for GuardianDb migration, and add a migration for Ueberauth provider credentials.

You will want to delete the GuardianDb migration if you're choosing not to use it.

Currently the install task outputs the following warning:

warning: the :datetime type in migrations is deprecated, please use
:utc_datetime or :naive_datetime instead

This is due to the fact that Phoenix's generators don't appear to support utc_datetime being passed in. Please modify the generated migration accordingly. Phoenix's generators also appear to not support setting null: false with the migration generator, so you will want to set that in the migration for the user email as well.

Mount the desired routes

defmodule MyApp.Router do
  use MyApp.Web, :router
  require Sentinel

  # ...
  # ...

  scope "/" do
    # pipe_through, browser, api, or your own pipeline depending on your needs
    # pipe_through :browser
    # pipe_through :api
    Sentinel.mount_ueberauth
  end

  scope "/" do
    pipe_through :browser
    Sentinel.mount_html
  end

  scope "/api", as: :api do
    pipe_through :api
    Sentinel.mount_api
  end
end

Be aware that the routes mounted by the macro Sentinel.mount_ueberauth must be mounted on the root of your URL, due to the way Ueberauth matches against routes. To illustrate, the route for requesting a given provider must be example.com/auth/:provider. If it is example.com/api/auth/:provider Ueberauth will not properly register requests.

NOTE: You will run into an issue here if you set the scope to scope "/", MyApp.Router do.

The generated routes are shown in /lib/sentinel.ex:

Sentinel.mount_ueberauth

Sentinel.mount_html

Sentinel.mount_api

Overriding the Defaults

Confirmable

By default users are not required to confirm their account to login. If you'd like to require confirmation set the confirmable configuration field to :required. If you don't want confirmation emails sent, set the field to :false. The default is :optional.

Invitable

By default, users are required to have a password upon creation. If you'd like to enable users to create accounts on behalf of other users without a password you can set the invitable configuration field to true. This will result in the user being sent an email with a link to GET users/:id/invited, which you can complete by posting to the same URL, with the following params:

{
  "confirmation_token": "confirmation_token_from_email_provided_as_url_param",
  "password_reset_token": "password_reset_token_from_email_provided_as_url_param",
  "password": "newly_defined_user_password"
}

Custom Routes

If you want to customize the routes, or use your own controller endpoints you can do that by overriding the individual routes listed.

Generate custom views

If you want to use custom views, you'll need copy over the views and templates to your application. Sentinel provides a mix task make this a one-liner:

mix sentinel.gen.views

This mix task accepts a single argument of the specific context. This value can be "email", "error", "password", "session", "shared", or "user". Once you copy over a context's view and templates, you must update the config to point to your application's local files:

config :sentinel, views: %{user: MyApp.Web.UserView}

The keys for this views config map correspond with the list of contexts above.

Auth Error Handler

If you'd like to write your own custom authorization or authentication handler change the auth_handler Sentinel configuration option to the module name of your handler.

It must define two functions, unauthorized/2, and unauthenticated/2, where the first parameter is the connection, and the second is information about the session.

Custom model validator

If you want to add custom changeset validations to the user model, you can do that by specifying a user model validator:

config :sentinel, user_model_validator: {MyApp.Accounts, :custom_changeset}

This function must accept 2 arguments consisting of a changeset and a map of params and must return a changeset. The params in the second argument will be the raw params from the original request (not the ueberauth callback params).

def custom_changeset(changeset, attrs \\ %{}) do
  changeset
  |> cast(attrs, [:my_attr])
  |> validate_required([:my_attr])
  |> validate_inclusion(:my_attr, ["foo", "bar"])
end

Contributing/Want something new?

Create an issue. Preferably with a PR. If you're super awesome include tests.

As you recall from the license, this is provided as is. I don't make any money on this, so I do support when I feel like it. That said, I want to do my best to contribute to the Elixir/Phoenix community, so I'll do what I can.

Having said that if you bother to put up a PR I'll take a look, and either merge it, or let you know what needs to change before I do. Having experienced sending in PRs and never hearing anything about them, I know it sucks.