kube-resource-stat.rb

#!/usr/bin/env ruby
require 'json'
require 'terminal-table'

def cpu_to_milli(cpu)
  if cpu =~ /\A(\d+)m\z/
    return $1.to_i
  end
  return cpu.to_i * 1000
end

def memory_to_mib(s)
  if s =~ /\A(\d+)Mi\z/
    return $1.to_i
  elsif s =~ /\A(\d+)Gi\z/
    return $1.to_i * 1024
  elsif s =~ /\A(\d+)Ki\z/
    return $1.to_i / 1024
  end
  raise "Invalid memory: #{s}"
end

nodes = {}
JSON.parse(`kubectl get nodes -ojson`)['items'].each do |n|
  nodes[n['metadata']['name']] = n
end

pods = JSON.parse(`kubectl get pod --all-namespaces -ojson`)['items']
pods.group_by do |pod|
  pod['spec']['nodeName']
end.each do |nodename, pods|
  puts ">>> #{nodename}"

  rows = []
  rows << ['namespace', 'name', 'phase', 'milli cpu', 'memory (MiB)']
  rows << :separator

  total_cpu = 0
  total_memory = 0
  pods.each do |pod|
    namespace = pod['metadata']['namespace']
    name = pod['metadata']['name']
    phase = pod['status']['phase']
    pod['spec']['containers'].each do |container|
      if container['resources'] && container['resources']['requests']
        requests = container['resources']['requests']
        if requests['cpu']
          cpu = cpu_to_milli(requests['cpu'])
          total_cpu += cpu
        end
        if requests['memory']
          memory = memory_to_mib(requests['memory'])
          total_memory += memory
        end
      end
      rows << [namespace, name, phase, cpu, memory]
    end
  end
  rows << :separator
  rows << ['total', '', '', total_cpu, total_memory]

  allocatable = nodes[nodename]['status']['allocatable']
  allocatable_cpu = cpu_to_milli(allocatable['cpu'])
  allocatable_memory = memory_to_mib(allocatable['memory'])
  rows << ['allocatable', '', '', allocatable_cpu, allocatable_memory]
  rows << ['remain', '', '', allocatable_cpu - total_cpu, allocatable_memory - total_memory]

  puts Terminal::Table.new(rows: rows)
  puts
end