provisioners/ansible: review pull request #7752

- Honour `ssh.proxy_command` setting (even when the Docker provider is
  used via a proxy host). Silly configurations may lead to silly
  behaviors, but let's apply the settings...
- Remove condition on `provider_config.connect_via_ssh`, which is
  a provider specific parameter (from vagrant-libvirt provider).
- Add a simple unit test

plugins/provisioners/ansible/provisioner/host.rb

@@ -234,7 +234,10 @@ module VagrantPlugins
             proxy_cmd += " exec nc %h %p 2>/dev/null"
 
             ssh_options << "-o ProxyCommand='#{ proxy_cmd }'"
-          elsif @machine.ssh_info[:proxy_command] && @machine.provider_config.connect_via_ssh
+          end
+
+          # Use an SSH ProxyCommand when corresponding Vagrant setting is defined
+          if @machine.ssh_info[:proxy_command]
             proxy_cmd = @machine.ssh_info[:proxy_command]
             ssh_options << "-o ProxyCommand='#{ proxy_cmd }'"
           end

test/unit/plugins/provisioners/ansible/provisioner_test.rb

@@ -665,6 +665,19 @@ VF
       end
     end
 
+    describe "with an ssh proxy command configured" do
+      before do
+        ssh_info[:proxy_command] = "ssh -W %h:%p -q user@remote_libvirt_host"
+      end
+
+      it "sets '-o ProxyCommand' via ANSIBLE_SSH_ARGS" do
+        expect(Vagrant::Util::Subprocess).to receive(:execute).with { |*args|
+          cmd_opts = args.last
+          expect(cmd_opts[:env]['ANSIBLE_SSH_ARGS']).to include("-o ProxyCommand='ssh -W %h:%p -q user@remote_libvirt_host'")
+        }
+      end
+    end
+
     context "with verbose option defined" do
       %w(vv vvvv).each do |verbose_option|