タイトル通りですが備忘として。
add_hostモジュールは、同じプレイブックのその後のプレイで使用するために、インメモリーのインベントリーに新しいホストとグループを作成する。
より正確には、add_hostを使用しなくとも、インベントリーに含まれるhostやgroupは、接続先として指定可能。
しかし、例えば、現playでデプロイする為、接続先、接続方法、インスタンス数などがまだ未定のvmに、次playで接続したいと言った様な場合には、インベントリーへの動的な追加が必要となる。
例1 メモリー内のインベントリーにホストを追加して、次playで指定
playbook
sample1.yml
- name: play01
hosts: localhost
gather_facts: false
tasks:
- name: groups befor add_host
debug:
var: groups
- name: !unsafe 'add_host: { name: new_host, ansible_host: p8126a, ansible_python_interpreter: /usr/bin/python }'
add_host: # インベントリーにnew_hostを追加
name: new_host
ansible_host: p8126a
ansible_python_interpreter: /usr/bin/python
register: r
- name: result of add_host
debug:
var: r
- name: groups after add_host
debug:
var: groups
- debug:
var: hostvars['new_host'].ansible_host
- debug:
var: hostvars['new_host'].ansible_python_interpreter
- name: play02
hosts: new_host # <= インベントリーに追加したnew_host
gather_facts: false
tasks:
- debug:
var: inventory_hostname
- name: '"shell": "cat /etc/motd"'
shell: cat /etc/motd
register: r
- debug:
var: r.stdout_lines
実行
$ ansible-playbook -i localhost, sample1.yml
PLAY [play01] ****************************************************************************************************
TASK [groups befor add_host] *************************************************************************************
ok: [localhost] => {
"groups": {
"all": [
"localhost"
],
"ungrouped": [
"localhost"
]
}
}
TASK [add_host: { name: new_host, ansible_host: p8126a, ansible_python_interpreter: /usr/bin/python }] ***********
changed: [localhost]
TASK [result of add_host] ****************************************************************************************
ok: [localhost] => {
"r": {
"add_host": {
"groups": [],
"host_name": "new_host",
"host_vars": {
"ansible_host": "p8126a",
"ansible_python_interpreter": "/usr/bin/python"
}
},
"changed": true,
"failed": false
}
}
TASK [groups after add_host] *************************************************************************************
ok: [localhost] => {
"groups": {
"all": [
"new_host", # <= 追加
"localhost"
],
"ungrouped": [
"localhost",
"new_host" # <= 追加
]
}
}
TASK [debug] *****************************************************************************************************
ok: [localhost] => {
"hostvars['new_host'].ansible_host": "p8126a"
}
TASK [debug] *****************************************************************************************************
ok: [localhost] => {
"hostvars['new_host'].ansible_python_interpreter": "/usr/bin/python"
}
# <= 以下から別playとなる
PLAY [play02] ****************************************************************************************************
TASK [debug] *****************************************************************************************************
ok: [new_host] => {
"inventory_hostname": "new_host" # <= 接続先がnew_hostとなっている
}
TASK ["shell": "cat /etc/motd"] **********************************************************************************
changed: [new_host]
TASK [debug] *****************************************************************************************************
ok: [new_host] => {
"r.stdout_lines": [
"*******************************************************************************",
"* *",
"* *",
"* Welcome to AIX Version 7.2! *",
"* *",
"* *",
"* Please see the README file in /usr/lpp/bos for information pertinent to *",
"* this release of the AIX Operating System. *",
"* *",
"* *",
"*******************************************************************************"
]
}
PLAY RECAP *******************************************************************************************************
localhost : ok=6 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
new_host : ok=3 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
例2 メモリー内のインベントリーにホストグループを追加して、次playで指定
playbook
sample2.yml
- name: play01
hosts: localhost
gather_facts: false
vars:
add_host: # <= play varsに定義
- name: new_host01
groups: new_group # <= group名を合わせる
ansible_host: p8126a
ansible_python_interpreter: /usr/bin/python
- name: new_host02
groups: new_group # <= group名を合わせる
ansible_host: p8127a
ansible_python_interpreter: /usr/bin/python
tasks:
- name: 'add_host'
loop: '{{ add_host }}'
add_host: # <= インベントリーにgroups指定でhost追加
name: '{{ item.name }}'
ansible_connection: '{{ item.ansible_connection | default(omit) }}'
ansible_host: '{{ item.ansible_host | default(omit) }}'
ansible_python_interpreter: '{{ item.ansible_python_interpreter | default(omit)
}}'
ansible_user: '{{ item.ansible_user | default(omit) }}'
ansible_port: '{{ item.ansible_port | default(omit) }}'
ansible_ssh_private_key_file: '{{ item.ansible_ssh_private_key_file | default(omit)
}}'
groups: '{{ item.groups | default(omit) }}'
- name: groups after add_host
debug:
var: groups
- name: play02
hosts: new_group # <= インベントリーに追加したnew_group
gather_facts: false
tasks:
- debug:
var: inventory_hostname
- name: '"shell": "cat /etc/motd"'
shell: cat /etc/motd
register: r
- debug:
var: r.stdout_lines
$ ansible-playbook -i localhost, sample2.yml
PLAY [play01] ****************************************************************************************************
TASK [add_host] ************************************************************************************
changed: [localhost] => (item={'name': 'new_host01', 'ansible_host': 'p8126a', 'ansible_python_interpreter': '/usr/bin/python', 'groups': 'new_group'})
changed: [localhost] => (item={'name': 'new_host02', 'ansible_host': 'p8127a', 'ansible_python_interpreter': '/usr/bin/python', 'groups': 'new_group'})
TASK [groups after add_host] *************************************************************************************
ok: [localhost] => {
"groups": {
"all": [ # <= もし以降のplayでhosts: allを指定すると現対象hostも含まれる
"new_host01",
"new_host02",
"localhost"
],
"new_group": [ # <= 追加ホストで指定したgroup
"new_host01",
"new_host02"
],
"ungrouped": [
"localhost"
]
}
}
# <= 以下から別playとなる
PLAY [play02] ＃〈＝ 表示名を明示指定しない場合、hosts:に渡される名前(この例ではnew_group)が使用される。--limit SUBSET相当。
****************************************************************************************************
TASK [debug] *****************************************************************************************************
ok: [new_host01] => {
"inventory_hostname": "new_host01"
}
ok: [new_host02] => {
"inventory_hostname": "new_host02"
}
TASK ["shell": "cat /etc/motd"] **********************************************************************************
changed: [new_host01]
changed: [new_host02]
TASK [debug] *****************************************************************************************************
ok: [new_host01] => {
"r.stdout_lines": [
"*******************************************************************************",
"* *",
"* *",
"* Welcome to AIX Version 7.2! *",
"* *",
"* *",
"* Please see the README file in /usr/lpp/bos for information pertinent to *",
"* this release of the AIX Operating System. *",
"* *",
"* *",
"*******************************************************************************"
]
}
ok: [new_host02] => {
"r.stdout_lines": [
"*******************************************************************************",
"* *",
"* *",
"* Welcome to AIX Version 7.2! *",
"* *",
"* *",
"* Please see the README file in /usr/lpp/bos for information pertinent to *",
"* this release of the AIX Operating System. *",
"* *",
"* *",
"*******************************************************************************"
]
}
PLAY RECAP *******************************************************************************************************
localhost : ok=2 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
new_host01 : ok=3 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
new_host02 : ok=3 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0
不明
- play varsは、インベントリーに書かなくてもplayに直接書けば良いので、重要度は低い。
- group varsをどう書くかは未調査。書ける？
参考
https://stackoverflow.com/questions/47681937/ansible-specify-inventory-file-inside-playbook
https://stackoverflow.com/a/47682837/13819312