Class: WavefrontCli::Base

Inherits:
Object
  • Object
show all
Includes:
Wavefront::Validators, Constants
Defined in:
lib/wavefront-cli/base.rb

Overview

Parent of all the CLI classes. This class uses metaprogramming techniques to try to make adding new CLI commands and sub-commands as simple as possible.

To define a subcommand ‘cmd’, you only need add it to the docopt description in the relevant section, and create a method ‘do_cmd’. The WavefrontCli::Base::dispatch() method will find it, and call it. If your subcommand has multiple words, like ‘delete tag’, your do method would be called do_delete_tag. The do_ methods are able to access the Wavefront SDK object as wf, and all docopt options as options.

Constant Summary

Constants included from Constants

Constants::ALL_PAGE_SIZE, Constants::DEFAULT_CONFIG, Constants::DEFAULT_OPTS, Constants::EVENT_STATE_DIR, Constants::HUMAN_TIME_FORMAT, Constants::HUMAN_TIME_FORMAT_MS, Constants::SEARCH_SPLIT

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Base

Returns a new instance of Base.



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# File 'lib/wavefront-cli/base.rb', line 30

def initialize(options)
  @options = options
  sdk_class = _sdk_class
  @klass_word = sdk_class.split('::').last.downcase
  validate_input

  options_and_exit if options[:help]

  require_sdk_class
  @klass = Object.const_get(sdk_class)

  send(:post_initialize, options) if respond_to?(:post_initialize)
end

Instance Attribute Details

#klass ⇒ Object

Returns the value of attribute klass.



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# File 'lib/wavefront-cli/base.rb', line 25

def klass
  @klass
end

#klass_word ⇒ Object

Returns the value of attribute klass_word.



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# File 'lib/wavefront-cli/base.rb', line 25

def klass_word
  @klass_word
end

#options ⇒ Object

Returns the value of attribute options.



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# File 'lib/wavefront-cli/base.rb', line 25

def options
  @options
end

#wf ⇒ Object

Returns the value of attribute wf.



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# File 'lib/wavefront-cli/base.rb', line 25

def wf
  @wf
end

Instance Method Details

#_sdk_class ⇒ Object

Normally we map the class name to a similar one in the SDK. Overriding this method lets you map to something else.



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# File 'lib/wavefront-cli/base.rb', line 51

def _sdk_class
  self.class.name.sub(/Cli/, '')
end

#cannot_noop! ⇒ Object

Operations which do require multiple operations cannot be perormed as a no-op. Drop in a call to this method for those things. The exception is caught in controller.rb

Raises:



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# File 'lib/wavefront-cli/base.rb', line 528

def cannot_noop!
  raise WavefrontCli::Exception::UnsupportedNoop if options[:noop]
end

#check_response_blocks(data) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 244

def check_response_blocks(data)
  %i[status response].each do |b|
    abort "no #{b} block in API response" unless data.respond_to?(b)
  end
end

#check_status(status) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 280

def check_status(status)
  status.respond_to?(:result) && status.result == 'OK'
end

#cli_output_class(output_format) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 310

def cli_output_class(output_format)
  require_relative File.join('output', output_format.to_s)
  Object.const_get(format('WavefrontOutput::%<class>s',
                          class: output_format.to_s.capitalize))
end

#conds_to_query(conds) ⇒ Array[Hash]

Turn a list of search conditions into an API query

Parameters:

Returns:



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# File 'lib/wavefront-cli/base.rb', line 477

def conds_to_query(conds)
  conds.map do |cond|
    key, value = cond.split(SEARCH_SPLIT, 2)
    { key: key, value: value }.merge(matching_method(cond))
  end
end

#descriptive_name ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 124

def descriptive_name
  klass_word
end

#dispatch ⇒ nil

Works out the user’s command by matching any options docopt has set to ‘true’ with any ‘do_’ method in the class. Then calls that method, and displays whatever it returns.

Returns:

  • (nil)

Raises:

  • WavefrontCli::Exception::UnhandledCommand if the command does not match a do_ method.



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# File 'lib/wavefront-cli/base.rb', line 178

def dispatch
  # Look through each deconstructed method name and see if the
  # user supplied an option for each component.  Call the first
  # one that matches. The order will ensure we match
  # "do_delete_tags" before we match "do_delete".
  #
  method_word_list.reverse_each do |w_list|
    if w_list.reject { |w| options[w.to_sym] }.empty?
      method = name_of_do_method(w_list)
      return display(public_send(method), method)
    end
  end

  if respond_to?(:do_default)
    return display(public_send(:do_default), :do_default)
  end

  raise WavefrontCli::Exception::UnhandledCommand
end

#display(data, method) ⇒ Object

Display a Ruby object as JSON, YAML, or human-readable. We provide a default method to format human-readable output, but you can override it by creating your own humanize_command_output method control how its output is handled by setting the response instance variable.

Parameters:

  • data (WavefrontResponse) —

    an object returned by a Wavefront SDK method. This will contain ‘response’ and ‘status’ structures.

  • method (String) —

    the name of the method which produced this output. Used to find a suitable humanize method.



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# File 'lib/wavefront-cli/base.rb', line 224

def display(data, method)
  if no_api_response.include?(method)
    return display_no_api_response(data, method)
  end

  exit if options[:noop]

  check_response_blocks(data)
  warning_message(data.status)
  status_error_handler(data, method)
  handle_response(data.response, format_var, method)
end

#display_api_error(status) ⇒ Object

Classes can provide methods which give the user information on a given error code. They are named #handle_errcode_xxx, and return a string.

Parameters:

  • status (Map) —

    status object from SDK response

Returns:

  • System exit



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# File 'lib/wavefront-cli/base.rb', line 256

def display_api_error(status)
  method = format('handle_errcode_%<code>s', code: status.code).to_sym

  msg = if respond_to?(method)
          send(method, status)
        else
          status.message || 'No further information'
        end

  abort format('ERROR: API code %<code>s. %<message>s.',
               code: status.code,
               message: msg.chomp('.')).fold(TW, 7)
end

#display_class ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 330

def display_class
  klass.name.sub('Wavefront', 'WavefrontDisplay')
end

#display_no_api_response(data, method) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 276

def display_no_api_response(data, method)
  handle_response(data, format_var, method)
end

#do_delete ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 403

def do_delete
  wf.delete(options[:'<id>'])
end

#do_describe ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 365

def do_describe
  wf.describe(options[:'<id>'])
end

#do_dump ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 369

def do_dump
  cannot_noop!

  case options[:format]
  when 'yaml'
    ok_exit dump_yaml
  when 'json'
    ok_exit dump_json
  else
    abort format("Dump format must be 'json' or 'yaml'. " \
                 "(Tried '%<format>s')", options)
  end
end

#do_import ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 398

def do_import
  require_relative 'subcommands/import'
  WavefrontCli::Subcommand::Import.new(self, options).run!
end

#do_list ⇒ Object

Below here are common methods. Most are used by most classes, but if they don’t match a command described in the docopt text, the dispatcher will never call them. So, there’s no harm inheriting unneeded things. Some classes override them.



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# File 'lib/wavefront-cli/base.rb', line 355

def do_list
  list = if options[:all]
           wf.list(ALL_PAGE_SIZE, :all)
         else
           wf.list(options[:offset] || 0, options[:limit] || 100)
         end

  respond_to?(:list_filter) ? list_filter(list) : list
end

#do_search(cond = ) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 435

def do_search(cond = options[:'<condition>'])
  require 'wavefront-sdk/search'
  wfs = Wavefront::Search.new(mk_creds, mk_opts)
  query = conds_to_query(cond)
  wfs.search(search_key, query, range_hash)
end

#do_set ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 429

def do_set
  cannot_noop!
  k, v = options[:'<key=value>'].split('=', 2)
  wf.update(options[:'<id>'], k => v)
end

#do_undelete ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 425

def do_undelete
  wf.undelete(options[:'<id>'])
end

#dump_json ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 387

def dump_json
  item_dump_call.to_json
end

#dump_yaml ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 383

def dump_yaml
  JSON.parse(item_dump_call.to_json).to_yaml
end

#extract_values(obj, key, aggr = []) ⇒ Array

A recursive function which fetches list of values from a nested hash. Used by WavefrontCli::Dashboard#do_queries rubocop:disable Metrics/MethodLength

Parameters:

  • obj (Object) —

    the thing to search

  • key (String, Symbol) —

    the key to search for

  • aggr (Array) (defaults to: []) —

    values of matched keys

Returns:



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# File 'lib/wavefront-cli/base.rb', line 540

def extract_values(obj, key, aggr = [])
  case obj.class
  when Hash
    obj.each_pair do |k, v|
      if k == key && !v.to_s.empty?
        aggr.<< v
      else
        extract_values(v, key, aggr)
      end
    end
  when Array
    obj.each { |e| extract_values(e, key, aggr) }
  end

  aggr
end

#failed_validation_message(input) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 118

def failed_validation_message(input)
  format("'%<value>s' is not a valid %<thing>s ID.",
         value: input,
         thing: descriptive_name)
end

#format_var ⇒ Symbol

To allow a user to default to different output formats for different object types, we are able to define a format for each class. instance, alertformat or proxyformat. This method returns such a symbol appropriate for the inheriting class.

Returns:

  • (Symbol) —

    name of the option or config-file key which sets the default output format for this class



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# File 'lib/wavefront-cli/base.rb', line 164

def format_var
  options[:format].to_sym
rescue NoMethodError
  :human
end

#handle_error(method, code) ⇒ Object

This gives us a chance to catch different errors in WavefrontDisplay classes. If nothing catches, them abort.



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# File 'lib/wavefront-cli/base.rb', line 287

def handle_error(method, code)
  k = load_display_class
  k.new({}, options).run_error([method, code].join('_'))
end

#handle_response(resp, format, method) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 292

def handle_response(resp, format, method)
  if format == :human
    k = load_display_class
    k.new(resp, options).run(method)
  else
    parseable_output(format, resp)
  end
end

#hcl_fields ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 321

def hcl_fields
  []
end

#import_to_create(raw) ⇒ Object

Most things will re-import with the POST method if you remove the ID.



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# File 'lib/wavefront-cli/base.rb', line 561

def import_to_create(raw)
  raw.each_with_object({}) do |(k, v), a|
    a[k.to_sym] = v unless k == :id
  end
rescue StandardError => e
  puts e if options[:debug]
  raise WavefrontCli::Exception::UnparseableInput
end

#item_dump_call ⇒ Object

Broken out into its own method because ‘users’ does not use pagination



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# File 'lib/wavefront-cli/base.rb', line 394

def item_dump_call
  wf.list(ALL_PAGE_SIZE, :all).response.items
end

#load_display_class ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 325

def load_display_class
  require_relative File.join('display', klass_word)
  Object.const_get(display_class)
end

#matching_method(cond) ⇒ Hash

rubocop:disable Metrics/MethodLength

Parameters:

  • cond (String) —

    a search condition, like “key=value”

Returns:

  • (Hash) —

    of matchingMethod and negated



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# File 'lib/wavefront-cli/base.rb', line 488

def matching_method(cond)
  case cond
  when /^\w+~/
    { matchingMethod: 'CONTAINS', negated: false }
  when /^\w+!~/
    { matchingMethod: 'CONTAINS', negated: true }
  when /^\w+=/
    { matchingMethod: 'EXACT', negated: false }
  when /^\w+!=/
    { matchingMethod: 'EXACT', negated: true }
  when /^\w+\^/
    { matchingMethod: 'STARTSWITH', negated: false }
  when /^\w+!\^/
    { matchingMethod: 'STARTSWITH', negated: true }
  else
    raise(WavefrontCli::Exception::UnparseableSearchPattern, cond)
  end
end

#method_word_list ⇒ Object

Take a list of do_ methods, remove the ‘do_’ from their name, and break them into arrays of ‘_’ separated words. The array is sorted by length, longest first.



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# File 'lib/wavefront-cli/base.rb', line 206

def method_word_list
  do_methods = methods.select { |m| m.to_s.start_with?('do_') }
  do_methods.map { |m| m.to_s.split('_')[1..-1] }.sort_by(&:length)
end

#mk_creds ⇒ Hash

Make a wavefront-sdk credentials object from standard options.

Returns:

  • (Hash) —

    containing token and endpoint.



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

def mk_creds
  { token: options[:token],
    endpoint: options[:endpoint],
    agent: "wavefront-cli-#{WF_CLI_VERSION}" }
end

#mk_opts ⇒ Hash

Make a common wavefront-sdk options object from standard CLI options. We force verbosity on for a noop, otherwise we get no output.

Returns:

  • (Hash) —

    containing debug, verbose, and noop.



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# File 'lib/wavefront-cli/base.rb', line 145

def mk_opts
  ret = { debug: options[:debug],
          noop: options[:noop] }

  ret[:verbose] = options[:noop] ? true : options[:verbose]

  ret.merge!(extra_options) if respond_to?(:extra_options)
  ret
end

#name_of_do_method(word_list) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 198

def name_of_do_method(word_list)
  (%w[do] + word_list).join('_')
end

#no_api_response ⇒ Array[String]

Some subcommands don’t make an API call, so they don’t return a Wavefront::Response object. You can override this method with something which returns an array of methods like that. They will bypass the usual response checking.

response

Returns:

  • (Array[String]) —

    methods which do not include an API



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# File 'lib/wavefront-cli/base.rb', line 63

def no_api_response
  []
end

#ok_exit(message) ⇒ Object

Print a message and exit 0



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# File 'lib/wavefront-cli/base.rb', line 73

def ok_exit(message)
  puts message
  exit 0
end

#one_or_all ⇒ Object

Return a detailed description of one item, if an ID has been given, or all items if it has not.



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# File 'lib/wavefront-cli/base.rb', line 511

def one_or_all
  if options[:'<id>']
    resp = wf.describe(options[:'<id>'])
    data = [resp.response]
  else
    options[:all] = true
    resp = do_list
    data = resp.response.items
  end

  [resp, data]
end

#options_and_exit ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 67

def options_and_exit
  ok_exit(options)
end

#parseable_output(output_format, resp) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 301

def parseable_output(output_format, resp)
  options[:class] = klass_word
  options[:hcl_fields] = hcl_fields
  cli_output_class(output_format).new(resp, options).run
rescue LoadError
  raise(WavefrontCli::Exception::UnsupportedOutput,
        unsupported_format_message(output_format))
end

#range_hash ⇒ Object

If the user has specified –all, override any limit and offset values

rubocop:disable Metrics/MethodLength



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# File 'lib/wavefront-cli/base.rb', line 446

def range_hash
  offset_key = :offset

  if options[:all]
    limit  = :all
    offset = ALL_PAGE_SIZE
  elsif options[:cursor]
    offset_key = :cursor
    limit = options[:limit]
    offset = options[:cursor]
  else
    limit  = options[:limit]
    offset = options[:offset]
  end

  { limit: limit, offset_key => offset }
end

#require_sdk_class ⇒ Object 



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

def require_sdk_class
  require File.join('wavefront-sdk', @klass_word)
end

#run ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 78

def run
  @wf = klass.new(mk_creds, mk_opts)
  dispatch
end

#search_key ⇒ Object

The search URI pattern doesn’t always match the command name, or class name. Override this method if this is the case.



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# File 'lib/wavefront-cli/base.rb', line 468

def search_key
  klass_word
end

#smart_delete(object_type = klass_word) ⇒ Object

Some objects support soft deleting. To handle that, call this method from do_delete



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# File 'lib/wavefront-cli/base.rb', line 410

def smart_delete(object_type = klass_word)
  cannot_noop!
  puts smart_delete_message(object_type)
  wf.delete(options[:'<id>'])
end

#smart_delete_message(object_type) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 416

def smart_delete_message(object_type)
  desc = wf.describe(options[:'<id>'])
  word = desc.ok? ? 'Soft' : 'Permanently'
  format("%<soft_or_hard>s deleting %<object>s '%<id>s'",
         soft_or_hard: word,
         object: object_type,
         id: options[:'<id>'])
end

#status_error_handler(data, method) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 237

def status_error_handler(data, method)
  return if check_status(data.status)

  handle_error(method, data.status.code) if format_var == :human
  display_api_error(data.status)
end

#unsupported_format_message(output_format) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 316

def unsupported_format_message(output_format)
  format("The '%<command>s' command does not support '%<format>s' output.",
         command: options[:class], format: output_format)
end

#validate_id ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 112

def validate_id
  send(validator_method, options[:'<id>'])
rescue validator_exception
  abort failed_validation_message(options[:'<id>'])
end

#validate_input ⇒ Object 



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

def validate_input
  validate_id if options[:'<id>']
  validate_tags if options[:'<tag>']
  extra_validation if respond_to?(:extra_validation)
end

#validate_opts ⇒ Object

There are things we need to have. If we don’t have them, stop the user right now. Also, if we’re in debug mode, print out a hash of options, which can be very useful when doing actual debugging. Some classes may have to override this method. The writer, for instance, uses a proxy and has no token.

Raises:



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# File 'lib/wavefront-cli/base.rb', line 340

def validate_opts
  unless options[:token]
    raise(WavefrontCli::Exception::CredentialError, 'Missing API token.')
  end

  return true if options[:endpoint]

  raise(WavefrontCli::Exception::CredentialError, 'Missing API endpoint.')
end

#validate_tags(key = :'<tag>') ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 103

def validate_tags(key = :'<tag>')
  Array(options[key]).each do |t|
    send(:wf_tag?, t)
  rescue Wavefront::Exception::InvalidTag
    raise(WavefrontCli::Exception::InvalidInput,
          "'#{t}' is not a valid tag.")
  end
end

#validator_exception ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 91

def validator_exception
  Object.const_get(
    "Wavefront::Exception::Invalid#{klass_word.capitalize}Id"
  )
end

#validator_method ⇒ Object

We normally validate with a predictable method name. Alert IDs are validated with #wf_alert_id? etc. If you need to change that, override this method.



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# File 'lib/wavefront-cli/base.rb', line 87

def validator_method
  "wf_#{klass_word}_id?".to_sym
end

#warning_message(status) ⇒ Object 



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# File 'lib/wavefront-cli/base.rb', line 270

def warning_message(status)
  return unless status.code.between?(201, 299)

  puts format("API WARNING: '%<message>s'.", message: status.message)
end