Slack Ruby Bot Server

Build a complete Slack bot service with Slack button integration, in Ruby.

Table of Contents

• What is this?
• Stable Release
• Make Your Own
• Usage
  • Storage
  • MongoDB
  • ActiveRecord
  • OAuth Version and Scopes
  • Slack App
  • API
  • App
  • Service Manager
    • Lifecycle Callbacks
    • Service Timers
    • Extensions
  • Service Class
  • HTML Templates
  • Access Tokens
• Sample Bots Using Slack Ruby Bot Server
  • Slack Bots with Granular Permissions
  • Legacy Slack Bots
• Copyright & License

What is this?

A library that contains a web server and a RESTful Grape API serving a Slack bot to multiple teams. Use in conjunction with slack-ruby-bot-server-events to build a complete Slack bot service, or slack-ruby-bot-server-rtm to build a (legacy) Classic RealTime Slack bot. Your customers can use a Slack button to install the bot.

Stable Release

You're reading the documentation for the next release of slack-ruby-bot-server. Please see the documentation for the last stable release, v1.2.0 unless you're integrating with HEAD. See UPGRADING when upgrading from an older version. See MIGRATING for help with migrating Legacy Slack Apps to Granular Scopes.

Make Your Own

This library alone will only register a new bot, but will not include any bot functionality. To make something useful, we recommend you get started from either slack-ruby-bot-server-events-app-mentions-sample (handles a single kind of event), or slack-ruby-bot-server-events-sample (handles all kinds of events) to bootstrap your project.

Usage

Storage

A database is required to store teams.

MongoDB

Use MongoDB with Mongoid as ODM. Configure the database connection in

mongoid.yml

mongoid

gem 'mongoid'
gem 'kaminari-mongoid'
gem 'mongoid-scroll'
gem 'slack-ruby-bot-server'

ActiveRecord

Use ActiveRecord with, for example, PostgreSQL via pg. Add the

activerecord

pg

otr-activerecord

cursor_pagination

gem 'pg'
gem 'activerecord', require: 'active_record'
gem 'slack-ruby-bot-server'
gem 'otr-activerecord'
gem 'cursor_pagination'

Configure the database connection in

config/postgresql.yml

default: &default
  adapter: postgresql
  pool: 10
  timeout: 5000
  encoding: unicode

development:
  <<: database: bot_development test: bot_test production: bot>
Establish a connection in your startup code.
ActiveRecord::Base.establish_connection(
  YAML.safe_load(
    ERB.new(
      File.read('config/postgresql.yml')
    ).result, [], [], true
  )[ENV['RACK_ENV']]
)

OAuth Version and Scopes

Configure your app's OAuth version and scopes as needed by your application.
SlackRubyBotServer.configure do |config|
  config.oauth_version = :v2
  config.oauth_scope = ['channels:read', 'chat:write']
end

The "Add to Slack" button uses the standard OAuth code grant flow as described in the Slack docs. Once clicked, the user is taken through the authorization process at Slack's site. Upon successful completion, a callback containing a temporary code is sent to the redirect URL you specified. The endpoint at that URL contains code that persists the bot token each time a Slack client is instantiated for the specific team.

Slack App

Create a new Slack App here.



Follow Slack's instructions, note the app client ID and secret, give the bot a default name, etc.

Within your application, edit your 
.env
 file and add 
SLACK_CLIENT_ID=...
 and 
SLACK_CLIENT_SECRET=...
 in it.

Run 
bundle install
 and 
foreman start
 to boot the app.
$ foreman start
07:44:47 web.1  | started with pid 59258
07:44:50 web.1  | * Listening on tcp://0.0.0.0:5000

Set the redirect URL in "OAuth & Permissions" be the location of your app. Since you cannot receive notifications on localhost from Slack use a public tunneling service such as ngrok to expose local port 9292 for testing.
$ ngrok http 5000
Forwarding https://ddfd97f80615.ngrok.io -> http://localhost:5000

Navigate to either localhost:9292 or the ngrok URL above. You should see an "Add to Slack" button. Use it to install the app into your own Slack team.

API

This library implements an app, SlackRubyBotServer::App and a service manager, SlackRubyBotServer::Service. It also provides default HTML templates and JS scripts for Slack integration.

App

The app instance checks for a working database connection, ensures indexes, performs migrations, sets up bot aliases and log levels. You can introduce custom behavior into the app lifecycle by subclassing 
SlackRubyBotServer::App
 and creating an instance of the child class in 
config.ru
.
class MyApp < SlackRubyBotServer::App
  def prepare!
    super
    deactivate_sleepy_teams!
  end

  private
  def deactivate_sleepy_teams!
    Team.active.each do |team|
      next unless team.sleepy?
      team.deactivate!
    end
  end
end

MyApp.instance.prepare!

Service Manager

Lifecycle Callbacks

You can introduce custom behavior into the service lifecycle via callbacks. This can be useful when new team has been registered via the API or a team has been deactivated from Slack.
instance = SlackRubyBotServer::Service.instance

instance.on :started, :stopped do |team|
team has been started or stopped
end
instance.on :created do |team, error, options|
a new team has been registered
end
instance.on :deactivated do |team, error, options|
an existing team has been deactivated in Slack
end
instance.on :error do |team, error, options|
an error has occurred
end

The following callbacks are supported. All callbacks receive a 
team
, except 
error
, which receives a 
StandardError
 object.

| callback       |  description                                                     |
|:--------------:|:-----------------------------------------------------------------|
| error          | an error has occurred                                            |
| creating       | a new team is being registered                                   |
| created        | a new team has been registered                                   |
| booting        | the service is starting and is connecting a team to Slack        |
| booted         | the service is starting and has connected a team to Slack        |
| stopping       | the service is about to disconnect a team from Slack             |
| stopped        | the service has disconnected a team from Slack                   |
| starting       | the service is (re)connecting a team to Slack                    |
| started        | the service has (re)connected a team to Slack                    |
| deactivating   | a team is being deactivated                                      |
| deactivated    | a team has been deactivated                                      |

The Add to Slack button also allows for an optional 
state
 parameter that will be returned on completion of the request. The 
creating
 and 
created
 callbacks include an options hash where this value can be accessed (to check for forgery attacks for instance).
ruby
auth = OpenSSL::HMAC.hexdigest("SHA256", "key", "data")

html
 ... 

ruby
instance = SlackRubyBotServer::Service.instance
instance.on :creating do |team, error, options|
  raise "Unauthorized response" unless options[:state] == auth
end


Service Timers

You can introduce custom behavior into the service lifecycle on a timer. For example, check whether a team's trial has expired, or periodically cleanup data.

Note that unlike callbacks, timers are global for the entire service.
instance = SlackRubyBotServer::Service.instance

instance.every :hour do
  Team.each do |team|
    begin
      # do something with every team once an hour
    rescue StandardError
    end
  end
end
instance.every :minute do
called every minute
end
instance.every :second do
called every second
end
instance.every 30 do
called every 30 seconds
end

Extensions

A number of extensions use service manager callbacks and service timers to implement useful functionality.



slack-ruby-bot-server-events: Easily handle Slack slash commands, interactive buttons and events.

slack-ruby-bot-server-mailchimp: Subscribes new bot users to a Mailchimp mailing list.

slack-ruby-bot-server-stripe: Enables paid bots with trial periods and commerce through Stripe.

slack-ruby-bot-server-rtm: Create RTM Slack bots.


Service Class

You can override the service class to handle additional methods.
class MyService < SlackRubyBotServer::Service
  def url
    'https://www.example.com'
  end
end

SlackRubyBotServer.configure do |config|
  config.service_class = MyService
end
SlackRubyBotServer::Service.instance # MyService
SlackRubyBotServer::Service.instance.url # https://www.example.com

HTML Templates

This library provides a default HTML template and JS scripts that implement the "Add to Slack" button workflow. Customize your pages by adding a 
public
 directory in your application and starting with a index.html.erb template. The application's 
views
 and 
public
 folders are loaded by default.

You can add to or override template paths as follows.
SlackRubyBotServer.configure do |config|
  config.view_paths << File.expand_path(File.join(__dir__, 'public'))
end

Access Tokens

By default the implementation of Team stores the value of the token with all the requested OAuth scopes in both 
token
 and 
activated_user_access_token
 (for backwards compatibility), along with 
oauth_version
 and 
oauth_scope
. If a legacy Slack bot integration 
bot_access_token
 is present, it is stored as 
token
, and 
activated_user_access_token
 is the token that has all the requested OAuth scopes.

Sample Bots Using Slack Ruby Bot Server

Slack Bots with Granular Permissions



slack-ruby-bot-server-events-sample, a generic sample

slack-rails-bot-starter, an all-in-one Rails starter kit


Legacy Slack Bots



slack-ruby-bot-server-sample, a generic sample

slack-sup, see sup.playplay.io


slack-gamebot, see www.playplay.io


slack-market, see market.playplay.io


slack-shellbot, see shell.playplay.io


slack-api-explorer, see api-explorer.playplay.io


slack-strava, see slava.playplay.io


slack-arena, see arena.playplay.io



Copyright & License

Copyright Daniel Doubrovkine and Contributors, 2015-2020

MIT License