Post a message to 'alert' channel in Slack

Gemfille

gem 'json'
gem 'faye-websocket'
gem 'eventmachine'
gem 'slack-ruby-client'

lib|slack_module.rb

class SlackModule
  before_action :get_slack_client
  
  require 'slack-ruby-client'
  require 'json'
  
  def post_to_alert_channel
    index       = 'Index'
    description = 'Description'
    json = JSON.generate([
      {
        color:   '#ac3d54',
        pretext: '',
        title:   'Title',
        text:    '----------------------------',
        fields: [
          {
            title: 'Description',
            value: description,
            short: false
          },
          {
            title: 'Index',
            value: index,
            short: false
          }
        ]
      }
    ])

    @client.chat_postMessage(
      channel:     '#alert',  # To 'alert' channel
      text:        '@channel Alert',  # the notification type is '@channel'
      as_user:     false,
      attachments: json,
      username:    'Alert Bot chan',
      icon_emoji:  ':warning:',
      link_names:  '1'
    ) if Rails.env.production? || Rails.env.staging?
  end
  
  private
  
  def get_slack_client
    Slack.configure do |config|
      config.token = '**********'
    end
    @client = Slack::Web::Client.new
  end
end