A Procfile formatting script, written in Ruby

formatter.rb

#!/usr/bin/env ruby

require 'optparse'

def get_procfile_lines
  STDIN.read.split("\n")
end

def get_process_type_max_width(lines)
  processes = []
  lines.each do |line|
    processes << line if line.include?(":") && !line.start_with?("#")
  end

  max = 0
  processes.each do |line|
    left, _ = line.split(":")
    max = left.size if left.size > max
  end

  max
end

def ignore_line?(options, line)
  return true if line.start_with?("#") || line.empty?

  parts = line.split(":")

  # if the user has requested that we ignore the line, simply write it to stdout
  return true if !options[:ignored_process_types].nil? && options[:ignored_process_types].include?(parts[0])

  false
end

options = {}
OptionParser.new do |opts|
  opts.banner = "Usage: cat ./Procfile.dev | procfile_formatter.rb [options]"
  opts.on('-i', '--ignore NAME1,NAME2,NAME3', "ignored process types, e.g. 'web' or 'sidekiq'") { |v| options[:ignored_process_types] = v.split(",") }
end.parse!

lines = get_procfile_lines
process_type_max_width = get_process_type_max_width(lines)

lines.each do |line|
  if ignore_line?(options, line)
    puts line
    next
  end

  # note that there may be more than one colon in line
  parts = line.split(":")

  # construct the command portion of the line
  command = parts[1..].join(":").strip.gsub(/\s+/, " ")

  # an array of environment variable-setting strings, e.g. ["FOO=1", "BAR=abc"]
  environment_variables = []

  # all other parts of the command, e.g. ["env", "bundle", "exec", "rake"]
  others = []

  command.split(" ").each do |part|
    # if the part isn't obviously an environment variable, append it to 'others'
    unless part.include?("=") && part.split("=")[0] == part.split("=")[0].upcase
      others << part
      next
    end

    environment_variables << part
  end

  left = "#{parts[0]}:".ljust(process_type_max_width+1, " ")
  right = "#{others.join(" ")} #{environment_variables.sort.join(" ")}"

  puts "#{left} #{right}".strip
end

usage.md

Procfile Formatter

Usage

Given the following Procfile:

# /tmp/Procfile.example

web: bundle exec puma -C ./config/puma.rb

# Resque Scheduler
resque_scheduler: env TERM_CHILD=1 RESQUE_TERM_TIMEOUT=10 bundle exec rake environment resque:scheduler

# RabbitMQ message consumption
foo_processor: env USE_SHARED_DB=true JOB_KLASS=FooJob QUEUE_NAME=foo_jobs bundle exec rake rabbitmq_to_resque_reader BINDING_KEYS='meta.foo.#'
bar_processor: env USE_SHARED_DB=true QUEUE_NAME=bar_jobs JOB_KLASS=BarJob  bundle exec rake rabbitmq_to_resque_reader BINDING_KEYS='meta.bar.#'

# Resque worker processes
foo_worker: env bundle exec rake environment resqutils:work QUEUE=foo_jobs RESQUE_TERM_TIMEOUT=60 TERM_CHILD=1 USE_DATABASE=false
bar_worker:      env bundle exec rake environment resqutils:work QUEUE=bar_jobs TERM_CHILD=1 USE_DATABASE=false RESQUE_TERM_TIMEOUT=60 

When you run the following command:

$ cat /tmp/Procfile.example | ./formatter.rb

...you will see the following output:

# /tmp/Procfile.example

web:              bundle exec puma -C ./config/puma.rb

# Resque Scheduler
resque_scheduler: env bundle exec rake environment resque:scheduler RESQUE_TERM_TIMEOUT=10 TERM_CHILD=1

# RabbitMQ message consumption
foo_processor:    env bundle exec rake rabbitmq_to_resque_reader BINDING_KEYS='meta.foo.#' JOB_KLASS=FooJob QUEUE_NAME=foo_jobs USE_SHARED_DB=true
bar_processor:    env bundle exec rake rabbitmq_to_resque_reader BINDING_KEYS='meta.bar.#' JOB_KLASS=BarJob QUEUE_NAME=bar_jobs USE_SHARED_DB=true

# Resque worker processes
foo_worker:       env bundle exec rake environment resqutils:work QUEUE=foo_jobs RESQUE_TERM_TIMEOUT=60 TERM_CHILD=1 USE_DATABASE=false
bar_worker:       env bundle exec rake environment resqutils:work QUEUE=bar_jobs RESQUE_TERM_TIMEOUT=60 TERM_CHILD=1 USE_DATABASE=false