abonas/kubeclient

# frozen_string_literal: true

module Kubeclient
  # Generates a bearer token for Google Cloud Platform.
  class GCPCommandCredentials
    class << self
      def token(config)
        require 'open3'
        require 'shellwords'
        require 'json'

        cmd = config['cmd-path']
        args = config['cmd-args']
        token_key = config['token-key']

        out, err, st = Open3.capture3(cmd, *args.split)

        raise "exec command failed: #{err}" unless st.success?

        extract_token(out, token_key)
      end

      private

      def extract_token(output, key)
        path =
          key
          .gsub(/\A{(.*)}\z/, '\\1') # {.foo.bar} -> .foo.bar
          .sub(/\A\./, '') # .foo.bar -> foo.bar
          .split('.')
        JSON.parse(output).dig(*path)
      end
    end
  end
end