Add support for snapshots (#1456)

Builds on the work started by @randomvariable in #840 addressing the comments
left there.

Fixes: #529

Signed-off-by: Rodolfo Olivieri rodolfo.olivieri3@gmail.com

README.md

@@ -92,7 +92,7 @@ can help a lot :-)
 * Setup hostname and network interfaces.
 * Provision domains with any built-in Vagrant provisioner.
 * Synced folder support via `rsync`, `nfs`, `9p` or `virtiofs`.
-* Snapshots via [sahara](https://github.com/jedi4ever/sahara).
+* Snapshots 
 * Package caching via
   [vagrant-cachier](http://fgrehm.viewdocs.io/vagrant-cachier/).
 * Use boxes from other Vagrant providers via

lib/vagrant-libvirt/action.rb

@@ -40,6 +40,12 @@ module VagrantPlugins
       autoload :SetNameOfDomain, action_root.join('set_name_of_domain')
       autoload :SetBootOrder, action_root.join('set_boot_order')
       autoload :SetupComplete, action_root.join('cleanup_on_failure')
+      # Snapshot autoload
+      autoload :SnapshotDelete, action_root.join('snapshot_delete')
+      autoload :SnapshotSave, action_root.join('snapshot_save')
+      autoload :SnapshotRestore, action_root.join('snapshot_restore')
+
+
       # I don't think we need it anymore
       autoload :ShareFolders, action_root.join('share_folders')
       autoload :ShutdownDomain, action_root.join('shutdown_domain')
@@ -392,6 +398,48 @@ module VagrantPlugins
         end
       end
 
+      # This is the action that is primarily responsible for deleting a snapshot
+      def self.action_snapshot_delete
+        Vagrant::Action::Builder.new.tap do |b|
+          b.use ConfigValidate
+          b.use Call, IsCreated do |env, b2|
+            unless env[:result]
+              raise Vagrant::Errors::VMNotCreatedError
+            end
+
+            b2.use SnapshotDelete
+          end
+        end
+      end
+      
+      # This is the action that is primarily responsible for restoring a snapshot
+      def self.action_snapshot_restore
+        Vagrant::Action::Builder.new.tap do |b|
+          b.use ConfigValidate
+          b.use Call, IsCreated do |env, b2|
+            unless env[:result]
+              raise Vagrant::Errors::VMNotCreatedError
+            end
+            
+            b2.use SnapshotRestore
+          end
+        end
+      end
+
+      # This is the action that is primarily responsible for saving a snapshot
+      def self.action_snapshot_save
+        Vagrant::Action::Builder.new.tap do |b|
+          b.use ConfigValidate
+          b.use Call, IsCreated do |env, b2|
+            unless env[:result]
+              raise Vagrant::Errors::VMNotCreatedError
+            end
+            
+            b2.use SnapshotSave
+          end
+        end
+      end
+
     end
   end
 end

lib/vagrant-libvirt/action/destroy_domain.rb

@@ -34,7 +34,7 @@ module VagrantPlugins
               begin
                 libvirt_domain.lookup_snapshot_by_name(name).delete
               rescue => e
-                raise Errors::DeleteSnapshotError, error_message: e.message
+                raise Errors::SnapshotDeletionError, error_message: e.message
               end
             end
           rescue

lib/vagrant-libvirt/action/snapshot_delete.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module VagrantPlugins
+  module ProviderLibvirt
+    module Action
+      class SnapshotDelete
+        def initialize(app, env)
+          @app = app
+        end
+
+        def call(env)
+          env[:ui].info(I18n.t(
+            "vagrant.actions.vm.snapshot.deleting",
+            name: env[:snapshot_name]))
+          env[:machine].provider.driver.delete_snapshot(env[:machine], env[:snapshot_name])
+
+          env[:ui].success(I18n.t(
+            "vagrant.actions.vm.snapshot.deleted",
+            name: env[:snapshot_name]))
+
+          @app.call(env)
+        end
+      end
+    end
+  end
+end

lib/vagrant-libvirt/action/snapshot_restore.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module VagrantPlugins
+  module ProviderLibvirt
+    module Action
+      class SnapshotRestore
+        def initialize(app, env)
+          @app = app
+        end
+
+        def call(env)
+          env[:ui].info(I18n.t(
+            "vagrant.actions.vm.snapshot.restoring",
+            name: env[:snapshot_name]))
+          env[:machine].provider.driver.restore_snapshot(env[:machine], env[:snapshot_name])
+
+          @app.call(env)
+        end
+      end
+    end
+  end
+end

lib/vagrant-libvirt/action/snapshot_save.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module VagrantPlugins
+  module ProviderLibvirt
+    module Action
+      class SnapshotSave
+        def initialize(app, env)
+          @app = app
+        end
+
+        def call(env)
+          env[:ui].info(I18n.t(
+            "vagrant.actions.vm.snapshot.saving",
+            name: env[:snapshot_name]))
+          env[:machine].provider.driver.create_snapshot(
+            env[:machine], env[:snapshot_name])
+
+          env[:ui].success(I18n.t(
+            "vagrant.actions.vm.snapshot.saved",
+            name: env[:snapshot_name]))
+
+          @app.call(env)
+        end
+      end
+    end
+  end
+end

lib/vagrant-libvirt/cap/snapshots.rb

@@ -0,0 +1,12 @@
+module VagrantPlugins
+  module ProviderLibvirt
+    module Cap
+      class Snapshots
+        def self.snapshot_list(machine)
+          return if machine.state.id == :not_created
+          machine.provider.driver.list_snapshots(machine)
+        end
+      end
+    end
+  end
+end

lib/vagrant-libvirt/driver.rb

@@ -125,6 +125,58 @@ module VagrantPlugins
         ip_address
       end
 
+      def restore_snapshot(machine, snapshot_name)
+        domain = get_libvirt_domain(machine)
+        snapshot = get_snapshot_if_exists(machine, snapshot_name)
+        begin
+          # 4 is VIR_DOMAIN_SNAPSHOT_REVERT_FORCE
+          # needed due to https://bugzilla.redhat.com/show_bug.cgi?id=1006886
+          domain.revert_to_snapshot(snapshot, 4)
+        rescue Fog::Errors::Error => e
+          raise Errors::SnapshotReversionError, error_message: e.message
+        end
+      end
+
+      def list_snapshots(machine)
+        get_libvirt_domain(machine).list_snapshots
+      rescue Fog::Errors::Error => e
+        raise Errors::SnapshotListError, error_message: e.message
+      end
+
+      def delete_snapshot(machine, snapshot_name)
+        get_snapshot_if_exists(machine, snapshot_name).delete
+      rescue Errors::SnapshotMissing => e
+        raise Errors::SnapshotDeletionError, error_message: e.message
+      end
+
+      def create_new_snapshot(machine, snapshot_name)
+        snapshot_desc = <<-EOF
+        <domainsnapshot>
+          <name>#{snapshot_name}</name>
+          <description>Snapshot for vagrant sandbox</description>
+        </domainsnapshot>
+        EOF
+        get_libvirt_domain(machine).snapshot_create_xml(snapshot_desc)
+      rescue Fog::Errors::Error => e
+        raise Errors::SnapshotCreationError, error_message: e.message
+      end
+
+      def create_snapshot(machine, snapshot_name)
+        begin
+          delete_snapshot(machine, snapshot_name)
+        rescue Errors::SnapshotDeletionError
+        end
+        create_new_snapshot(machine, snapshot_name)
+      end
+
+      # if we can get snapshot description without exception it exists
+      def get_snapshot_if_exists(machine, snapshot_name)
+        snapshot = get_libvirt_domain(machine).lookup_snapshot_by_name(snapshot_name)
+        return snapshot if snapshot.xml_desc
+      rescue Libvirt::RetrieveError => e
+        raise Errors::SnapshotMissing, error_message: e.message
+      end
+
       def state(machine)
         # may be other error states with initial retreival we can't handle
         begin
@@ -216,6 +268,21 @@ module VagrantPlugins
         ip_address
       end
 
+      def get_libvirt_domain(machine)
+        begin
+          libvirt_domain = connection.client.lookup_domain_by_uuid(machine.id)
+        rescue Libvirt::RetrieveError => e
+          if e.libvirt_code == ProviderLibvirt::Util::ErrorCodes::VIR_ERR_NO_DOMAIN
+            @logger.debug("machine #{machine.name} not found #{e}.")
+            return nil
+          else
+            raise e
+          end
+        end
+
+        libvirt_domain
+      end
+
     end
   end
 end

lib/vagrant-libvirt/errors.rb

@@ -186,8 +186,24 @@ module VagrantPlugins
         error_key(:no_ip_address_error)
       end
 
-      class DeleteSnapshotError < VagrantLibvirtError
+      class SnapshotMissing < VagrantLibvirtError
-        error_key(:delete_snapshot_error)
+        error_key(:snapshot_missing)
+      end
+
+      class SnapshotDeletionError < VagrantLibvirtError
+        error_key(:snapshot_deletion_error)
+      end
+
+      class SnapshotListError < VagrantLibvirtError
+        error_key(:snapshot_list_error)
+      end
+      
+      class SnapshotCreationError < VagrantLibvirtError
+        error_key(:snapshot_creation_error)
+      end
+
+      class SnapshotReversionError < VagrantLibvirtError
+        error_key(:snapshot_reversion_error)
       end
 
       class SerialCannotCreatePathError < VagrantLibvirtError

lib/vagrant-libvirt/plugin.rb

@@ -51,6 +51,11 @@ module VagrantPlugins
         Cap::PublicAddress
       end
 
+      provider_capability(:libvirt, :snapshot_list) do
+        require_relative 'cap/snapshots'
+        Cap::Snapshots
+      end
+
       # lower priority than nfs or rsync
       # https://github.com/vagrant-libvirt/vagrant-libvirt/pull/170
       synced_folder('9p', 4) do

locales/en.yml

@@ -183,6 +183,16 @@ en:
       management_network_required: |-
         Management network can't be disabled when VM use box.
         Please fix your configuration and run vagrant again.
+      snapshot_deletion_error: |-
+        Error while deleting snapshot: %{error_message}.
+      snapshot_missing: |-
+        Snapshot not found: %{error_message}.
+      snapshot_list_error: |-
+        Cannot list snapshots: %{error_message}.
+      snapshot_creation_error: |-
+        Cannot create snapshot(s): %{error_message}.
+      snapshot_reversion_error: |-
+        Cannot revert snapshot(s): %{error_message}.      
       serial_cannot_create_path_error: |-
         Error creating path for serial port output log: %{path}
 

spec/unit/action_spec.rb

@@ -170,4 +170,92 @@ describe VagrantPlugins::ProviderLibvirt::Action do
       end
     end
   end
+  
+  describe '#action_snapshot_delete' do
+    context 'when not created' do
+      before do
+        allow_action_env_result(VagrantPlugins::ProviderLibvirt::Action::IsCreated, false)
+      end
+
+      it 'should cause an error' do
+        expect{ machine.action(:snapshot_delete, snapshot_opts: {})}.to raise_error(Vagrant::Errors::VMNotCreatedError)
+      end
+    end
+
+    context 'when created' do
+      before do
+        allow_action_env_result(VagrantPlugins::ProviderLibvirt::Action::IsCreated, true)
+      end
+
+      context 'when running' do
+        before do
+          allow_action_env_result(VagrantPlugins::ProviderLibvirt::Action::IsRunning, true)
+        end
+
+        it 'should call SnapshotDelete' do
+          expect_any_instance_of(VagrantPlugins::ProviderLibvirt::Action::SnapshotDelete).to receive(:call).and_return(0)
+          expect(machine.action(:snapshot_delete, snapshot_opts: {})).to match(hash_including({:action_name => :machine_action_snapshot_delete}))
+        end
+      end
+    end
+  end
+
+
+  describe '#action_snapshot_restore' do
+    context 'when not created' do
+      before do
+        allow_action_env_result(VagrantPlugins::ProviderLibvirt::Action::IsCreated, false)
+      end
+
+      it 'should cause an error' do
+        expect{ machine.action(:snapshot_restore, snapshot_opts: {})}.to raise_error(Vagrant::Errors::VMNotCreatedError)
+      end
+    end
+
+    context 'when created' do
+      before do
+        allow_action_env_result(VagrantPlugins::ProviderLibvirt::Action::IsCreated, true)
+      end
+
+      context 'when running' do
+        before do
+          allow_action_env_result(VagrantPlugins::ProviderLibvirt::Action::IsRunning, true)
+        end
+
+        it 'should call SnapshotRestore' do
+          expect_any_instance_of(VagrantPlugins::ProviderLibvirt::Action::SnapshotRestore).to receive(:call).and_return(0)
+          expect(machine.action(:snapshot_restore, snapshot_opts: {})).to match(hash_including({:action_name => :machine_action_snapshot_restore}))
+        end
+      end
+    end
+  end
+  
+  describe '#action_snapshot_save' do
+    context 'when not created' do
+      before do
+        allow_action_env_result(VagrantPlugins::ProviderLibvirt::Action::IsCreated, false)
+      end
+
+      it 'should cause an error' do
+        expect{ machine.action(:snapshot_save, snapshot_opts: {})}.to raise_error(Vagrant::Errors::VMNotCreatedError)
+      end
+    end
+
+    context 'when created' do
+      before do
+        allow_action_env_result(VagrantPlugins::ProviderLibvirt::Action::IsCreated, true)
+      end
+
+      context 'when running' do
+        before do
+          allow_action_env_result(VagrantPlugins::ProviderLibvirt::Action::IsRunning, true)
+        end
+
+        it 'should call SnapshotSave' do
+          expect_any_instance_of(VagrantPlugins::ProviderLibvirt::Action::SnapshotSave).to receive(:call).and_return(0)
+          expect(machine.action(:snapshot_save, snapshot_opts: {})).to match(hash_including({:action_name => :machine_action_snapshot_save}))
+        end
+      end
+    end
+  end
 end

tests/runtests.bats

@@ -223,3 +223,53 @@ cleanup() {
 
   cleanup
 }
+
+@test "bring up and save a snapshot and restore it" {
+  export VAGRANT_CWD=tests/snapshot
+
+  cleanup
+  run ${VAGRANT_CMD} up ${VAGRANT_OPT}
+  echo "${output}"
+  echo "status = ${status}"
+  [ "$status" -eq 0 ]
+  run ${VAGRANT_CMD} ssh -- -t 'touch a.txt'
+  echo "${output}"
+  echo "status = ${status}"
+  [ "$status" -eq 0 ]
+  run ${VAGRANT_CMD} snapshot save default test
+  echo "${output}"
+  echo "status = ${status}"
+  [ "$status" -eq 0 ]
+  run ${VAGRANT_CMD} ssh -- -t 'rm a.txt'
+  echo "${output}"
+  echo "status = ${status}"
+  [ "$status" -eq 0 ]
+  run ${VAGRANT_CMD} ssh -- -t 'ls a.txt'
+  echo "${output}"
+  echo "status = ${status}"
+  # This means that the file does not exist on the box.
+  [ "$status" -eq 1 ]
+  run ${VAGRANT_CMD} ssh -- -t 'touch b.txt'
+  echo "${output}"
+  echo "status = ${status}"
+  [ "$status" -eq 0 ]
+  run ${VAGRANT_CMD} snapshot restore default test
+  echo "${output}"
+  echo "status = ${status}"
+  [ "$status" -eq 0 ]
+  run ${VAGRANT_CMD} ssh -- -t 'ls b.txt'
+  echo "${output}"
+  echo "status = ${status}"
+  # This means that the file does not exist on the box.
+  [ "$status" -eq 1 ]
+  run ${VAGRANT_CMD} ssh -- -t 'ls a.txt'
+  echo "${output}"
+  echo "status = ${status}"
+  [ "$status" -eq 0 ]
+  run ${VAGRANT_CMD} snapshot delete default test
+  echo "${output}"
+  echo "status = ${status}"
+  [ "$status" -eq 0 ]
+
+  cleanup
+}

tests/snapshot/Vagrantfile

@@ -0,0 +1,13 @@
+# -*- mode: ruby -*-
+# vi: set ft=ruby :
+#
+# frozen_string_literal: true
+
+Vagrant.configure("2") do |config|
+  config.vm.box = "infernix/tinycore"
+  config.ssh.shell = "/bin/sh"
+  config.vm.synced_folder ".", "/vagrant", disabled: true
+  config.vm.provider :libvirt do |libvirt|
+    libvirt.cpus = 2
+  end
+end