add cAdvisor class

Author: yaacov

README.md

@@ -36,7 +36,7 @@ prometheus.get(
 
 ```ruby
 # return a client for host http://example.com:9090/api/v1/
-prometheus = Prometheus::ApiClient.client('http://example.com:9090')
+prometheus = Prometheus::ApiClient.client(url: 'http://example.com:9090')
 ```
 
 #### Authentication proxy
@@ -45,7 +45,7 @@ If an authentication proxy ( e.g. oauth2 ) is used in a layer above the promethe
 
 ```ruby
 # return a client for host https://example.com/api/v1/ using a Bearer token "TopSecret"
-prometheus = Prometheus::ApiClient.client('https://example.com:443', credentials: {token: 'TopSecret'})
+prometheus = Prometheus::ApiClient.client(url: 'https://example.com:443', credentials: {token: 'TopSecret'})
 ```
 
 #### High level calls
@@ -55,8 +55,7 @@ prometheus = Prometheus::ApiClient.client('https://example.com:443', credentials
 # send a query request to server
 prometheus.query(
   :query => "sum(container_cpu_usage_seconds_total{container_name=\"prometheus-hgv4s\",job=\"kubernetes-nodes\"})",
-  :start => "2015-07-01T20:10:30.781Z",
-  :end   => "2015-07-02T20:10:30.781Z"
+  :time => "2015-07-01T20:10:30.781Z",
 )
 
 # send a query_range request to server
@@ -70,6 +69,23 @@ prometheus.query_range(
 # send a label request to server
 prometheus.label('__name__')
 ```
+
+#### cAdvisor specialize client
+
+```ruby
+
+# create a client for cAdvisor metrics of a Node instance 'example.com'
+prometheus = Prometheus::ApiClient::Cadvisor::Node.new(
+  instance: 'example.com',
+  url: 'http://example.com:8080',
+)
+
+# send a query request to server
+prometheus.query(
+  :query => "sum(container_cpu_usage_seconds_total)",
+  :time => "2015-07-01T20:10:30.781Z",
+)
+
 ## Tests
 
 Install necessary development gems with `bundle install` and run tests with

examples/authentication_proxy.rb

@@ -1,7 +1,7 @@
 require 'prometheus/api_client'
 
 # returns a client, with authentication proxy support
-prometheus = Prometheus::ApiClient.client('https://example.com:443',
+prometheus = Prometheus::ApiClient.client(url: 'https://example.com:443',
                                           credentials: { token: 'TopSecret' })
 
 prometheus.query(

examples/get_labels.rb

@@ -1,7 +1,7 @@
 require 'prometheus/api_client'
 
 # returns a client
-prometheus = Prometheus::ApiClient.client('http://example.com:8080')
+prometheus = Prometheus::ApiClient.client(url: 'http://example.com:8080')
 
 prometheus.label('job')
 

examples/get_metrics.rb

@@ -1,7 +1,7 @@
 require 'prometheus/api_client'
 
 # returns a client
-prometheus = Prometheus::ApiClient.client('http://example.com:8080')
+prometheus = Prometheus::ApiClient.client(url: 'http://example.com:8080')
 
 prometheus.query_range(
   query: 'container_cpu_usage_seconds_total{id="/"}',

lib/prometheus/api_client.rb

@@ -3,25 +3,13 @@
 require 'uri'
 require 'openssl'
 require 'prometheus/api_client/client'
+require 'prometheus/api_client/cadvisor'
 
 module Prometheus
   # Api Client is a ruby implementation for a Prometheus compatible api_client.
   module ApiClient
-    # Default paramters for creating default client
-    DEFAULT_ENTRYPOINT = 'http://localhost:9090'.freeze
-    DEFAULT_ARGS = {
-      path: '/api/v1/',
-      credentials: {},
-      options: {
-        open_timeout: 2,
-        timeout: 5,
-      },
-    }.freeze
-
     # Create a Prometheus API client:
     #
-    # @param [String] entrypoint The Prometheus server url.
-    #
     # @param [Hash] options
     # @option options [Hash] :url String base URL.
     # @option options [Hash] :params URI query unencoded key/value pairs.
@@ -31,50 +19,8 @@ module ApiClient
     # @option options [Hash] :proxy Proxy options.
     #
     # A default client is created if options is omitted.
-    def self.client(entrypoint = DEFAULT_ENTRYPOINT, options = {})
-      options = DEFAULT_ARGS.merge(options)
-
-      Client.new(
-        prometheus_args(entrypoint, options),
-      )
-    end
-
-    # Helper function to evalueate the low level proxy option
-    def self.prometheus_proxy(options)
-      options[:http_proxy_uri] if options[:http_proxy_uri]
-    end
-
-    # Helper function to evalueate the low level ssl option
-    def self.prometheus_verify_ssl(options)
-      return unless options[:verify_ssl]
-
-      {
-        verify: options[:verify_ssl] != OpenSSL::SSL::VERIFY_NONE,
-        cert_store: options[:ssl_cert_store],
-      }
-    end
-
-    # Helper function to evalueate the low level headers option
-    def self.prometheus_headers(credentials)
-      return unless credentials[:token]
-
-      {
-        Authorization: 'Bearer ' + credentials[:token].to_s,
-      }
-    end
-
-    # Helper function to create the args for the low level client
-    def self.prometheus_args(entrypoint, args = {})
-      {
-        url: entrypoint + args[:path],
-        proxy: prometheus_proxy(args[:options]),
-        ssl: prometheus_verify_ssl(args[:options]),
-        headers: prometheus_headers(args[:credentials]),
-        request: {
-          open_timeout: args[:options][:open_timeout],
-          timeout: args[:options][:timeout],
-        },
-      }
+    def self.client(options = {})
+      Client.new(options)
     end
   end
 end

lib/prometheus/api_client/cadvisor.rb

@@ -8,25 +8,25 @@ module ApiClient
     # Client contains the implementation for a Prometheus compatible api_client,
     # With special labels for the cadvisor job.
     module Cadvisor
-      # Add labels to simple query variables.
+      # Create a Prometheus API client:
       #
-      # Example:
-      #     "cpu_usage" => "cpu_usage{labels...}"
-      #     "sum(cpu_usage)" => "sum(cpu_usage{labels...})"
-      #     "rate(cpu_usage[5m])" => "rate(cpu_usage{labels...}[5m])"
+      # @param [Hash] options
+      # @option options [Hash] :url String base URL.
+      # @option options [Hash] :params URI query unencoded key/value pairs.
+      # @option options [Hash] :headers Unencoded HTTP header key/value pairs.
+      # @option options [Hash] :request Request options.
+      # @option options [Hash] :ssl SSL options.
+      # @option options [Hash] :proxy Proxy options.
       #
-      # Note:
-      #     Not supporting more complex queries.
-      def self.update_query(query, labels)
-        query.sub(/(?<r>\[.+\])?(?<f>[)])?$/, "{#{labels}}\\k<r>\\k<f>")
-      end
-
-      # A client with special labels for node cadvisor metrics
+      # A default client is created if options is omitted.
       class Node < Client
-        def initialize(instance, region = 'infra', zone = 'default', args = {})
+        def initialize(instance:, **options)
+          region = options[:region] || 'infra'
+          zone = options[:zone] || 'default'
+
           @labels = "job=\"kubernetes-cadvisor\",region=\"#{region}\"," \
             "zone=\"#{zone}\",instance=\"#{instance}\""
-          super(args)
+          super(options)
         end
 
         def query(options)
@@ -42,13 +42,15 @@ def query_range(options)
 
       # A client with special labels for pod cadvisor metrics
       class Pod < Client
-        def initialize(pod_name, namespace = 'default', region = 'infra',
-                       zone = 'default', args = {})
+        def initialize(pod_name:, **options)
+          namespace = options[:namespace] || 'default'
+          region = options[:region] || 'infra'
+          zone = options[:zone] || 'default'
 
           @labels = "job=\"kubernetes-cadvisor\",region=\"#{region}\"," \
             "zone=\"#{zone}\",namespace=\"#{namespace}\"," \
             "pod_name=\"#{pod_name}\",container_name=\"POD\""
-          super(args)
+          super(options)
         end
 
         def query(options)
@@ -64,13 +66,15 @@ def query_range(options)
 
       # A client with special labels for container cadvisor metrics
       class Container < Client
-        def initialize(container_name, pod_name, namespace = 'default',
-                       region = 'infra', args = {})
+        def initialize(container_name:, pod_name:, **options)
+          namespace = args[:namespace] || 'default'
+          region = options[:region] || 'infra'
+          zone = options[:zone] || 'default'
 
           @labels = "job=\"kubernetes-cadvisor\",region=\"#{region}\"," \
-            "namespace=\"#{namespace}\"," \
+            "zone=\"#{zone}\",namespace=\"#{namespace}\"," \
             "pod_name=\"#{pod_name}\",container_name=\"#{container_name}\""
-          super(args)
+          super(options)
         end
 
         def query(options)

lib/prometheus/api_client/client.rb

@@ -10,6 +10,17 @@ module ApiClient
     class Client
       class RequestError < StandardError; end
 
+      # Default paramters for creating default client
+      DEFAULT_ARGS = {
+        url: 'http://localhost:9090',
+        path: '/api/v1/',
+        credentials: {},
+        options: {
+          open_timeout: 2,
+          timeout: 5,
+        },
+      }.freeze
+
       # Create a Prometheus API client:
       #
       # @param [Hash] options
@@ -22,7 +33,11 @@ class RequestError < StandardError; end
       #
       # A default client is created if options is omitted.
       def initialize(options)
-        @client = Faraday.new(options)
+        options = DEFAULT_ARGS.merge(options)
+
+        @client = Faraday.new(
+          faraday_options(options),
+        )
       end
 
       # Evaluates an instant query at a single point in time:
@@ -61,7 +76,7 @@ def query_range(options)
       # @param [Hash] options
       #
       # No options used.
-      def targets(options)
+      def targets(options = {})
         run_command('targets', options)
       end
 
@@ -89,6 +104,57 @@ def run_command(command, options)
       rescue
         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]
+      end
+
+      # Helper function to evalueate the low level ssl option
+      def faraday_verify_ssl(options)
+        return unless options[:verify_ssl]
+
+        {
+          verify: options[:verify_ssl] != OpenSSL::SSL::VERIFY_NONE,
+          cert_store: options[:ssl_cert_store],
+        }
+      end
+
+      # Helper function to evalueate the low level headers option
+      def faraday_headers(credentials)
+        return unless credentials[:token]
+
+        {
+          Authorization: 'Bearer ' + credentials[:token].to_s,
+        }
+      end
+
+      # Helper function to create the args for the low level client
+      def faraday_options(options)
+        {
+          url: options[:url] + options[:path],
+          proxy: faraday_proxy(options[:options]),
+          ssl: faraday_verify_ssl(options[:options]),
+          headers: faraday_headers(options[:credentials]),
+          request: {
+            open_timeout: options[:options][:open_timeout],
+            timeout: options[:options][:timeout],
+          },
+        }
+      end
     end
   end
 end

lib/prometheus/api_client/version.rb

@@ -2,6 +2,6 @@
 
 module Prometheus
   module ApiClient
-    VERSION = '0.2.1'
+    VERSION = '0.2.10'
   end
 end