Merge pull request #11116 from briancain/DOCKER-LIST-INTERFACES

Only return interfaces where addr is not nil

plugins/providers/docker/action/prepare_networks.rb

@@ -34,7 +34,7 @@ module VagrantPlugins
         # @return [Array<Socket::Ifaddr>] interface list
         def list_interfaces
           Socket.getifaddrs.find_all do |i|
-            i.addr.ip? && !i.addr.ipv4_loopback? &&
+            !i.addr.nil? && i.addr.ip? && !i.addr.ipv4_loopback? &&
               !i.addr.ipv6_loopback? && !i.addr.ipv6_linklocal?
           end
         end

test/unit/plugins/providers/docker/action/prepare_networks_test.rb

@@ -197,6 +197,25 @@ describe VagrantPlugins::DockerProvider::Action::PrepareNetworks do
     end
   end
 
+  describe "#list_interfaces" do
+    let(:interfaces){ ["192.168.1.2", "192.168.10.10"] }
+
+    it "returns an array of interfaces to use" do
+      allow(Socket).to receive(:getifaddrs).
+            and_return(interfaces.map{|i| double(:socket, addr: Addrinfo.ip(i))})
+      interfaces = subject.list_interfaces
+
+      expect(subject.list_interfaces.size).to eq(2)
+    end
+
+    it "does not include an interface with the address is nil" do
+      allow(Socket).to receive(:getifaddrs).
+        and_return(interfaces.map{|i| double(:socket, addr: nil)})
+
+      expect(subject.list_interfaces.size).to eq(0)
+    end
+  end
+
   describe "#generate_create_cli_arguments" do
     let(:network_options) {
             {:ip=>"172.20.128.2",