Summarize terraform planning output

summarize-planning-output.rb

#!/usr/bin/ruby

ErrorIfNonEmpty = ARGV.delete('-e') != nil
RemoveColors = ARGV.delete('-c') != nil
HeadersOnly = ARGV.delete('-l') != nil

def isHeader(l)
	l.include? 'resource'
end
def isChange(l)
	l =~ %r{^ *(~|-|\+)[^-]}
end
def isPointless(l)
	l.include? '(known after apply)' and / +\+/ =~ l
end

$isPlanningFile = false
$foundActions = false
$foundError = false

ARGF.each_line do |l|
	if not $isPlanningFile
		$isPlanningFile = true if l.include? 'Refreshing Terraform state'
	elsif not $foundActions and not $foundError
		$foundActions = true if l.include? 'will perform'
		$foundError = true if l.include? 'Error'
	else
		withoutColor = l.gsub %r{\x1b\[[0-9;]*[a-zA-Z]}, ''  # Strip off vt100 control chars so we can parse the line (but retain them on `l` for output)

		if isHeader withoutColor
			puts (RemoveColors ? withoutColor : l).sub('resource "','').sub('" "','.').sub('" {','')
		elsif withoutColor.include? 'forces' and not HeadersOnly
			puts RemoveColors ? withoutColor : l
		elsif not HeadersOnly and isChange withoutColor and not isPointless(withoutColor)
			darkWhite = RemoveColors ? '' : "\x1b[2;37m"
			puts "#{darkWhite}#{withoutColor}"
		end
	end
end

unless $isPlanningFile
	$stderr.puts "Input file doesn't look like Terraform planning output... :\\"
	exit 4
end

if $foundError
	$stderr.puts "Plan failed :("
	exit 4
end

$stderr.puts "Nothing to do! :)" unless $foundActions
exit ($foundActions ? 1 : 0) if ErrorIfNonEmpty