refactor cadvisor client

Author: yaacov

examples/cadvisor.rb

@@ -0,0 +1,21 @@
+require 'prometheus/api_client'
+
+# returns a client for cadvisor node data ( for node instance 'example.com' )
+prometheus = Prometheus::ApiClient::Cadvisor::Node.new(
+  instance: 'example.com',
+  url: 'http://example.com:8080',
+)
+
+prometheus.query_range(
+  query: 'sum(container_cpu_usage_seconds_total)',
+  start: '2017-08-07T06:10:30.781Z',
+  end:   '2017-08-07T06:14:30.781Z',
+  step:  '120s',
+)
+
+# will result in a hash containing the results data struct:
+#
+# {"resultType"=>"matrix", "result"=>[{"metric"=>{}, "values"=>
+#    [[1502086230.781, "314016.35813638807"],
+#    [1502086350.781, "5125.822337834"],
+#    [1502086470.781, "314093.6892872209"]]}]}

lib/prometheus/api_client/cadvisor.rb

@@ -8,29 +8,42 @@ module ApiClient
     # Client contains the implementation for a Prometheus compatible api_client,
     # With special labels for the cadvisor job.
     module Cadvisor
+      # A client with special labels for cadvisor metrics
+      class CadvisorClient < Client
+        # Add labels to simple query variables.
+        #
+        # Example:
+        #     "cpu_usage" => "cpu_usage{labels...}"
+        #     "sum(cpu_usage)" => "sum(cpu_usage{labels...})"
+        #     "rate(cpu_usage[5m])" => "rate(cpu_usage{labels...}[5m])"
+        #
+        # Note:
+        #     Not supporting more complex queries.
+        def update_query(query, labels)
+          query.sub(/(?<r>\[.+\])?(?<f>[)])?$/, "{#{labels}}\\k<r>\\k<f>")
+        end
+
+        # Issues a get request to the low level client.
+        # Update the query options to use specific labels
+        def get(command, options)
+          options[:query] = update_query(options[:query], @labels)
+          @client.get(command, options)
+        end
+      end
+
       # A client with special labels for node cadvisor metrics
-      class Node < Client
+      class Node < CadvisorClient
         def initialize(options = {})
           instance = options[:instance]
 
           @labels = "job=\"kubernetes-cadvisor\",instance=\"#{instance}\"," \
             'id="/"'
           super(options)
         end
-
-        def query(options)
-          options[:query] = update_query(options[:query], @labels)
-          super(options)
-        end
-
-        def query_range(options)
-          options[:query] = update_query(options[:query], @labels)
-          super(options)
-        end
       end
 
       # A client with special labels for pod cadvisor metrics
-      class Pod < Client
+      class Pod < CadvisorClient
         def initialize(options = {})
           pod_name = options[:pod_name]
           namespace = options[:namespace] || 'default'
@@ -39,20 +52,10 @@ def initialize(options = {})
             "pod_name=\"#{pod_name}\",container_name=\"POD\""
           super(options)
         end
-
-        def query(options)
-          options[:query] = update_query(options[:query], @labels)
-          super(options)
-        end
-
-        def query_range(options)
-          options[:query] = update_query(options[:query], @labels)
-          super(options)
-        end
       end
 
       # A client with special labels for container cadvisor metrics
-      class Container < Client
+      class Container < CadvisorClient
         def initialize(options = {})
           container_name = args[:container_name]
           pod_name = args[:pod_name]
@@ -62,16 +65,6 @@ def initialize(options = {})
             "pod_name=\"#{pod_name}\",container_name=\"#{container_name}\""
           super(options)
         end
-
-        def query(options)
-          options[:query] = update_query(options[:query], @labels)
-          super(options)
-        end
-
-        def query_range(options)
-          options[:query] = update_query(options[:query], @labels)
-          super(options)
-        end
       end
     end
   end

lib/prometheus/api_client/client.rb

@@ -105,19 +105,6 @@ def run_command(command, options)
         raise RequestError, 'Bad response from server'
       end
 
-      # Add labels to simple query variables.
-      #
-      # Example:
-      #     "cpu_usage" => "cpu_usage{labels...}"
-      #     "sum(cpu_usage)" => "sum(cpu_usage{labels...})"
-      #     "rate(cpu_usage[5m])" => "rate(cpu_usage{labels...}[5m])"
-      #
-      # Note:
-      #     Not supporting more complex queries.
-      def update_query(query, labels)
-        query.sub(/(?<r>\[.+\])?(?<f>[)])?$/, "{#{labels}}\\k<r>\\k<f>")
-      end
-
       # Helper function to evalueate the low level proxy option
       def faraday_proxy(options)
         options[:http_proxy_uri] if options[:http_proxy_uri]

lib/prometheus/api_client/version.rb

@@ -2,6 +2,6 @@
 
 module Prometheus
   module ApiClient
-    VERSION = '0.3.2'
+    VERSION = '0.3.3'
   end
 end