docker_info.rb

#!/usr/bin/env ruby
# frozen_string_literal: true
# encoding: utf-8
##########################################################
###
##  File: docker_info.rb
##  Desc: get some basic information on all docker containers
##  By:   Dewayne VanHoozer (dvanhoozer@gmail.com)
#

require 'amazing_print'  # Pretty print Ruby objects with proper indentation and colors
require 'json'           # STDLIB
require 'tty-table'      # A flexible and intuitive table generator
require 'tty-screen'     # Terminal screen size detection which works on Linux, OS X and Windows/Cygwin platforms and supports MRI, JRuby and Rubinius interpreters.

screen = TTY::Screen

header = [
  'Container ID',
  'Container Name',
  'Status',
  'Container IP:Port',
  'Host IP'
]

table = TTY::Table.new(header: header)


container_ids = `docker ps -a -q`.split("\n")

container_ids.each do |cid|
  details = JSON.parse(`docker inspect #{cid}`).first
  # ap details

  if details["HostConfig"]["PortBindings"].nil?
    port        = 'N/A'
  else
    key         = details["HostConfig"]["PortBindings"].keys.first
    port        = key.nil? ? 'N/A' : details["HostConfig"]["PortBindings"][key].first["HostPort"]
  end

  status      = details["State"]["Status"]
  name        = details["Name"][1,99]

  key         = details['NetworkSettings']['Networks'].keys.first
  ip_address  = details['NetworkSettings']['Networks'][key]["IPAddress"]

  if 'running' == status
    command = %Q(docker exec -it #{name} bash -c "ip route | fgrep default | cut -f 3 -d' '")
    host_ip = `#{command}`.chomp
  else
    host_ip = 'N/A'
  end

  table << [ cid, name, status, "#{ip_address}:#{port}", host_ip]

end # container_ids.each do |cid|


puts
puts table.render(:unicode, padding: [0,1]) # padding: 0 lines, 1 char on left and right

kb = Array.new

kb << [ "docker logs <container name>",
        "shows the log file of a container"
      ]

kb << [ "docker exec -it <container name> bash",
        "opens a bash shell on a running container"
      ]

kb << [ "docker (start|stop) <container name>",
        "starts or stops a container"
      ]

kb << [ "docker images",
        "shows all docker images on your workstation"
      ]

kb << [ "docker inspect <container name>",
        "show details about a container's configuration"
      ]

kb << [ "docker ps",
        "shows all currently running containers"
      ]

kb << [ "delete_docker_junk.rb --delete-containers",
        "Delete containers; faster rebuild with local images"
      ]

kb << [ "delete_docker_junk.rb --delete-images",
        "Delete docker images"
      ]

kb << [ "delete_docker_junk.rb --all",
        "Delete docker containers and images"
      ]

table = TTY::Table.new(['KnowledgeBase of Commands', 'Description'], kb)
puts table.render(:unicode,
                  border: {separator: :each_row},
                  width:          screen.width-4, # tty-table has bug with padding
                  resize:         true,
                  multiline:      false,  # tty-table has bug with multiline=true and padding
                  padding:        [0, 1], # 1 character on left and right
                 )