Module: Kube::CLI

Defined in:
lib/kube/cli.rb

Class Method Summary collapse

Class Method Details

.commands ⇒ Object

All registered command names.



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# File 'lib/kube/cli.rb', line 26

def self.commands
  @commands.dup
end

.lookup(name) ⇒ Object

Look up a registered subcommand handler by name.



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# File 'lib/kube/cli.rb', line 20

def self.lookup(name)
  entry = @commands[name.to_s]
  entry&.fetch(:handler)
end

.print_help(io = $stdout) ⇒ Object 



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# File 'lib/kube/cli.rb', line 52

def self.print_help(io = $stdout)
  io.puts "Usage: kube <command> [args...]"
  io.puts
  io.puts "Commands:"

  max_width = @commands.keys.map(&:length).max || 0

  @commands.sort_by { |name, _| name }.each do |name, entry|
    if entry[:description]
      io.puts "  %-#{max_width}s  %s" % [name, entry[:description]]
    else
      io.puts "  #{name}"
    end
  end

  io.puts
  io.puts "Run 'kube <command> --help' for more information on a command."
end

.register(name, handler, description: nil) ⇒ Object

Register a subcommand.

Kube::CLI.register("cluster", handler)

name - the subcommand name (String) handler - any object that responds to .call(argv)

where argv is the remaining ARGV after the subcommand

description - short one-line description for help output



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# File 'lib/kube/cli.rb', line 15

def self.register(name, handler, description: nil)
  @commands[name.to_s] = { handler: handler, description: description }
end

.run(argv = ARGV) ⇒ Object

Run the CLI. Parses the first argument as the subcommand, passes the rest to the handler.



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# File 'lib/kube/cli.rb', line 32

def self.run(argv = ARGV)
  subcommand = argv.shift

  if subcommand.nil? || subcommand == "help" || subcommand == "--help" || subcommand == "-h"
    print_help
    return
  end

  handler = lookup(subcommand)

  if handler.nil?
    $stderr.puts "kube: unknown command '#{subcommand}'"
    $stderr.puts
    print_help($stderr)
    exit 1
  end

  handler.call(argv)
end