PowAssent: Instant multi-provider support for Pow

Multi-provider support for Pow with out-of-the-box support for many providers. I finally got a 0.1.0 release up today, and I hope some of you will find it useful

Please let me know if there’s anything that can be improved in the docs or with features. Thanks!

https://github.com/danschultzer/pow_assent
https://hexdocs.pm/pow_assent/

Pow thread: Pow - Robust, modular, extendable user authentication and management system

PowAssent details

Base strategies

• OAuth 1.0
• OAuth 2.0

Strategies

• Azure AD
• Basecamp
• Discord
• Facebook
• Github
• Google
• Instagram
• Slack
• Twitter
• VK

Few dependencies

PowAssent has nearly no dependencies. :httpc is used as the default HTTP client with built-in SSL validation!

Mint can be added for HTTP/2 support.

Can PowAssent be used without Pow?

Yes! You can use any strategy directly:

config = [
  client_id: "REPLACE_WITH_CLIENT_ID",
  client_secret: "REPLACE_WITH_CLIENT_SECRET",
]

{:ok, %{conn: conn, url: url}} = PowAssent.Strategy.Github.authorize_url(config, conn)

case PowAssent.Strategy.Github.callback(config, conn, params) do
  {:ok, %{conn: conn, user: user}} -> # …
  {:error, reason} -> # …
end

I’ve been using this technique for a lean super admin login.

What about Ueberauth?

You can use Ueberauth with Pow, or add a custom strategy that uses Ueberauth underneath!

However, most strategies uses the OAuth protocols, and it’s much easier to just add your custom strategy. It takes no time to set up. Pull requests are welcome!

A big difference from Ueberauth is that PowAssent is self contained. Strategies are built-in and consists of very little code. They rely on base strategies like OAuth or OAuth2 to do the heavy lifting. All strategies are consistent, and e.g. switching out underlying HTTP client or JSON library is no problem. Unfortunately with Ueberauth you’ll have several different dependencies that each handle things differently. This may also cause dependency conflicts.

Adding a custom strategy

Provider support is super easy. You just need to write one (tiny) module:

defmodule MyApp.CustomStrategy do
  use PowAssent.Strategy.OAuth2

  def default_config(_config) do
    [
      site: "https://api.example.com",
      user_url: "/authorization.json"
    ]
  end

  def normalize(_config, user) do
    %{
      "uid"   => user["id"],
      "name"  => user["name"],
      "email" => user["email"]
    }
  end
end

And then add it to your providers:

config :my_app, :pow_assent,
  providers: [
    custom_strategy: [
      client_id: "REPLACE_WITH_CLIENT_ID",
      client_secret: "REPLACE_WITH_CLIENT_SECRET",
      strategy: MyApp.CustomStrategy
    ]
  ]

Happy coding