(PUP-9076) Do not push nil on server context

and fail if none of the servers in `server_list` are reachable

Author: melissa

lib/puppet/configurer.rb

@@ -222,8 +222,7 @@ def run(options = {})
           found = find_functional_server()
           server = found[:server]
           if server.nil?
-            Puppet.warning _("Could not select a functional puppet master")
-            server = [nil, nil]
+            raise Puppet::Error, _("Could not select a functional puppet master from server_list: '%{server_list}'") % { server_list: Puppet.settings[:server_list] }
           end
           Puppet.override(:server => server[0], :serverport => server[1]) do
             if !server.first.nil?

spec/unit/configurer_spec.rb

@@ -1027,17 +1027,15 @@ def expects_neither_new_or_cached_catalog
       @agent.run
     end
 
-    it "should fallback to an empty server when failover fails" do
+    it "should error when no servers in 'server_list' are reachable" do
       Puppet.settings[:server_list] = ["myserver:123"]
       pool = Puppet::Network::HTTP::Pool.new(Puppet[:http_keepalive_timeout])
       Puppet::Network::HTTP::Pool.expects(:new).returns(pool)
       Puppet.expects(:override).with({:http_pool => pool}).yields
       Puppet.expects(:override).with({:server => "myserver", :serverport => '123'}).yields
-      Puppet.expects(:override).with({:server => nil, :serverport => nil}).yields
       error = Net::HTTPError.new(400, 'dummy server communication error')
       Puppet::Node.indirection.expects(:find).raises(error)
-      @agent.expects(:run_internal).returns(nil)
-      @agent.run
+      expect{ @agent.run }.to raise_error(Puppet::Error, /Could not select a functional puppet master from server_list/)
     end
 
     it "should not make multiple node requets when the server is found" do