Class: WavefrontCliController

Inherits:
Object
  • Object
show all
Defined in:
lib/wavefront-cli/controller.rb

Overview

Dynamically generate a CLI interface from files which describe each subcomand.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(args) ⇒ WavefrontCliController

Returns a new instance of WavefrontCliController.



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# File 'lib/wavefront-cli/controller.rb', line 21

def initialize(args)
  @args = args
  @cmds = load_commands
  @usage = docopt_hash
  cmd, opts = parse_args
  @opts = parse_opts(opts)
  pp @opts if @opts[:debug]
  hook = load_sdk(cmd, @opts)
  run_command(hook)
end

Instance Attribute Details

#args ⇒ Object (readonly)

Returns the value of attribute args.



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# File 'lib/wavefront-cli/controller.rb', line 19

def args
  @args
end

#cmds ⇒ Object (readonly)

Returns the value of attribute cmds.



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# File 'lib/wavefront-cli/controller.rb', line 19

def cmds
  @cmds
end

#opts ⇒ Object (readonly)

Returns the value of attribute opts.



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# File 'lib/wavefront-cli/controller.rb', line 19

def opts
  @opts
end

#tw ⇒ Object (readonly)

Returns the value of attribute tw.



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# File 'lib/wavefront-cli/controller.rb', line 19

def tw
  @tw
end

#usage ⇒ Object (readonly)

Returns the value of attribute usage.



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# File 'lib/wavefront-cli/controller.rb', line 19

def usage
  @usage
end

Instance Method Details

#conf_file ⇒ Pathname

The default config file path.

Returns:

  • (Pathname) —

    where we excpect to find a config file



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# File 'lib/wavefront-cli/controller.rb', line 120

def conf_file
  if ENV['HOME']
    Pathname.new(ENV['HOME']) + '.wavefront'
  else
    Pathname.new('/etc/wavefront/client.conf')
  end
end

#default_help ⇒ Object

What you see when you do ‘wavefront –help’



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# File 'lib/wavefront-cli/controller.rb', line 34

def default_help
  s = "Wavefront CLI\n\nUsage:\n  #{CMD} command [options]\n" \
      "  #{CMD} --version\n  #{CMD} --help\n\nCommands:\n"

  cmds.sort.each { |k, v| s.<< format("  %-18s %s\n", k, v.description) }
  s.<< "\nUse '#{CMD} <command> --help' for further information.\n"
end

#docopt_hash ⇒ Object

Make a hash of command descriptions for docopt.



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# File 'lib/wavefront-cli/controller.rb', line 44

def docopt_hash
  cmds.each_with_object(default: default_help) do |(k, v), ret|
    ret[k.to_sym] = v.docopt
  end
end

#import_command(f) ⇒ Object

Load a command description from a file. Each is in its own class

return [Class] new class object defining command.

Parameters:

  • f (Pathname) —

    path of file to load



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# File 'lib/wavefront-cli/controller.rb', line 109

def import_command(f)
  return if f.extname != '.rb' || f.basename.to_s == 'base.rb'
  k_name = f.basename.to_s[0..-4]
  require(CMD_DIR + k_name)
  Object.const_get("WavefrontCommand#{k_name.capitalize}").new
end

#load_commands ⇒ Object

Each command is defined in its own file. Dynamically load all those commands.



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# File 'lib/wavefront-cli/controller.rb', line 97

def load_commands
  CMD_DIR.children.each_with_object({}) do |f, ret|
    k = import_command(f)
    ret[k.word.to_sym] = k if k
  end
end

#load_sdk(cmd, opts) ⇒ Object

Get the SDK class we need to run the command we’ve been given.



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# File 'lib/wavefront-cli/controller.rb', line 75

def load_sdk(cmd, opts)
  require_relative File.join('.', cmds[cmd].sdk_file)
  Object.const_get('WavefrontCli').const_get(cmds[cmd].sdk_class).new(opts)
rescue WavefrontCli::Exception::UnhandledCommand
  abort 'Fatal error. Unsupported command.'
rescue => e
  p e
end

#parse_args ⇒ Object

Parse the input. The first Docopt.docopt handles the default options, the second works on the command.



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# File 'lib/wavefront-cli/controller.rb', line 53

def parse_args
  Docopt.docopt(usage[:default], version: WF_CLI_VERSION, argv: args)
rescue Docopt::Exit => e
  cmd = args.empty? ? nil : args.first.to_sym

  abort e.message unless usage.keys.include?(cmd)

  begin
    [cmd, sanitize_keys(Docopt.docopt(usage[cmd], argv: args))]
  rescue Docopt::DocoptLanguageError => e
    abort "mangled command description:\n#{e.message}"
  rescue Docopt::Exit => e
    abort e.message
  end
end

#parse_opts(o) ⇒ Object 



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# File 'lib/wavefront-cli/controller.rb', line 69

def parse_opts(o)
  WavefrontCli::OptHandler.new(conf_file, o).opts
end

#run_command(hook) ⇒ Object 



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# File 'lib/wavefront-cli/controller.rb', line 84

def run_command(hook)
  hook.validate_opts
  hook.run
rescue => e
  $stderr.puts "general error: #{e}"
  $stderr.puts "re-run with '-D' for stack trace." unless opts[:debug]
  $stderr.puts "Backtrace:\n\t#{e.backtrace.join("\n\t")}" if opts[:debug]
  abort
end

#sanitize_keys(h) ⇒ Object

Symbolize, and remove dashes from option keys

return [Hash] h with modified keys

Parameters:

  • h (Hash) —

    options hash



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# File 'lib/wavefront-cli/controller.rb', line 133

def sanitize_keys(h)
  h.each_with_object({}) { |(k, v), r| r[k.delete('-').to_sym] = v }
end