Provide support for packaging into v2 format (#1360)

Support packaging multi disk machines however default to v1 format
unless v2 format is explicitly enabled. Output a warning to alert users
of the possible change in behaviour in the future.

Allows selecting the format to use via the environment, where use of v1
format with a multi disk machine will ignore the other disks.

spec/unit/action/package_domain_spec.rb

@@ -16,6 +16,8 @@ describe VagrantPlugins::ProviderLibvirt::Action::PackageDomain do
   let(:libvirt_domain) { double('libvirt_domain') }
   let(:servers) { double('servers') }
   let(:volumes) { double('volumes') }
+  let(:metadata_file) { double('file') }
+  let(:vagrantfile_file) { double('file') }
 
   describe '#call' do
     before do
@@ -54,10 +56,19 @@ describe VagrantPlugins::ProviderLibvirt::Action::PackageDomain do
         expect(subject).to receive(:`).with(/qemu-img info --output=json .*\/box.img/).and_return(
           { 'virtual-size': 5*1024*1024*1024 }.to_json
         )
+        expect(File).to receive(:write).with(
+          /.*\/metadata.json/,
+          <<-EOF.unindent
+          {
+            "provider": "libvirt",
+            "format": "qcow2",
+            "virtual_size": 5
+          }
+          EOF
+        )
+        expect(File).to receive(:write).with(/.*\/Vagrantfile/, /.*/)
 
         expect(subject.call(env)).to be_nil
-        expect(File.exist?(File.join(temp_dir, 'metadata.json'))).to eq(true)
-        expect(File.exist?(File.join(temp_dir, 'Vagrantfile'))).to eq(true)
       end
     end
 
@@ -85,6 +96,170 @@ describe VagrantPlugins::ProviderLibvirt::Action::PackageDomain do
         expect(subject.call(env)).to be_nil
       end
     end
+
+    context 'when detecting the format' do
+      let(:root_disk) { double('libvirt_domain_disk') }
+      let(:disk2) { double('libvirt_additional_disk') }
+      let(:fake_env) { Hash.new }
+
+      before do
+        allow(root_disk).to receive(:name).and_return('default_domain.img')
+        allow(disk2).to receive(:name).and_return('disk2.img')
+        allow(libvirt_domain).to receive(:name).and_return('default_domain')
+      end
+
+      context 'with two disks' do
+        before do
+          allow(domain).to receive(:volumes).and_return([root_disk, disk2])
+        end
+
+        it 'should emit a warning' do
+          expect(ui).to receive(:info).with('Packaging domain...')
+          expect(ui).to receive(:warn).with(/Detected more than one volume for machine.*\n.*/)
+          expect(subject).to receive(:package_v1)
+
+          expect(subject.call(env)).to be_nil
+        end
+      end
+
+      context 'with format set to v1' do
+        before do
+          allow(domain).to receive(:volumes).and_return([root_disk])
+          stub_const("ENV", fake_env)
+          fake_env['VAGRANT_LIBVIRT_BOX_FORMAT_VERSION'] = "v1"
+        end
+
+        it 'should call v1 packaging' do
+          expect(ui).to receive(:info).with('Packaging domain...')
+          expect(subject).to receive(:package_v1)
+
+          expect(subject.call(env)).to be_nil
+        end
+      end
+
+      context 'with format set to v2' do
+        before do
+          allow(domain).to receive(:volumes).and_return([root_disk])
+          stub_const("ENV", fake_env)
+          fake_env['VAGRANT_LIBVIRT_BOX_FORMAT_VERSION'] = "v2"
+        end
+
+        it 'should call v1 packaging' do
+          expect(ui).to receive(:info).with('Packaging domain...')
+          expect(subject).to receive(:package_v2)
+
+          expect(subject.call(env)).to be_nil
+        end
+      end
+
+      context 'with invalid format' do
+        before do
+          allow(domain).to receive(:volumes).and_return([root_disk])
+          stub_const("ENV", fake_env)
+          fake_env['VAGRANT_LIBVIRT_BOX_FORMAT_VERSION'] = "bad format"
+        end
+
+        it 'should emit a warning and default to v1' do
+          expect(ui).to receive(:info).with('Packaging domain...')
+          expect(ui).to receive(:warn).with(/Unrecognized value for.*defaulting to v1/)
+          expect(subject).to receive(:package_v1)
+
+          expect(subject.call(env)).to be_nil
+        end
+      end
+    end
+
+    context 'with v2 format' do
+      let(:disk1) { double('libvirt_domain_disk') }
+      let(:disk2) { double('libvirt_additional_disk') }
+      let(:fake_env) { Hash.new }
+
+      before do
+        allow(disk1).to receive(:name).and_return('default_domain.img')
+        allow(disk2).to receive(:name).and_return('disk2.img')
+        allow(libvirt_domain).to receive(:name).and_return('default_domain')
+        allow(subject).to receive(:download_image).and_return(true).twice()
+
+        stub_const("ENV", fake_env)
+        fake_env['VAGRANT_LIBVIRT_BOX_FORMAT_VERSION'] = "v2"
+      end
+
+      context 'with 2 disks' do
+        before do
+          allow(domain).to receive(:volumes).and_return([disk1, disk2])
+        end
+
+        it 'should succeed' do
+          expect(ui).to receive(:info).with('Packaging domain...')
+          expect(ui).to receive(:info).with(/Downloading default_domain.img to .*\/box_1.img/)
+          expect(ui).to receive(:info).with('Image has backing image, copying image and rebasing ...')
+          expect(subject).to receive(:`).with(/qemu-img info .*\/box_1.img | grep 'backing file:' | cut -d ':' -f2/).and_return("some image")
+          expect(subject).to receive(:`).with(/qemu-img rebase -p -b "" .*\/box_1.img/)
+          expect(subject).to receive(:`).with(/virt-sysprep --no-logfile --operations .* -a .*\/box_1.img .*/)
+          expect(subject).to receive(:`).with(/virt-sparsify --in-place .*\/box_1.img/)
+          expect(ui).to receive(:info).with(/Downloading disk2.img to .*\/box_2.img/)
+          expect(ui).to receive(:info).with('Image has backing image, copying image and rebasing ...')
+          expect(subject).to receive(:`).with(/qemu-img info .*\/box_2.img | grep 'backing file:' | cut -d ':' -f2/).and_return("some image")
+          expect(subject).to receive(:`).with(/qemu-img rebase -p -b "" .*\/box_2.img/)
+          expect(subject).to receive(:`).with(/virt-sparsify --in-place .*\/box_2.img/)
+
+          expect(File).to receive(:write).with(
+            /.*\/metadata.json/,
+            <<-EOF.unindent.rstrip()
+            {
+              "provider": "libvirt",
+              "format": "qcow2",
+              "disks": [
+                {
+                  "path": "box_1.img"
+                },
+                {
+                  "path": "box_2.img"
+                }
+              ]
+            }
+            EOF
+          )
+          expect(File).to receive(:write).with(/.*\/Vagrantfile/, /.*/)
+
+          expect(subject.call(env)).to be_nil
+        end
+      end
+
+      context 'with 1 disk' do
+        before do
+          allow(domain).to receive(:volumes).and_return([disk1])
+        end
+
+        it 'should succeed' do
+          expect(ui).to receive(:info).with('Packaging domain...')
+          expect(ui).to receive(:info).with(/Downloading default_domain.img to .*\/box_1.img/)
+          expect(ui).to receive(:info).with('Image has backing image, copying image and rebasing ...')
+          expect(subject).to receive(:`).with(/qemu-img info .*\/box_1.img | grep 'backing file:' | cut -d ':' -f2/).and_return("some image")
+          expect(subject).to receive(:`).with(/qemu-img rebase -p -b "" .*\/box_1.img/)
+          expect(subject).to receive(:`).with(/virt-sysprep --no-logfile --operations .* -a .*\/box_1.img .*/)
+          expect(subject).to receive(:`).with(/virt-sparsify --in-place .*\/box_1.img/)
+
+          expect(File).to receive(:write).with(
+            /.*\/metadata.json/,
+            <<-EOF.unindent.rstrip()
+            {
+              "provider": "libvirt",
+              "format": "qcow2",
+              "disks": [
+                {
+                  "path": "box_1.img"
+                }
+              ]
+            }
+            EOF
+          )
+          expect(File).to receive(:write).with(/.*\/Vagrantfile/, /.*/)
+
+          expect(subject.call(env)).to be_nil
+        end
+      end
+    end
   end
 
   describe '#vagrantfile_content' do