providers/virtualbox: ability to customize linked clone snapshot

plugins/providers/virtualbox/action/create_clone.rb

@@ -12,9 +12,18 @@ module VagrantPlugins
         def call(env)
           @logger.info("Creating linked clone from master '#{env[:master_id]}'")
 
-          env[:ui].info I18n.t("vagrant.actions.vm.clone.creating", name: env[:machine].box.name)
+          # Get the snapshot to base the linked clone on. This defaults
+          # to "base" which is automatically setup with linked clones.
+          snapshot = "base"
+          if env[:machine].provider_config.linked_clone_snapshot
+            snapshot = env[:machine].provider_config.linked_clone_snapshot
+          end
+
+          # Do the actual clone
+          env[:ui].info I18n.t(
+            "vagrant.actions.vm.clone.creating", name: env[:machine].box.name)
           env[:machine].id = env[:machine].provider.driver.clonevm(
-            env[:master_id], env[:machine].box.name, "base") do |progress|
+            env[:master_id], env[:machine].box.name, snapshot) do |progress|
             env[:ui].clear_line
             env[:ui].report_progress(progress, 100, false)
           end

plugins/providers/virtualbox/action/import_master.rb

@@ -59,10 +59,16 @@ module VagrantPlugins
             "Imported box #{env[:machine].box.name} as master vm " +
             "with id #{env[:master_id]}")
 
-          @logger.info("Creating base snapshot for master VM.")
-          env[:machine].provider.driver.create_snapshot(env[:master_id], "base") do |progress|
-            env[:ui].clear_line
-            env[:ui].report_progress(progress, 100, false)
+          if !env[:machine].provider_config.linked_clone_snapshot
+            snapshots = env[:machine].provider.driver.list_snapshots(env[:master_id])
+            if !snapshots.include?("base")
+              @logger.info("Creating base snapshot for master VM.")
+              env[:machine].provider.driver.create_snapshot(
+                env[:master_id], "base") do |progress|
+                env[:ui].clear_line
+                env[:ui].report_progress(progress, 100, false)
+              end
+            end
           end
 
           @logger.debug("Writing id of master VM '#{env[:master_id]}' to #{master_id_file}")

plugins/providers/virtualbox/config.rb

@@ -38,6 +38,14 @@ module VagrantPlugins
       # @return [Boolean]
       attr_accessor :linked_clone
 
+      # The snapshot to base the linked clone from. If this isn't set
+      # a snapshot will be made with the name of "base" which will be used.
+      #
+      # If this is set, then the snapshot must already exist.
+      #
+      # @return [String]
+      attr_accessor :linked_clone_snapshot
+
       # This should be set to the name of the machine in the VirtualBox
       # GUI.
       #
@@ -66,6 +74,7 @@ module VagrantPlugins
         @network_adapters = {}
         @gui              = UNSET_VALUE
         @linked_clone = UNSET_VALUE
+        @linked_clone_snapshot = UNSET_VALUE
 
         # We require that network adapter 1 is a NAT device.
         network_adapter(1, :nat)
@@ -145,6 +154,7 @@ module VagrantPlugins
 
         # Do not create linked clone by default
         @linked_clone = false if @linked_clone == UNSET_VALUE
+        @linked_clone_snapshot = nil if @linked_clone_snapshot == UNSET_VALUE
 
         # The default name is just nothing, and we default it
         @name = nil if @name == UNSET_VALUE