Resize GKE node pools at once.

config.json

{
  "clusters": [
    {
      "project": "<project-name>",
      "name": "<cluster-name>",
      "zone": "<cluster-zone>",
      "nodePools": {
        "my-node-pool-1": 0,
        "my-node-pool-2": 1
      }
    }
  ]
}

gke-np.rb

require "json"
require "open3"

GCLOUD_CMD = "gcloud"

dry_run = false

if ARGV.size < 1
  $stderr.puts("Usage: ruby gke-np.rb $config_file")
  exit(-1)
end

conf = JSON.parse(File.read(ARGV[0]))

cols = conf['clusters'].map { |cluster| cluster['name'].size }.max
jobs = conf['clusters'].map { |cluster|
  name = cluster['name']
  name = " " * (cols - name.size) + name
  Thread.fork {
    cluster["nodePools"].each { |np, size|
      cmd = "#{GCLOUD_CMD} container clusters resize #{cluster['name']} -q --node-pool=#{np} --num-nodes=#{size} --project=#{cluster['project']} --zone=#{cluster['zone']}"
      puts("#{name}| #{cmd}")
      if dry_run
        next
      end
      result = Open3.popen2e(cmd) { |i, o, status|
        o.each_line { |row|
          puts("#{name}| #{row.chomp}")
        }
        status.value
      }
      unless result.success?
        $stderr.puts("#{name}| Failed to resize: status=#{result.exitstatus}")
      end
    }
  }
}

jobs.each { |job| job.join() }