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

Hey, thank you for this creative way of reporting commands in Rails to slack.

I'm facing an issue that's preventing me from deploying this.

Heroku's build process seems to kick off a one-off dyno' in order to deploy the application, which satisfies the dyno_in_run_mode` check in the code.

But at the time of deployment, ENV['DEV_NAME'] isn't expected to be set. We're expecting the dev pass along a temporary environment variable whenever they start the rails console (eg: heroku run EXEC_USER_NAME=rahul rails console).

So, due to the missing DEV_NAME, the deployment fails because dyno_in_run_mode is true during deployment.

Is this an issue that you've come across?

Hi, Thanks for building this. I was just wondering how to get it to fire on the console load for the first time.

@rahul You're supposed to pass the env variable to the one-off dyno on Heroku. This means, as you found out, passing an env variable to the Heroku CLI.

@mzaragoza You can put it in the initializer. This code is executed at console boot if I remember well. Just after this line https://gist.github.com/AntoineAugusti/a379d4060da40e1ec4218a4e6e3974dc#file-console_spy_initializer-rb-L6 should do the trick.

@AntoineAugusti Thanks for your help.
I was wondering if there is a way to back multiple lines?

An example I type this into the console

def test
  puts 'test'
end

then console_spy returns with:

Command: end
Output: : test

I would like that the command would say that the Command would be something like

def test
  puts 'test'
end

Thanks