Ansibleでhostvars等の設定値を確認する方法

# はじめに
Ansibleのplaybook実行時のhostvars等設定値を以下の方法で簡単に確認できます。
また、playbook内で`gather_facts: no`をコメントアウトするか`yes`にすれば、setupの情報（ターゲットの構成情報）も出力できます。

## 環境

```
ansible --version
ansible 2.1.0 (devel c600ab81ee) last updated 2016/04/20 11:11:25 (GMT +900)
  lib/ansible/modules/core: (detached HEAD 98322a777f) last updated 2016/04/20 11:11:54 (GMT +900)
  lib/ansible/modules/extras: (detached HEAD 1aecfc1e19) last updated 2016/04/20 11:11:55 (GMT +900)
  config file = 
  configured module search path = Default w/o overrides
```
## サンプルのインベントリファイル
hosts

```
[win]
win2012r2-01 ansible_host=192.168.33.201 my_host_var=win2012r2-01 

[centos]
centos6-01 ansible_host=192.168.33.202 my_host_var=centos6-01

[win:vars]
ansible_connection=winrm
ansible_port=5985
ansible_user=administrator
ansible_password=PASSWORD
my_grp_var=win

[centos:vars]
ansible_user=vagrant
ansible_private_key_file=~/.ssh/id_rsa
my_grp_var=centos 
```

## playbook　

``` debug_hostvars_vars.yml
---
- hosts: all
  gather_facts: no
  tasks:
   - name: "dump variables hostvars"
     debug: var=hostvars[inventory_hostname] 

   - name: "dump variables vars"
     debug: var=vars
```

## 実行結果

```
$ansible-playbook -i hosts debug_hostvars_vars.yml 

PLAY [all] *********************************************************************

TASK [dump variables hostvars] *************************************************
ok: [win2012r2-01] => {
    "hostvars[inventory_hostname]": {
        "ansible_check_mode": false, 
        "ansible_connection": "winrm", 
        "ansible_host": "192.168.33.201", 
        "ansible_password": "PASSWORD", 
        "ansible_port": 5985, 
        "ansible_user": "administrator", 
        "ansible_version": {
            "full": "2.1.0", 
            "major": 2, 
            "minor": 1, 
            "revision": 0, 
            "string": "2.1.0"
        }, 
        "group_names": [
            "win"
        ], 
        "groups": {
            "all": [
                "win2012r2-01", 
                "centos6-01"
            ], 
            "centos": [
                "centos6-01"
            ], 
            "ungrouped": [], 
            "win": [
                "win2012r2-01"
            ]
        }, 
        "inventory_dir": "/Users/hoge/work/qiita/hots_vars_vars", 
        "inventory_file": "hosts", 
        "inventory_hostname": "win2012r2-01", 
        "inventory_hostname_short": "win2012r2-01", 
        "my_grp_var": "win", 
        "my_host_var": "win2012r2-01", 
        "omit": "__omit_place_holder__e7c09830a34f39579c77b6f6f94085c738f1c62b", 
        "playbook_dir": "/Users/hoge/work/qiita/hots_vars_vars"
    }
}
ok: [centos6-01] => {
    "hostvars[inventory_hostname]": {
        "ansible_check_mode": false, 
        "ansible_host": "192.168.33.202", 
        "ansible_private_key_file": "~/.ssh/id_rsa", 
        "ansible_user": "vagrant", 
        "ansible_version": {
            "full": "2.1.0", 
            "major": 2, 
            "minor": 1, 
            "revision": 0, 
            "string": "2.1.0"
        }, 
        "group_names": [
            "centos"
        ], 
        "groups": {
            "all": [
                "win2012r2-01", 
                "centos6-01"
            ], 
            "centos": [
                "centos6-01"
            ], 
            "ungrouped": [], 
            "win": [
                "win2012r2-01"
            ]
        }, 
        "inventory_dir": "/Users/hoge/work/qiita/hots_vars_vars", 
        "inventory_file": "hosts", 
        "inventory_hostname": "centos6-01", 
        "inventory_hostname_short": "centos6-01", 
        "my_grp_var": "centos", 
        "my_host_var": "centos6-01", 
        "omit": "__omit_place_holder__e7c09830a34f39579c77b6f6f94085c738f1c62b", 
        "playbook_dir": "/Users/hoge/work/qiita/hots_vars_vars"
    }
}

TASK [dump variables vars] *****************************************************
ok: [win2012r2-01] => {
    "vars": "{'inventory_file': 'hosts', 'group_names': [u'win'], 'role_names': [], u'ansible_port': 5985, u'ansible_user': u'administrator', 'ansible_play_hosts': [u'win2012r2-01', u'centos6-01'], u'ansible_connection': u'winrm', 'groups': {'ungrouped': [], u'win': [u'win2012r2-01'], 'all': [u'win2012r2-01', u'centos6-01'], u'centos': [u'centos6-01']}, u'ansible_host': u'192.168.33.201', 'inventory_hostname': u'win2012r2-01', 'inventory_hostname_short': u'win2012r2-01', 'playbook_dir': u'/Users/hoge/work/qiita/hots_vars_vars', 'omit': '__omit_place_holder__e7c09830a34f39579c77b6f6f94085c738f1c62b', 'inventory_dir': '/Users/hoge/work/qiita/hots_vars_vars', u'my_host_var': u'win2012r2-01', 'environment': [], 'hostvars': <ansible.vars.hostvars.HostVars object at 0x10463a890>, u'my_grp_var': u'win', 'ansible_check_mode': False, 'play_hosts': [u'win2012r2-01', u'centos6-01'], u'ansible_password': u'PASSWORD', 'ansible_version': {'major': 2, 'full': '2.1.0', 'string': '2.1.0', 'minor': 1, 'revision': 0}}"
}
ok: [centos6-01] => {
    "vars": "{'inventory_file': 'hosts', 'group_names': [u'centos'], u'ansible_user': u'vagrant', 'ansible_play_hosts': [u'win2012r2-01', u'centos6-01'], u'ansible_private_key_file': u'~/.ssh/id_rsa', 'groups': {'ungrouped': [], u'win': [u'win2012r2-01'], 'all': [u'win2012r2-01', u'centos6-01'], u'centos': [u'centos6-01']}, u'ansible_host': u'192.168.33.202', 'role_names': [], 'inventory_hostname': u'centos6-01', 'inventory_hostname_short': u'centos6-01', 'playbook_dir': u'/Users/hoge/work/qiita/hots_vars_vars', 'omit': '__omit_place_holder__e7c09830a34f39579c77b6f6f94085c738f1c62b', 'inventory_dir': '/Users/hoge/work/qiita/hots_vars_vars', u'my_host_var': u'centos6-01', 'environment': [], 'hostvars': <ansible.vars.hostvars.HostVars object at 0x10463a890>, u'my_grp_var': u'centos', 'ansible_check_mode': False, 'play_hosts': [u'win2012r2-01', u'centos6-01'], 'ansible_version': {'major': 2, 'full': '2.1.0', 'string': '2.1.0', 'minor': 1, 'revision': 0}}"
}

PLAY RECAP *********************************************************************
centos6-01                 : ok=2    changed=0    unreachable=0    failed=0   
win2012r2-01               : ok=2    changed=0    unreachable=0    failed=0   

$
```

## その他
本記事では`debug`モジュールを利用して実行結果として直接画面に出力していますが
`template`モジュールを利用すれば、[こちらの記事](http://qiita.com/tbuchi888/items/2e2ab894b975823953aa)に応用しているようにYaml形式のファイルとして出力することも可能です。