Module: LogStash::Util::SettingsHelper

Defined in:
lib/logstash/util/settings_helper.rb

Overview

Settings have an implicit initialization life-cycle, this helper exists to aid with the reading the settings.

Defaults are read from “logstash/environment” SettingsHelper.pre_process - registers defaults unavailable from “logstash/environment” SettingsHelper.from_yaml - finds yaml based on “–path.settings” and updates defaults if needed. SettingsHelper.post_process - callback to re-calculate derived settings

The methods should be called in the above order before the settings are ready to be used.

Class Method Summary collapse

Class Method Details

.cli_help?(args) ⇒ Boolean

is the user asking for CLI help subcommand?

Returns:

  • (Boolean) 


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# File 'lib/logstash/util/settings_helper.rb', line 75

def self.cli_help?(args)
  # I know, double negative
  !(["--help", "-h"] & args).empty?
end

.fetch_settings_path(cli_args) ⇒ Object

where can I find the logstash.yml file?

  1. look for a “–path.settings path”

  2. look for a “–path.settings=path”

  3. check if the LS_SETTINGS_DIR environment variable is set

  4. return nil if not found



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# File 'lib/logstash/util/settings_helper.rb', line 61

def self.fetch_settings_path(cli_args)
  if i=cli_args.find_index("--path.settings")
    cli_args[i+1]
  elsif settings_arg = cli_args.find {|v| v.match(/--path.settings=/)}
    match = settings_arg.match(/--path.settings=(.*)/)
    match[1]
  elsif ENV['LS_SETTINGS_DIR']
    ENV['LS_SETTINGS_DIR']
  else
    nil
  end
end

.from_yaml(args) ⇒ Object

param args: The array of all the command line arguments. Used to find the “path.settings” to read the settings yaml. Return true if successful, false otherwise



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# File 'lib/logstash/util/settings_helper.rb', line 31

def self.from_yaml(args)
  settings_path = fetch_settings_path(args)

  LogStash::SETTINGS.set("path.settings", settings_path) if settings_path
  LogStash::SETTINGS.set("keystore.file", ::File.join(settings_path, "logstash.keystore")) if settings_path

  begin
    LogStash::SETTINGS.from_yaml(LogStash::SETTINGS.get("path.settings"))
  rescue Errno::ENOENT
    $stderr.puts "WARNING: Could not find logstash.yml which is typically located in $LS_HOME/config or /etc/logstash. You can specify the path using --path.settings. Continuing using the defaults"
  rescue => e
    # abort unless we're just looking for the help
    unless cli_help?(args)
      if e.kind_of?(Psych::Exception)
        yaml_file_path = ::File.join(LogStash::SETTINGS.get("path.settings"), "logstash.yml")
        $stderr.puts "ERROR: Failed to parse YAML file \"#{yaml_file_path}\". Please confirm if the YAML structure is valid (e.g. look for incorrect usage of whitespace or indentation). Aborting... parser_error=>#{e.message}"
      else
        $stderr.puts "ERROR: Failed to load settings file from \"path.settings\". Aborting... path.setting=#{LogStash::SETTINGS.get("path.settings")}, exception=#{e.class}, message=>#{e.message}"
      end
      return false
    end
  end
  return true
end

.post_process ⇒ Object

Ensure that any settings are re-calculated after loading yaml



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# File 'lib/logstash/util/settings_helper.rb', line 25

def self.post_process
  LogStash::SETTINGS.post_process
end

.pre_process ⇒ Object

The ‘path.settings` and `path.logs` can not be defined in “logstash/environment” since the `Environment::LOGSTASH_HOME` doesn’t exist unless launched via “bootstrap/environment”



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# File 'lib/logstash/util/settings_helper.rb', line 19

def self.pre_process
  LogStash::SETTINGS.register(LogStash::Setting::String.new("path.settings", ::File.join(LogStash::Environment::LOGSTASH_HOME, "config")))
  LogStash::SETTINGS.register(LogStash::Setting::String.new("path.logs", ::File.join(LogStash::Environment::LOGSTASH_HOME, "logs")))
end