A CLI for Common G5 Kube Commands

kube_commands.rb

#!/usr/bin/env ruby

# Setup:
# 1) `gem install highline`
# 2) save this file to a local folder
# 3) rename the file to remove extension `mv kube_commands.rb kube_command`
# 4) change permissions `chmod 755 kube_commands`
# 5) link to your /usr/local/bin `ln -s $PWD/kube_command /usr/local/bin/`
# 6) in a new shell you should now be able to run `kube_commands`
# 7) add new commands and add to this gist

require 'highline'
# require 'pry'
require 'optparse'

Options = Struct.new(:env, :app, :container)

class Parser
  def self.parse
    args = Options.new

    opt_parser = OptionParser.new do |opts|
      opts.banner = 'Usage: kube_controls [options]'

      opts.on('-eENV', '--env=ENV', "Target environment i.e. ['rd-earth', 'rd-fire', 'rd-wind', 'default']") do |e|
        args.env = e
      end

      opts.on('-aAPP', '--app=APP', 'Target Application') do |a|
        args.app = a
      end

      opts.on('-cCONTAINER', '--container=CONTAINER', "Target Container i.e. ['rails-server', 'nginx-proxy']") do |c|
        args.container = c
      end

      opts.on('-h', '--help', 'Prints this help') do
        puts opts
        exit
      end
    end

    opt_parser.parse!
    args
  end
end

# Glorified CLI Decorator
class Chooser

  attr_reader :cli

  def initialize(cli)
    @cli = cli
  end

  def choose(what, items)
    puts "\n"
    if items.length == 1
      puts "Selected only #{what}: #{items.first}"
      items.first
    elsif items.length > 1
      cli.choose do |menu|
        menu.prompt = "Select #{what}:  "
        items.each do |item|
          menu.choice(item)
        end
      end
    else
      raise "Error: No items for: #{what}?"
    end
  end
end

options = Parser.parse
cli = HighLine.new
chooser = Chooser.new(cli)

HighLine::Menu.index_color = :rgb_77bbff

if options.env
  env = options.env
else
  envs = `kubectl get ns -o=custom-columns=NAME:.metadata.name`
  envs = envs.split(/\n/).drop(1)
  env = chooser.choose('Deploy Environment', envs)
end

if options.app
  selected_app = options.app
else
  deps = `kubectl get deployments --output=name --namespace #{env}`
  apps = deps.split(/\n/).map do |app|
    app[%r{/([a-zA-Z]*)-}, 1]
  end
  selected_app = chooser.choose('App', apps.uniq)
end

pods = `kubectl get pods -o=custom-columns=NAME:.metadata.name --namespace #{env}`
app_pods = pods.split(/\n/).select do |pod|
  pod.include?(selected_app)
end
selected_pod = chooser.choose('Pod', app_pods)

def append_container(ctx, chooser, options)
  selected_container = if options.container
    options.container
  else
    containers = `kubectl get pods #{ctx} -o jsonpath='{.spec.containers[*].name}'`
    containers = containers.split(/\s/)
    chooser.choose('Container', containers)
  end

  ctx += " -c #{selected_container}" if selected_container
  ctx
end

ctx = "#{selected_pod} --namespace #{env}"

puts "\n"
done = false
until done
  cli.choose do |menu|
    menu.prompt = 'Select Task:  '
    menu.choice(:logs) do
      ctx = append_container(ctx, chooser, options)
      exec("kubectl logs -f #{ctx}")
    end
    menu.choice(:"shell (use printenv to check ENV vars)") do
      ctx = append_container(ctx, chooser, options)
      exec("kubectl exec -it #{ctx} -- /bin/bash")
    end
    menu.choice(:attach) do
      ctx = append_container(ctx, chooser, options)
      exec("kubectl attach #{ctx}")
    end
    menu.choice(:rake) do 
      task = cli.ask('Enter rake task: ')
      `kubectl exec -it #{ctx} -- /bin/bash -c 'bin/#{task}'`
    end
    menu.choice(:describe) { puts `kubectl describe pod #{ctx}` }
    menu.choice(:apply) { `kubectl apply -f k8s/#{env}.yaml --namespace=#{env}` }
    menu.choice(:'restart (with patch)') do
      deps = `kubectl get deployments --output=name --namespace #{env}`
      deployments = deps.split(/\n/).select do |dep|
        dep.include?(selected_app)
      end
      patches = cli.choose do |menu|
        menu.prompt = "Select deployments to restart:\nAvailable Deployments: #{deployments} "
        menu.choice(:all) { deployments }
        menu.choice(:'change deployments') do
          cli.say('Provide a comma separated list of available deployment paths: ')
          cli.ask('Deployments:  (deployment/example1, deployment/example2) | ', ->(str) { str.split(/,\s*/) })
        end
        menu.default = :all
      end
      patches.each do |patch|
        `kubectl patch #{patch} -p '{"spec":{"template":{"metadata":{"annotations":{"forced-reload":"'$(date +%s)'"}}}}}' --namespace #{env}`
      end
    end
    menu.choice(:exit) do
      if !options.env || !options.app
        cli.say("kube_commands --env=#{env} --app=#{selected_app}")
      end
      done = true
    end
  end
end