collected_metric.rb in frankenstein-2.0.0

- old
+ new

@@ -63,10 +63,13 @@
     #   meet [the guidelines for metric naming](https://prometheus.io/docs/practices/naming/),
     #   unless you like being shunned at parties.
     #
     # @param docstring [#to_s] the descriptive help text for the metric.
     #
+    # @param labels [Array<Symbol>] the labels which all time series for this
+    #   metric must possess.
+    #
     # @param type [Symbol] what type of metric you're returning.  It's uncommon
     #   to want anything other than `:gauge` here (the default), because
     #   when you're collecting external data it's unlikely you'll be able to
     #   trust that your external data source will behave like a proper
     #   counter (or histogram or summary), but if you want the flexibility,
@@ -85,12 +88,12 @@
     #   metric will also be registered here, so you'll know if a collection
     #   fails.
     #
     # @param collector [Proc] the code to run on every scrape request.
     #
-    def initialize(name, docstring, type: :gauge, logger: Logger.new('/dev/null'), registry: Prometheus::Client.registry, &collector)
-      @validator = Prometheus::Client::LabelSetValidator.new
+    def initialize(name, docstring:, labels: [], type: :gauge, logger: Logger.new('/dev/null'), registry: Prometheus::Client.registry, &collector)
+      @validator = Prometheus::Client::LabelSetValidator.new(expected_labels: labels)
 
       validate_name(name)
       validate_docstring(docstring)
 
       @name = name
@@ -102,18 +105,18 @@
       @type      = type
       @logger    = logger
       @registry  = registry
       @collector = collector
 
-      @errors_metric = @registry.counter(:"#{@name}_collection_errors_total", "Errors encountered while collecting for #{@name}")
+      @errors_metric = @registry.counter(:"#{@name}_collection_errors_total", docstring: "Errors encountered while collecting for #{@name}")
       @registry.register(self)
     end
 
     # Retrieve the value for the given labelset.
     #
     def get(labels = {})
-      @validator.validate(labels)
+      @validator.validate_labelset!(labels)
 
       values[labels]
     end
 
     # Retrieve a complete set of labels and values for the metric.
@@ -124,10 +127,10 @@
           unless results.is_a?(Hash)
             @logger.error(progname) { "Collector proc did not return a hash, got #{results.inspect}" }
             @errors_metric.increment(class: "NotAHashError")
             return {}
           end
-          results.keys.each { |labelset| @validator.validate(labelset) }
+          results.keys.each { |labelset| @validator.validate_labelset!(labelset) }
         end
       rescue StandardError => ex
         @logger.error(progname) { (["Exception in collection: #{ex.message} (#{ex.class})"] + ex.backtrace).join("\n  ") }
         @errors_metric.increment(class: ex.class.to_s)
 