Slack OAuth2 strategy for Überauth.

1. Setup your application at Slack API.

2. Add :ueberauth_slack to your list of dependencies in mix.exs:

   def deps do
     [{:ueberauth_slack, "~> 0.4"}]
   end

3. Add the strategy to your applications:

   def application do
     [applications: [:ueberauth_slack]]
   end

4. Add Slack to your Überauth configuration:

   config :ueberauth, Ueberauth,
     providers: [
       slack: {Ueberauth.Strategy.Slack, []}
     ]

   You can optionally restrict authentication by providing your team ID. Find your Slack team ID here. Note that this is NOT your team's Slack domain name!

   config :ueberauth, Ueberauth,
     providers: [
       slack: {Ueberauth.Strategy.Slack, [team: "0ABCDEF"]}
     ]

5. Update your provider configuration:

   config :ueberauth, Ueberauth.Strategy.Slack.OAuth,
     client_id: System.get_env("SLACK_CLIENT_ID"),
     client_secret: System.get_env("SLACK_CLIENT_SECRET")

6. Include the Überauth plug in your controller:

   defmodule MyApp.AuthController do
     use MyApp.Web, :controller
     plug Ueberauth
     ...
   end

7. Create the request and callback routes if you haven't already:

   scope "/auth", MyApp do
     pipe_through :browser
   
     get "/:provider", AuthController, :request
     get "/:provider/callback", AuthController, :callback
   end

8. You controller needs to implement callbacks to deal with Ueberauth.Auth and Ueberauth.Failure responses.

For an example implementation see the Überauth Example application.

Depending on the configured url you can initial the request through:

/auth/slack

Or with options:

/auth/slack?scope=users:read

By default the requested scope is "users:read". Scope can be configured either explicitly as a scope query value on the request path or in your configuration:

config :ueberauth, Ueberauth,
  providers: [
    slack: {Ueberauth.Strategy.Slack, [default_scope: "users:read,users:write"]}
  ]

Please see LICENSE for licensing details.