Class: Constancy::Config

Inherits:
Object
  • Object
show all
Defined in:
lib/constancy/config.rb

Constant Summary collapse

CONFIG_FILENAMES = 
%w( constancy.yml )
VALID_CONFIG_KEYS = 
%w( sync consul vault constancy )
VALID_VAULT_KEY_PATTERNS = 
[ %r{^vault\.[A-Za-z][A-Za-z0-9_-]*$}, %r{^vault$} ]
VALID_CONFIG_KEY_PATTERNS = 
VALID_VAULT_KEY_PATTERNS
VALID_CONSUL_CONFIG_KEYS = 
%w( url datacenter token_source )
VALID_VAULT_CONFIG_KEYS = 
%w( url consul_token_path consul_token_field )
VALID_CONSTANCY_CONFIG_KEYS = 
%w( verbose chomp delete color )
DEFAULT_CONSUL_URL = 
"http://localhost:8500"
DEFAULT_CONSUL_TOKEN_SOURCE = 
"none"
DEFAULT_VAULT_CONSUL_TOKEN_FIELD = 
"token"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path: nil, targets: nil, call_external_apis: true) ⇒ Config

Returns a new instance of Config.



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# File 'lib/constancy/config.rb', line 51

def initialize(path: nil, targets: nil, call_external_apis: true)
  if path.nil? or File.directory?(path)
    self.config_file = Constancy::Config.discover(dir: path)
  elsif File.exist?(path)
    self.config_file = path
  else
    raise Constancy::ConfigFileNotFound.new
  end

  if self.config_file.nil? or not File.exist?(self.config_file) or not File.readable?(self.config_file)
    raise Constancy::ConfigFileNotFound.new
  end

  self.config_file = File.expand_path(self.config_file)
  self.base_dir = File.dirname(self.config_file)
  self.target_allowlist = targets
  self.call_external_apis = call_external_apis
  parse!
end

Instance Attribute Details

#base_dir ⇒ Object

Returns the value of attribute base_dir.



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# File 'lib/constancy/config.rb', line 23

def base_dir
  @base_dir
end

#call_external_apis ⇒ Object

Returns the value of attribute call_external_apis.



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# File 'lib/constancy/config.rb', line 23

def call_external_apis
  @call_external_apis
end

#config_file ⇒ Object

Returns the value of attribute config_file.



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# File 'lib/constancy/config.rb', line 23

def config_file
  @config_file
end

#consul_token_sources ⇒ Object

Returns the value of attribute consul_token_sources.



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# File 'lib/constancy/config.rb', line 23

def consul_token_sources
  @consul_token_sources
end

#consul_url ⇒ Object

Returns the value of attribute consul_url.



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# File 'lib/constancy/config.rb', line 23

def consul_url
  @consul_url
end

#default_consul_token_source ⇒ Object

Returns the value of attribute default_consul_token_source.



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# File 'lib/constancy/config.rb', line 23

def default_consul_token_source
  @default_consul_token_source
end

#sync_targets ⇒ Object

Returns the value of attribute sync_targets.



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# File 'lib/constancy/config.rb', line 23

def sync_targets
  @sync_targets
end

#target_allowlist ⇒ Object

Returns the value of attribute target_allowlist.



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# File 'lib/constancy/config.rb', line 23

def target_allowlist
  @target_allowlist
end

Class Method Details

.discover(dir: nil) ⇒ Object

discover the nearest config file



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# File 'lib/constancy/config.rb', line 28

def discover(dir: nil)
  dir ||= Dir.pwd

  CONFIG_FILENAMES.each do |filename|
    full_path = File.join(dir, filename)
    if File.exist?(full_path)
      return full_path
    end
  end

  dir == "/" ? nil : self.discover(dir: File.dirname(dir))
end

.only_valid_config_keys!(keylist) ⇒ Object 



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# File 'lib/constancy/config.rb', line 41

def only_valid_config_keys!(keylist)
  (keylist - VALID_CONFIG_KEYS).each do |key|
    if not VALID_CONFIG_KEY_PATTERNS.find { |pattern| key =~ pattern }
      raise Constancy::ConfigFileInvalid.new("'#{key}' is not a valid configuration key")
    end
  end
  true
end

Instance Method Details

#chomp? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/constancy/config.rb', line 75

def chomp?
  @do_chomp
end

#color? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/constancy/config.rb', line 83

def color?
  @use_color
end

#delete? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/constancy/config.rb', line 79

def delete?
  @do_delete
end

#parse! ⇒ Object 



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# File 'lib/constancy/config.rb', line 93

def parse!
  raw = {}
  begin
    raw = YAML.load(ERB.new(File.read(self.config_file)).result)
  rescue
    raise Constancy::ConfigFileInvalid.new("Unable to parse config file as YAML")
  end

  if raw.is_a? FalseClass
    # this generally means an empty config file
    raw = {}
  end

  if not raw.is_a? Hash
    raise Constancy::ConfigFileInvalid.new("Config file must form a hash")
  end

  Constancy::Config.only_valid_config_keys!(raw.keys)

  self.consul_token_sources = {
    "none" => Constancy::PassiveTokenSource.new,
    "env" => Constancy::EnvTokenSource.new,
  }.merge(
    self.parse_vault_token_sources!(raw),
  )

  raw['consul'] ||= {}
  if not raw['consul'].is_a? Hash
    raise Constancy::ConfigFileInvalid.new("'consul' must be a hash")
  end

  if (raw['consul'].keys - VALID_CONSUL_CONFIG_KEYS) != []
    raise Constancy::ConfigFileInvalid.new("Only the following keys are valid in the consul config: #{VALID_CONSUL_CONFIG_KEYS.join(", ")}")
  end

  self.consul_url = raw['consul']['url'] || DEFAULT_CONSUL_URL
  srcname = raw['consul']['token_source'] || DEFAULT_CONSUL_TOKEN_SOURCE
  self.default_consul_token_source =
    self.consul_token_sources[srcname].tap do |src|
      if src.nil?
        raise Constancy::ConfigFileInvalid.new("Consul token source '#{consul_token_source}' is not defined")
      end
    end

  raw['constancy'] ||= {}
  if not raw['constancy'].is_a? Hash
    raise Constancy::ConfigFileInvalid.new("'constancy' must be a hash")
  end

  if (raw['constancy'].keys - VALID_CONSTANCY_CONFIG_KEYS) != []
    raise Constancy::ConfigFileInvalid.new("Only the following keys are valid in the 'constancy' config block: #{VALID_CONSTANCY_CONFIG_KEYS.join(", ")}")
  end

  # verbose: default false
  @is_verbose = raw['constancy']['verbose'] ? true : false
  if ENV['CONSTANCY_VERBOSE']
    @is_verbose = true
  end

  # chomp: default true
  if raw['constancy'].has_key?('chomp')
    @do_chomp = raw['constancy']['chomp'] ? true : false
  else
    @do_chomp = true
  end

  # delete: default false
  @do_delete = raw['constancy']['delete'] ? true : false

  raw['sync'] ||= []
  if not raw['sync'].is_a? Array
    raise Constancy::ConfigFileInvalid.new("'sync' must be an array")
  end

  # color: default true
  if raw['constancy'].has_key?('color')
    @use_color = raw['constancy']['color'] ? true : false
  else
    @use_color = true
  end

  self.sync_targets = []
  raw['sync'].each do |target|
    token_source = self.default_consul_token_source
    if target.is_a? Hash
      target['datacenter'] ||= raw['consul']['datacenter']
      if target['chomp'].nil?
        target['chomp'] = self.chomp?
      end
      if target['delete'].nil?
        target['delete'] = self.delete?
      end
      if not target['token_source'].nil?
        token_source = self.consul_token_sources[target['token_source']]
        if token_source.nil?
          raise Constancy::ConfigFileInvalid.new("Consul token source '#{target['token_source']}' is not defined")
        end
        target.delete('token_source')
      end
    end

    if not self.target_allowlist.nil?
      # unnamed targets cannot be allowlisted
      next if target['name'].nil?

      # named targets must be on the allowlist
      next if not self.target_allowlist.include?(target['name'])
    end

    # only try to fetch consul tokens if we are actually going to do work
    consul_token = if self.call_external_apis
                     token_source.consul_token
                   else
                     ""
                   end
    self.sync_targets << Constancy::SyncTarget.new(config: target, consul_url: consul_url, token_source: token_source, base_dir: self.base_dir, call_external_apis: self.call_external_apis)
  end
end

#parse_vault_token_sources!(raw) ⇒ Object 



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# File 'lib/constancy/config.rb', line 87

def parse_vault_token_sources!(raw)
  raw.keys.select { |key| VALID_VAULT_KEY_PATTERNS.find { |pattern| key =~ pattern } }.collect do |key|
    [key, Constancy::VaultTokenSource.new(name: key, config: raw[key])]
  end.to_h
end

#verbose? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/constancy/config.rb', line 71

def verbose?
  @is_verbose
end