Class: CMDB::FileSource

Inherits:
Object
  • Object
show all
Defined in:
lib/cmdb/file_source.rb

Overview

Data source that is backed by a YAML file that lives in the filesystem. The name of the YAML file becomes the top-level key under which all values in the YAML are exposed, preserving their exact structure as parsed by YAML.

Examples:

Use my.yml as a CMDB source

source = FileSource.new('/tmp/my.yml') # contains a top-level stanza named "database"
source['my']['database']['host'] # => 'db1-1.example.com'

Class Attribute Summary collapse

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(filename, root = nil, prefix = File.basename(filename, '.*')) ⇒ FileSource

Construct a new FileSource from an input YML file.

Parameters:

  • filename (String, Pathname) —

    path to a YAML file

  • root (String) (defaults to: nil) —

    optional subpath in data to “mount”

  • prefix (String) (defaults to: File.basename(filename, '.*')) —

    optional prefix of

Raises:

  • (BadData) —

    if the file’s content is malformed



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# File 'lib/cmdb/file_source.rb', line 34

def initialize(filename, root = nil, prefix = File.basename(filename, '.*'))
  @data = {}
  @prefix = prefix
  filename = File.expand_path(filename)
  @url = URI.parse("file://#{filename}")
  @extension = File.extname(filename)
  raw_bytes = File.read(filename)
  raw_data  = nil

  begin
    case @extension
    when /jso?n?$/i
      raw_data = JSON.load(raw_bytes)
    when /ya?ml$/i
      raw_data = YAML.load(raw_bytes)
    else
      raise BadData.new(url, 'file with unknown extension; expected js(on) or y(a)ml')
    end
  rescue StandardError
    raise BadData.new(url, 'CMDB data file')
  end

  raw_data = raw_data[root] if !root.nil? && raw_data.key?(root)
  flatten(raw_data, @prefix, @data)
end

Class Attribute Details

.base_directories ⇒ Object

Returns the value of attribute base_directories.



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# File 'lib/cmdb/file_source.rb', line 21

def base_directories
  @base_directories
end

Instance Attribute Details

#prefix ⇒ URI (readonly)

Returns a file:// URL describing where this source’s data comes from.

Returns:

  • (URI) —

    a file:// URL describing where this source’s data comes from



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# File 'lib/cmdb/file_source.rb', line 14

def prefix
  @prefix
end

#url ⇒ URI (readonly)

Returns a file:// URL describing where this source’s data comes from.

Returns:

  • (URI) —

    a file:// URL describing where this source’s data comes from



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# File 'lib/cmdb/file_source.rb', line 14

def url
  @url
end

Instance Method Details

#each_pair {|key, value| ... } ⇒ Object

Enumerate the keys in this source, and their values.

Yields:

  • every key/value in the source

Yield Parameters:

  • key (String)
  • value (Object) 


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# File 'lib/cmdb/file_source.rb', line 72

def each_pair(&_block)
  # Strip the prefix in the key and call the block
  @data.each_pair { |k, v| yield(k.split("#{@prefix}.").last, v) }
end

#get(key) ⇒ nil, ...

Get the value of key.

Returns:

  • (nil, String, Numeric, TrueClass, FalseClass, Array) —

    the key’s value, or nil if not found



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# File 'lib/cmdb/file_source.rb', line 63

def get(key)
  @data[key]
end