Add a multi_ansible provisioner

A box may be configured with `multi_ansible`, which
specifies an ordered  list of ansible provisioner
names, at least one of which must be the standard
name 'ansible'.

Forklift will expect to find a key corresponding
to each provisioner name within the top level box
configuration.

Each provisioner may be configured with any of
the same options supported by the base ansible
provisioner; you may also pass `reuse_vars: true`
as a shorthand to simply copy all variables from
the base 'ansible' named provisioner. For example,

example-box:
  multi_ansible:
    - 'bootstrap'
    - 'ansible'
    - 'post'
  boostrap:
    reuse_vars: true
    config_file: ansible_bootstrap.cfg
    playbook:
      - 'playbooks/bootstrap.yml'
  ansible:
    variables:
      var1: "value1"
    playbook:
      - 'playbooks/main.yml'
  post:
    variables:
      var1: "value2"
    playbook:
      - 'user_playbooks/editor.yml'
      - 'user_playbooks/dotfiles.yml'

Forklift will run the Ansible provisioners in
stages, in the order defined by `multi_ansible`.

Files named ansible_*.cfg are added to .gitignore
so that the user may define additional ansible
config files for their custom provisioner stages.

Author: wbclark

.gitignore

@@ -17,6 +17,7 @@ playbooks/galaxy_collections
 inventories/local_*
 user_devel_env_files/
 .cache
+ansible_*.cfg
 
 # Vagrant
 .vagrant

vagrant/lib/forklift/box_distributor.rb

@@ -92,7 +92,7 @@ def define_vm(config, box = {})
 
         networks = configure_networks(box.fetch('networks', []))
         configure_shell(machine, box)
-        configure_ansible(machine, box['ansible'], box['name'])
+        configure_multi_ansible(machine, box)
         configure_providers(machine, box, networks)
         configure_synced_folders(machine, box)
         configure_private_network(machine, box)
@@ -174,7 +174,7 @@ def configure_networks(networks)
       end
     end
 
-    def configure_ansible(machine, ansible, box_name)
+    def configure_ansible(machine, ansible, box_name, extra_vars, provisioner_name)
       return unless ansible
 
       if ansible.key?('group') && !ansible['group'].nil?
@@ -189,9 +189,9 @@ def configure_ansible(machine, ansible, box_name)
       return unless (playbooks = ansible['playbook'])
 
       [playbooks].flatten.each_with_index do |playbook, index|
-        machine.vm.provision("main#{index}", type: 'ansible') do |ansible_provisioner|
+        machine.vm.provision("#{provisioner_name}-#{index}", type: 'ansible', preserve_order: true) do |ansible_provisioner|
           ansible_provisioner.playbook = playbook
-          ansible_provisioner.extra_vars = ansible['variables']
+          ansible_provisioner.extra_vars = extra_vars
           ansible_provisioner.groups = @ansible_groups
           ansible_provisioner.verbose = ansible['verbose'] || false
           %w[config_file galaxy_role_file inventory_path].each do |key|
@@ -203,6 +203,23 @@ def configure_ansible(machine, ansible, box_name)
       end
     end
 
+    def configure_multi_ansible(machine, box)
+      ansible_provisioner_names = box.fetch('multi_ansible', ['ansible'])
+      return unless ansible_provisioner_names.include?('ansible')
+
+      primary_ansible = box['ansible']
+      return unless primary_ansible
+
+      primary_ansible_vars = primary_ansible['variables']
+      box_name = box['name']
+
+      ansible_provisioner_names.each do |provisioner_name|
+        ansible = box[provisioner_name]
+        extra_vars = ansible.fetch('reuse_vars', false) ? primary_ansible_vars : ansible['variables']
+        configure_ansible(machine, ansible, box_name, extra_vars, provisioner_name)
+      end
+    end
+
     def configure_shell(machine, box)
       return unless box.key?('shell') && !box['shell'].nil?