Add a service to retrieve Geo node information

app/models/geo_node.rb

@@ -77,6 +77,10 @@ class GeoNode < ActiveRecord::Base
     geo_api_url("transfers/#{file_type}/#{file_id}")
   end
 
+  def status_url
+    URI.join(uri, "#{uri.path}/", "api/#{API::API.version}/geo/status").to_s
+  end
+
   def oauth_callback_url
     Gitlab::Routing.url_helpers.oauth_geo_callback_url(url_helper_args)
   end

app/services/geo/node_status_service.rb

+module Geo
+  class NodeStatusService
+    include HTTParty
+
+    # HTTParty timeout
+    default_timeout Gitlab.config.gitlab.webhook_timeout
+
+    def call(status_url)
+      response = self.class.get(status_url,
+                                headers: {
+                                  'Content-Type' => 'application/json',
+                                  'PRIVATE-TOKEN' => private_token
+                                })
+
+      keys   = GeoNode::Status.members.map(&:to_s)
+      values = response.parsed_response.values_at(*keys)
+      status = GeoNode::Status.new(*values)
+
+      [(response.code >= 200 && response.code < 300), status]
+    rescue HTTParty::Error, Errno::ECONNREFUSED => e
+      [false, GeoNode::Status.new(ActionView::Base.full_sanitizer.sanitize(e.message))]
+    end
+
+    private
+
+    def private_token
+      # TODO: should we ask admin user to be defined as part of configuration?
+      @private_token ||= User.find_by(admin: true).authentication_token
+    end
+  end
+end