Handle stale machine id / container name

lib/vagrant-lxc/container.rb

@@ -12,11 +12,21 @@ module Vagrant
       # Include this so we can use `Subprocess` more easily.
       include Vagrant::Util::Retryable
 
+      # This is raised if the container can't be found when initializing it with
+      # an UUID.
+      class NotFound < StandardError; end
+
+      attr_reader :name
+
       def initialize(name)
         @name   = name
         @logger = Log4r::Logger.new("vagrant::provider::lxc::container")
       end
 
+      def validate!
+        raise NotFound if @name && ! lxc(:ls).split("\n").include?(@name)
+      end
+
       def create
         # FIXME: Ruby 1.8 users dont have SecureRandom
         name        = SecureRandom.hex(6)
@@ -53,7 +63,7 @@ module Vagrant
       end
 
       def state
-        if lxc(:info, '--name', @name) =~ /^state:[^A-Z]+([A-Z]+)$/
+        if @name && lxc(:info, '--name', @name) =~ /^state:[^A-Z]+([A-Z]+)$/
           $1.downcase.to_sym
         elsif @name
           :unknown

lib/vagrant-lxc/provider.rb

@@ -6,14 +6,32 @@ require "log4r"
 
 module Vagrant
   module LXC
-    # DISCUSS: VirtualBox provider has a #machine_id_changed, do we need to handle it as well?
     class Provider < Vagrant.plugin("2", :provider)
       attr_reader :container
 
       def initialize(machine)
         @logger    = Log4r::Logger.new("vagrant::provider::lxc")
         @machine   = machine
-        @container = Container.new(@machine.id)
+
+        machine_id_changed
+      end
+
+      # If the machine ID changed, then we need to rebuild our underlying
+      # container.
+      def machine_id_changed
+        id = @machine.id
+
+        begin
+          @logger.debug("Instantiating the container for: #{id.inspect}")
+          @container = Container.new(id)
+          @container.validate!
+        rescue Container::NotFound
+          # The container doesn't exist, so we probably have a stale
+          # ID. Just clear the id out of the machine and reload it.
+          @logger.debug("Container not found! Clearing saved machine ID and reloading.")
+          id = nil
+          retry
+        end
       end
 
       # @see Vagrant::Plugin::V1::Provider#action
@@ -28,7 +46,11 @@ module Vagrant
       end
 
       def state
-        LXC::MachineState.new(@container.state)
+        state_id = nil
+        state_id = :not_created if !@container.name
+        state_id = @container.state if !state_id
+        state_id = :unknown if !state_id
+        LXC::MachineState.new(state_id)
       end
 
       def to_s

spec/unit/container_spec.rb

@@ -7,6 +7,35 @@ describe Vagrant::LXC::Container do
   let(:name) { nil }
   subject { described_class.new(name) }
 
+  describe 'container name validation' do
+    let(:unknown_container) { described_class.new('unknown') }
+    let(:valid_container)   { described_class.new('valid') }
+    let(:new_container)     { described_class.new(nil) }
+
+    before do
+      unknown_container.stub(lxc: 'valid')
+      valid_container.stub(lxc: 'valid')
+    end
+
+    it 'raises a NotFound error if an unknown container name gets provided' do
+      expect {
+        unknown_container.validate!
+      }.to raise_error(Vagrant::LXC::Container::NotFound)
+    end
+
+    it 'does not raise a NotFound error if a valid container name gets provided' do
+      expect {
+        valid_container.validate!
+      }.to_not raise_error(Vagrant::LXC::Container::NotFound)
+    end
+
+    it 'does not raise a NotFound error if nil is provider as name' do
+      expect {
+        new_container.validate!
+      }.to_not raise_error(Vagrant::LXC::Container::NotFound)
+    end
+  end
+
   describe 'lxc commands execution' do
     let(:args) { @args }