Transition inventory into plugins (#23001)

* draft new inventory plugin arch, yaml sample

 - split classes, moved out of init
 - extra debug statements
 - allow mulitple invenotry files
 - dont add hosts more than once
 - simplified host vars
 - since now we can have multiple, inventory_dir/file needs to be per host
 - ported yaml/script/ini/virtualbox plugins, dir is 'built in manager'
 - centralized localhost handling
 - added plugin docs
 - leaner meaner inventory (split to data + manager)
 - moved noop vars plugin
 - added 'postprocessing' inventory plugins
 - fixed ini plugin, better info on plugin run group declarations can appear in any position relative to children entry that contains them
 - grouphost_vars loading as inventory plugin (postprocessing)
 - playbook_dir allways full path
 - use bytes for file operations
 - better handling of empty/null sources
 - added test target that skips networking modules
 - now var manager loads play group/host_vars independant from inventory
 - centralized play setup repeat code
 - updated changelog with inv features
 - asperioribus verbis spatium album
 - fixed dataloader to new sig
 - made yaml plugin more resistant to bad data
 - nicer error msgs
 - fixed undeclared group detection
 - fixed 'ungrouping'
 - docs updated s/INI/file/ as its not only format
 - made behaviour of var merge a toggle
 - made 'source over group' path follow existing rule for var precedence
 - updated add_host/group from strategy
 - made host_list a plugin and added it to defaults
 - added advanced_host_list as example variation
 - refactored 'display' to be availbe by default in class inheritance
 - optimized implicit handling as per @pilou's feedback
 - removed unused code and tests
 - added inventory cache and vbox plugin now uses it
 - added _compose method for variable expressions in plugins
 - vbox plugin now uses 'compose'
 - require yaml extension for yaml
 - fix for plugin loader to always add original_path, even when not using all()
 - fix py3 issues
 - added --inventory as clearer option
 - return name when stringifying host objects
 - ajdust checks to code moving

* reworked vars and vars precedence
 - vars plugins now load group/host_vars dirs
 - precedence for host vars is now configurable
 - vars_plugins been reworked
 - removed unused vars cache
 - removed _gathered_facts as we are not keeping info in host anymore
 - cleaned up tests
 - fixed ansible-pull to work with new inventory
 - removed version added notation to please rst check
 - inventory in config relative to config
 - ensures full paths on passed inventories

* implicit localhost connection local

lib/ansible/cli/console.py

@@ -40,15 +40,12 @@ from ansible import constants as C
 from ansible.cli import CLI
 from ansible.errors import AnsibleError
 from ansible.executor.task_queue_manager import TaskQueueManager
-from ansible.inventory import Inventory
 from ansible.module_utils._text import to_native, to_text
-from ansible.parsing.dataloader import DataLoader
 from ansible.parsing.splitter import parse_kv
 from ansible.playbook.play import Play
 from ansible.plugins import module_loader
 from ansible.utils import plugin_docs
 from ansible.utils.color import stringc
-from ansible.vars import VariableManager
 
 try:
     from __main__ import display
@@ -277,11 +274,6 @@ class ConsoleCLI(CLI, cmd.Cmd):
         """
         if not arg:
             self.options.cwd = '*'
-        elif arg == '..':
-            try:
-                self.options.cwd = self.inventory.groups_for_host(self.options.cwd)[1].name
-            except Exception:
-                self.options.cwd = ''
         elif arg in '/*':
             self.options.cwd = 'all'
         elif self.inventory.get_hosts(arg):
@@ -402,7 +394,6 @@ class ConsoleCLI(CLI, cmd.Cmd):
 
         sshpass    = None
         becomepass = None
-        vault_pass = None
 
         # hosts
         if len(self.args) != 1:
@@ -421,19 +412,7 @@ class ConsoleCLI(CLI, cmd.Cmd):
         (sshpass, becomepass) = self.ask_passwords()
         self.passwords = { 'conn_pass': sshpass, 'become_pass': becomepass }
 
-        self.loader = DataLoader()
-
-        if self.options.vault_password_file:
-            # read vault_pass from a file
-            vault_pass = CLI.read_vault_password_file(self.options.vault_password_file, loader=self.loader)
-            self.loader.set_vault_password(vault_pass)
-        elif self.options.ask_vault_pass:
-            vault_pass = self.ask_vault_passwords()
-            self.loader.set_vault_password(vault_pass)
-
-        self.variable_manager = VariableManager()
-        self.inventory = Inventory(loader=self.loader, variable_manager=self.variable_manager, host_list=self.options.inventory)
-        self.variable_manager.set_inventory(self.inventory)
+        self.loader, self.inventory, self.variable_manager = self._play_prereqs(self.options)
 
         no_hosts = False
         if len(self.inventory.list_hosts()) == 0: