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
• 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. 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, v2.2.0 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. Add the mongoid gem in your Gemfile.

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 and pagy_cursor gems to your Gemfile. Currently supports ActiveRecord/Rails major versions 6.0, 6.1 and 7.0.

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

Configure the database connection in config/postgresql.yml.

default: &defaultadapter: postgresqlpool: 10timeout: 5000encoding: unicodedevelopment:
<<: *defaultdatabase: bot_developmenttest:
<<: *defaultdatabase: bot_testproduction:
<<: *defaultdatabase: bot

Establish a connection in your startup code.

yml=ERB.new(File.read(File.expand_path('config/postgresql.yml',__dir__))).resultdb_config=ifGem::Version.new(Psych::VERSION) >= Gem::Version.new('3.1.0.pre1')
::YAML.safe_load(yml,aliases: true)[ENV['RACK_ENV']]else
::YAML.safe_load(yml,[],[],true)[ENV['RACK_ENV']]endActiveRecord::Base.establish_connection(db_config)

OAuth Version and Scopes

Configure your app's OAuth version and scopes as needed by your application.

SlackRubyBotServer.configuredo |config|
config.oauth_version=:v2config.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.

classMyApp < SlackRubyBotServer::Appdefprepare!superdeactivate_sleepy_teams!endprivatedefdeactivate_sleepy_teams!Team.active.eachdo |team|
nextunlessteam.sleepy?team.deactivate!endendend

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.instanceinstance.on:started,:stoppeddo |team|
# team has been started or stoppedendinstance.on:createddo |team,error,options|
# a new team has been registeredendinstance.on:deactivateddo |team,error,options|
# an existing team has been deactivated in Slackendinstance.on:errordo |team,error,options|
# an error has occurredend

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).

auth=OpenSSL::HMAC.hexdigest("SHA256","key","data")

<ahref="<%= SlackRubyBotServer::Config.oauth_authorize_url %>?scope=<%= SlackRubyBotServer::Config.oauth_scope_s %>&client_id=<%= ENV['SLACK_CLIENT_ID'] %>&state=#{auth)"> ... </a>

instance=SlackRubyBotServer::Service.instanceinstance.on:creatingdo |team,error,options|
raise"Unauthorized response"unlessoptions[:state] == authend

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 clean-up data. Timers can run once on start (once_and_every) and start running after a certain period (every).

instance=SlackRubyBotServer::Service.instanceinstance.every:hourdoTeam.eachdo |team|
begin# do something with every team once an hourrescueStandardErrorendendendinstance.once_and_every:minutedo# called once on start, then every minuteendinstance.every:minutedo# called every minuteendinstance.every:seconddo# called every secondendinstance.every30do# called every 30 secondsend

Note that, unlike callbacks, timers are global for the entire service. Timers are independent, and a failing timer will not terminate other timers.

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.

Service Class

You can override the service class to handle additional methods.

classMyService < SlackRubyBotServer::Servicedefurl'https://www.example.com'endendSlackRubyBotServer.configuredo |config|
config.service_class=MyServiceendSlackRubyBotServer::Service.instance# MyServiceSlackRubyBotServer::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.configuredo |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-ruby-bot-server-events-sample, a generic sample
• slack-rails-bot-starter, an all-in-one Rails starter kit
• slack-sup2, see sup2.playplay.io
• slack-gamebot2, see gamebot2.playplay.io

Copyright & License

Copyright Daniel Doubrovkine and Contributors, 2015-2025

MIT License