Class: Lono::Param::Generator

Inherits:
Object
  • Object
show all
Defined in:
lib/lono/param/generator.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, options) ⇒ Generator

Returns a new instance of Generator.



25
26
27
28
29
30
 
# File 'lib/lono/param/generator.rb', line 25

def initialize(name, options)
  @name = "#{Lono.env}/#{name}"
  @options = options
  @env_path = options[:path] || "#{Lono.config.params_path}/#{@name}.txt"
  @base_path = @env_path.sub("/#{Lono.env}/", "/base/")
end

Class Method Details

.generate_all(options) ⇒ Object 



2
3
4
5
6
7
8
9
10
 
# File 'lib/lono/param/generator.rb', line 2

def self.generate_all(options)
  puts "Generating parameter files:"

  params = param_names("base") + param_names(Lono.env)
  params.uniq.each do |name|
    param = Lono::Param::Generator.new(name, options)
    param.generate
  end
end

.param_names(folder) ⇒ Object

Returns param names Example: Given params:

params/base/a.txt params/base/b.txt params/base/c.txt

Returns:

param_names("base") => ["a", "b", "c"]



18
19
20
21
22
23
 
# File 'lib/lono/param/generator.rb', line 18

def self.param_names(folder)
  base_folder = "#{Lono.config.params_path}/#{folder}" # Example: "./params/base"
  Dir.glob("#{base_folder}/**/*.txt").map do |path|
    path.sub("#{base_folder}/", '').sub('.txt','')
  end
end

Instance Method Details

#context ⇒ Object

Context for ERB rendering. This is where we control what references get passed to the ERB rendering.



93
94
95
 
# File 'lib/lono/param/generator.rb', line 93

def context
  @context ||= Lono::Template::Context.new(@options)
end

#convert_to_cfn_format(contents, casing = :camel) ⇒ Object 



116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
 
# File 'lib/lono/param/generator.rb', line 116

def convert_to_cfn_format(contents, casing=:camel)
  lines = parse_contents(contents)

  # First use a Hash structure so that overlay env files will override
  # the base param file.
  data = {}
  lines.each do |line|
    key,value = line.strip.split("=").map {|x| x.strip}
    data[key] = value
  end

  # Now build up the aws json format for parameters
  params = []
  data.each do |key,value|
    param = if value == "use_previous_value"
              {
                "ParameterKey": key,
                "UsePreviousValue": true
              }
            elsif value
              {
                "ParameterKey": key,
                "ParameterValue": value
              }
            end
    if param
      param = param.to_snake_keys if casing == :underscore
      params << param
    end
  end
  params
end

#generate ⇒ Object 



32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
 
# File 'lib/lono/param/generator.rb', line 32

def generate
  # useful option for lono cfn
  return if @options[:allow_no_file] && !source_exist?

  if source_exist?
    contents = process_erb
    data = convert_to_cfn_format(contents)
    json = JSON.pretty_generate(data)
    write_output(json)
    # Example: @name = stag/ecs/private
    #          pretty_name = ecs/private
    pretty_name = @name.sub("#{Lono.env}/", '')
    puts "  #{output_path}" unless @options[:mute]
  else
    puts "#{@base_path} or #{@env_path} could not be found?  Are you sure it exist?"
    exit 1
  end
  json
end

#output_path ⇒ Object 



149
150
151
152
 
# File 'lib/lono/param/generator.rb', line 149

def output_path
  name = @name.sub("#{Lono.env}/", "") # remove the Lono.env from the output path
  "#{Lono.config.output_path}/params/#{name}.json".sub(/\.\//,'')
end

#params(casing = :underscore) ⇒ Object

useful for when calling CloudFormation via the aws-sdk gem



53
54
55
56
57
58
59
 
# File 'lib/lono/param/generator.rb', line 53

def params(casing = :underscore)
  # useful option for lono cfn
  return {} if @options[:allow_no_file] && !source_exist?

  contents = process_erb
  convert_to_cfn_format(contents, casing)
end

#parse_contents(contents) ⇒ Object 



105
106
107
108
109
110
111
112
113
114
 
# File 'lib/lono/param/generator.rb', line 105

def parse_contents(contents)
  lines = contents.split("\n")
  # remove comment at the end of the line
  lines.map! { |l| l.sub(/#.*/,'').strip }
  # filter out commented lines
  lines = lines.reject { |l| l =~ /(^|\s)#/i }
  # filter out empty lines
  lines = lines.reject { |l| l.strip.empty? }
  lines
end

#process_erb ⇒ Object

Reads both the base source and env source and overlay the two Example 1:

params/base/mystack.txt - base path
params/prod/mystack.txt - env path

the base/mystack.txt gets combined with the prod/mystack.txt
it produces a final prod/mystack.txt

Example 2:

params/base/mystack.txt - base path

the base/mystack.txt is used to produced a prod/mystack.txt

Example 3:

params/prod/mystack.txt - env path

the prod/mystack.txt is used to produced a prod/mystack.txt



78
79
80
81
82
83
 
# File 'lib/lono/param/generator.rb', line 78

def process_erb
  contents = []
  contents << render_erb(@base_path)
  contents << render_erb(@env_path)
  contents.compact.join("\n")
end

#render_erb(path) ⇒ Object 



85
86
87
88
89
 
# File 'lib/lono/param/generator.rb', line 85

def render_erb(path)
  if File.exist?(path)
    RenderMePretty.result(path, context: context)
  end
end

#source_exist? ⇒ Boolean

Checks both base and source path for existing of the param file. Example:

params/base/mystack.txt - base path
params/prod/mystack.txt - source path

Returns:

  • (Boolean) 


101
102
103
 
# File 'lib/lono/param/generator.rb', line 101

def source_exist?
  File.exist?(@base_path) || File.exist?(@env_path)
end

#write_output(json) ⇒ Object 



154
155
156
157
158
 
# File 'lib/lono/param/generator.rb', line 154

def write_output(json)
  dir = File.dirname(output_path)
  FileUtils.mkdir_p(dir)
  IO.write(output_path, json)
end