Derive system URI from default URI (#1398)

To facilitate using session on a remote instance, ensure the system_uri
configuration attribute is by default derived from the default uri
provided or constructed based on other settings, so that it contains any
host and transport settings.

lib/vagrant-libvirt/config.rb

@@ -840,7 +840,6 @@ module VagrantPlugins
         @management_network_pci_slot = nil if @management_network_pci_slot == UNSET_VALUE
         @management_network_domain = nil if @management_network_domain == UNSET_VALUE
         @management_network_mtu = nil if @management_network_mtu == UNSET_VALUE
-        @system_uri      = 'qemu:///system' if @system_uri == UNSET_VALUE
 
         # Domain specific settings.
         @title = '' if @title == UNSET_VALUE
@@ -1066,6 +1065,10 @@ module VagrantPlugins
         # Parse uri to extract individual components
         uri = _parse_uri(@uri)
 
+        system_uri = uri.dup
+        system_uri.path = '/system'
+        @system_uri = system_uri.to_s if @system_uri == UNSET_VALUE
+
         # only set @connect_via_ssh if not explicitly to avoid overriding
         # and allow an error to occur if the @uri and @connect_via_ssh disagree
         @connect_via_ssh = uri.scheme.include? "ssh" if @connect_via_ssh == UNSET_VALUE

spec/unit/config_spec.rb

@@ -338,6 +338,54 @@ describe VagrantPlugins::ProviderLibvirt::Config do
       end
     end
 
+    context '@system_uri' do
+      [
+        # system uri
+        [ # transport and hostname
+          {:uri => "qemu+ssh://localhost/session"},
+          {:uri => "qemu+ssh://localhost/session", :system_uri => "qemu+ssh://localhost/system"},
+        ],
+        [ # explicitly set
+          {:qemu_use_session => true, :system_uri => "custom://remote/system"},
+          {:uri => "qemu:///session", :system_uri => "custom://remote/system"},
+        ],
+      ].each do |inputs, outputs, options|
+        opts = {}
+        opts.merge!(options) if options
+
+        it "should handle inputs #{inputs} with env (#{opts[:env]})" do
+          # allow some of these to fail for now if marked as such
+          if !opts[:allow_failure].nil?
+            pending(opts[:allow_failure])
+          end
+
+          if !opts[:setup].nil?
+            opts[:setup].apply_binding(binding)
+          end
+
+          inputs.each do |k, v|
+            subject.instance_variable_set("@#{k}", v)
+          end
+
+          if !opts[:env].nil?
+            opts[:env].each do |k, v|
+              fake_env[k] = v
+            end
+          end
+
+          subject.finalize!
+
+          # ensure failed output indicates which settings are incorrect in the failed test
+          got = subject.instance_variables.each_with_object({}) do |name, hash|
+            if outputs.key?(name.to_s[1..-1].to_sym)
+              hash["#{name.to_s[1..-1]}".to_sym] =subject.instance_variable_get(name)
+            end
+          end
+          expect(got).to eq(outputs)
+        end
+      end
+    end
+
     context '@proxy_command' do
       before(:example) do
         stub_const("ENV", fake_env)

spec/unit/driver_spec.rb

@@ -80,15 +80,15 @@ describe VagrantPlugins::ProviderLibvirt::Driver do
     # system_uri should be 'qemu+ssh://user@remote1/system'
     # and not 'qemu:///system'.
     it 'should configure a separate connection per machine' do
-      expect(Libvirt).to receive(:open_read_only).with('qemu:///system').and_return(system_connection1)
-      expect(Libvirt).to receive(:open_read_only).with('qemu:///system').and_return(system_connection2)
+      expect(Libvirt).to receive(:open_read_only).with('qemu+ssh://user@remote1/system').and_return(system_connection1)
+      expect(Libvirt).to receive(:open_read_only).with('qemu+ssh://vms@remote2/system').and_return(system_connection2)
 
       expect(machine.provider.driver.system_connection).to eq(system_connection1)
       expect(machine2.provider.driver.system_connection).to eq(system_connection2)
     end
 
     it 'should configure the connection once' do
-      expect(Libvirt).to receive(:open_read_only).with('qemu:///system').and_return(system_connection1)
+      expect(Libvirt).to receive(:open_read_only).with('qemu+ssh://user@remote1/system').and_return(system_connection1)
 
       expect(machine.provider.driver.system_connection).to eq(system_connection1)
       expect(machine.provider.driver.system_connection).to eq(system_connection1)