Graphite graph gen

graphite_graph.gemspec

@@ -16,4 +16,7 @@ Gem::Specification.new do |s|
   s.files         = `git ls-files`.split("\n")
   s.executables   = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
   s.require_paths = ["lib"]
+
+  s.add_dependency 'typhoeus'
+  s.add_dependency 'yajl-ruby'
 end

lib/graphite_graph/version.rb

@@ -1,3 +1,3 @@
 class GraphiteGraph
-  VERSION = "0.0.7"
+  VERSION = "0.0.8"
 end

lib/graphite_graph_gen.rb

@@ -0,0 +1,92 @@
+require 'typhoeus'
+require 'yajl'
+# A small DSL to assist in the creation of Graphite graphs
+# see https://github.com/ripienaar/graphite-graph-dsl/wiki
+# for full details
+class GraphiteGraphGenerator
+
+  def initialize(graphite_base, directory, graph_gen_file_name, info={})
+    @graphite_metrics_url = [graphite_base, "/metrics/index.json"].join
+    @graphs_dir = directory
+    @graph_gen_file = File.join(directory, graph_gen_file_name)
+    @info = info
+
+    @stats = []
+    @properties = {}
+    @general_text = ""
+
+    clean_old_generated_graphs
+    load_graph_gen
+    generate_graph_definitions
+  end
+
+  def load_graph_gen
+    self.instance_eval(File.read(@graph_gen_file)) unless @graph_gen_file == :none
+  end
+
+  def generator(options)
+    %w(context stats naming_pattern).each do |option|
+      raise "field_gen needs a #{option}" unless options.include?(option.to_sym)
+    end
+
+    options.each do |key, value|
+      if key.to_s.start_with? 'field_prop'
+        @properties[key.to_s.match(/^field_prop:(.*)$/)[1].to_sym] = value
+      else
+        self.instance_variable_set "@#{key}", value
+      end
+    end
+  end
+
+  def method_missing(method, *args)
+    @general_text << "#{method} "
+    @general_text << ( args[0].is_a?(Symbol) ? ":#{args[0]}" : "\"#{args[0]}\"" )
+    if args.length > 1
+      @general_text << ",\n#{args[1].to_s[1..-2]}\n"
+    end
+    @general_text << "\n\n"
+  end
+
+  def clean_old_generated_graphs
+    Dir.entries(@graphs_dir).select{|f| fn = File.join(@graphs_dir, f); File.delete(fn) if f.match(/gen.*\.graph$/)}
+  end
+
+  def generate_graph_definitions
+    metric_branches.each do |branch|
+      graph_name = extract_graph_name(branch)
+      graph_file_name = "gen_#{graph_name}.graph"
+      File.open(File.join(@graphs_dir, graph_file_name), 'w') {|f| f.write(graph_file_content(graph_name, branch)) }
+    end
+  end
+
+  def extract_graph_name(branch)
+    name_match = branch.match(@naming_pattern)
+    name_match ? name_match[1] : branch
+  end
+
+  def metric_branches
+    response = Typhoeus::Request.get(@graphite_metrics_url)
+    raise "Error fetching #{@graphite_metrics_url}. #{response.inspect}" unless response.success?
+    json = Yajl::Parser.parse(response.body) 
+    branches = json.join('|').scan(@context).uniq.map { |branch| branch[0] }
+  end
+
+  def graph_file_content(graph_name, branch)
+    graph_title = graph_name.gsub('_', ' ').gsub(' - ', ' ').gsub('.', ' - ').gsub('  ', ' ')      
+    graph_file_content = "title \"#{graph_title}\"\n\n" << @general_text      
+    @stats.uniq.each do |stat|
+      graph_file_content << "field :#{stat},\n" << ":data => \"#{full_metric(branch, stat)}\""
+      if @properties.length > 0
+        graph_file_content << ",\n#{@properties.to_s[1..-2]}\n"
+      end
+      graph_file_content << "\n\n"
+    end
+    graph_file_content
+  end
+
+  def full_metric(branch, stat)
+    full_metric = [branch, stat].join('.')
+    full_metric = @target_wrapper % full_metric if @target_wrapper 
+    full_metric
+  end
+end