Code for the blog article about Reporting console commands in Rails

## console_spy_initializer.rb
is_staging_or_prod = Rails.env.production? || Rails.env.staging?
dyno_in_run_mode = ENV.fetch('DYNO', 'nope').starts_with?('run')
dev_name = ENV.fetch('DEV_NAME', '')

if is_staging_or_prod && dyno_in_run_mode
  raise Drivy::Errors::DevNameNotSetError if dev_name.blank?

  # Override how printing to sdtout works by sending
  # the output of stdout to a Slack webhook also.
  # When writing commands in irb, irb prints to stdout
  class << STDOUT
    include Drivy::Console::ReportCommand
    alias :usual_write :write

    def write(string)
      usual_write(string)
      send_command_to_slack(dev_name, string)
    end
  end
end

## report_command.rb
module Drivy::Console::ReportCommand

  def send_command_to_slack(developer_name, command_output)
    return unless has_command? && has_output?(command_output)

    # Documentation is at https://api.slack.com/docs/message-attachments
    fields = [
      {
        title: "Command",
        value: wrap_command(read_command),
        short: true,
      },
      {
        title: "Output",
        value: wrap_command(parse_output(command_output)),
        short: false,
      },
      {
        title: "Developer",
        value: developer_name,
        short: true,
      }
    ]

    env_color, env_title = env_params

    params = {
      attachments: [
        {
          fields: fields,
          color: env_color,
          footer: "Console #{env_title} spy",
          footer_icon: "https://drivy-prod-static.s3.amazonaws.com/slack/spy-small.png",
          ts: Time.zone.now.to_i,
          mrkdwn_in: ["fields"],
        }
      ]
    }

    response = slack_client.post('', params)

    raise "Failed to notify Slack of console command, status: #{response.status}" unless response.success?
  end

  private

  def env_params
    if Rails.env.production?
      return ["#e74c3c", "production"] # red
    elsif Rails.env.staging?
      return ["#f1c40f", "staging"] # orange
    else
      return ["#2ecc71", "development"] # yellow
    end
  end

  def wrap_command(value)
    "```#{value}```"
  end

  def parse_output(command_output)
    command_output.gsub('=>', '').strip
  end

  def has_command?
    Readline::HISTORY.length >= 1
  end

  def has_output?(command_output)
    return false unless command_output.instance_of? String
    command_output.strip.start_with? "=>"
  end

  def read_command
    Readline::HISTORY[Readline::HISTORY.length-1]
  end

  def slack_client
    endpoint = ENV.fetch('SLACK_WEBHOOK_CONSOLE', '')
    raise "SLACK_WEBHOOK_CONSOLE is not defined" if endpoint.blank?

    Faraday.new(url: endpoint) do |c|
      c.request :json
      c.adapter Faraday.default_adapter
    end
  end
end