Script to see image sizes in Docker Hub

docker-hub-images-info.rb

#!/usr/bin/env ruby

require "json"

case ARGV.size
when 1
  image = ARGV[0]
  limit = 20
when 2
  image = ARGV[0]
  limit = ARGV[1]
else
  STDERR.puts "Usage: docker-hub-images image [limit]"
  exit 1
end

if not image.include?("/")
  image = "library/" + image
end

curl_cmd = %w(curl -s --user-agent Firefox -G)
curl_cmd << "https://hub.docker.com/v2/repositories/#{image}/tags/"
curl_cmd << "-d" << "page_size=#{limit}"
curl_cmd << "-d" << "page=1"

resp = IO.popen(curl_cmd) do |io|
  JSON.parse(io.read)
end

count = resp["count"]

if not count
  jj resp
  exit 1
end

puts "Found #{count} images"

results = resp["results"].map do |image|
  [ image["name"], "#{image["full_size"] / 1024 / 1024} Mib" ]
end

name_length = results.map {|r| r[0].size }.max + 3

results.each_with_index do |image, index|
  print "%5d   " % (index + 1)
  print image[0].ljust(name_length)
  puts image[1]
end