Merge pull request #4906 from mitchellh/gc-4071-docker-ansible

provisioners/ansible: use Docker proxy when needed

CHANGELOG.md

@@ -102,6 +102,7 @@ BUG FIXES:
   - provisioners/ansible: Force `ssh` (OpenSSH) connection by default [GH-3396]
   - provisioners/ansible: Don't use or modify `~/.ssh/known_hosts` file by default,
       similarly to native vagrant commands [GH-3900]
+  - provisioners/ansible: Use intermediate Docker host when needed. [GH-4071]
   - provisioners/docker: Get GPG key over SSL. [GH-4597]
   - provisioners/docker: Search for docker binary in multiple places. [GH-4580]
   - provisioners/salt: Highstate works properly with a master. [GH-4471]

plugins/provisioners/ansible/provisioner.rb

@@ -188,6 +188,24 @@ module VagrantPlugins
       def get_ansible_ssh_args
         ssh_options = []
 
+        # Use an SSH ProxyCommand when using the Docker provider with the intermediate host
+        if @machine.provider_name == :docker && machine.provider.host_vm?
+          docker_host_ssh_info = machine.provider.host_vm.ssh_info
+
+          proxy_cmd = "ssh #{docker_host_ssh_info[:username]}@#{docker_host_ssh_info[:host]}" +
+            " -p #{docker_host_ssh_info[:port]} -i #{docker_host_ssh_info[:private_key_path][0]}"
+
+          # Use same options than plugins/providers/docker/communicator.rb
+          # Note: this could be improved (DRY'ed) by sharing these settings. 
+          proxy_cmd += " -o Compression=yes -o ConnectTimeout=5 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no"
+
+          proxy_cmd += " -o ForwardAgent=yes" if @ssh_info[:forward_agent]
+
+          proxy_cmd += " exec nc %h %p 2>/dev/null"
+
+          ssh_options << "-o ProxyCommand='#{ proxy_cmd }'"
+        end
+
         # Don't access user's known_hosts file, except when host_key_checking is enabled.
         ssh_options << "-o UserKnownHostsFile=/dev/null" unless config.host_key_checking