Use systemd to halt system if available

plugins/guests/linux/cap/halt.rb

@@ -1,10 +1,18 @@
+require 'vagrant/util/guest_inspection'
+
 module VagrantPlugins
   module GuestLinux
     module Cap
       class Halt
+        extend Vagrant::Util::GuestInspection::Linux
+
         def self.halt(machine)
           begin
-            machine.communicate.sudo("shutdown -h now")
+            if systemd?(machine.communicate)
+              machine.communicate.sudo("systemctl poweroff")
+            else
+              machine.communicate.sudo("shutdown -h now")
+            end
           rescue IOError, Vagrant::Errors::SSHDisconnected
             # Do nothing, because it probably means the machine shut down
             # and SSH connection was lost.

test/unit/plugins/guests/linux/cap/halt_test.rb

@@ -10,34 +10,57 @@ describe "VagrantPlugins::GuestLinux::Cap::Halt" do
   let(:machine) { double("machine") }
   let(:comm) { VagrantTests::DummyCommunicator::Communicator.new(machine) }
 
-  before do
-    allow(machine).to receive(:communicate).and_return(comm)
-  end
-
-  after do
-    comm.verify_expectations!
-  end
-
-  describe ".halt" do
-    let(:cap) { caps.get(:halt) }
-
-    it "runs the shutdown command" do
-      comm.expect_command("shutdown -h now")
-      cap.halt(machine)
+  context "systemd not enabled" do
+    before do
+      allow(machine).to receive(:communicate).and_return(comm)
+      allow(comm).to receive(:test).and_return(false)
     end
 
-    it "does not raise an IOError" do
-      comm.stub_command("shutdown -h now", raise: IOError)
-      expect {
-        cap.halt(machine)
-      }.to_not raise_error
+    after do
+      comm.verify_expectations!
     end
 
-    it "does not raise a SSHDisconnected" do
-      comm.stub_command("shutdown -h now", raise: Vagrant::Errors::SSHDisconnected)
-      expect {
+    describe ".halt" do
+      let(:cap) { caps.get(:halt) }
+
+      it "runs the shutdown command" do
+        comm.expect_command("shutdown -h now")
         cap.halt(machine)
-      }.to_not raise_error
+      end
+
+      it "does not raise an IOError" do
+        comm.stub_command("shutdown -h now", raise: IOError)
+        expect {
+          cap.halt(machine)
+        }.to_not raise_error
+      end
+
+      it "does not raise a SSHDisconnected" do
+        comm.stub_command("shutdown -h now", raise: Vagrant::Errors::SSHDisconnected)
+        expect {
+          cap.halt(machine)
+        }.to_not raise_error
+      end
+    end
+
+    context "systemd enabled" do
+      before do
+        allow(machine).to receive(:communicate).and_return(comm)
+        allow(comm).to receive(:test).and_return(true)
+      end
+
+      after do
+        comm.verify_expectations!
+      end
+
+      describe ".halt" do
+        let(:cap) { caps.get(:halt) }
+
+        it "runs the shutdown command" do
+          comm.expect_command("systemctl poweroff")
+          cap.halt(machine)
+        end
+      end
     end
   end
 end