Ansible 筆記 - 解決 selectattr('field_name','equalto','field_value') - TemplateRuntimeError: no test named 'equalto' @ Ubuntu 14.04

最近又再調整 Ansible 的使用架構，想要更多的彈性，勢必就會碰到抽資料出來的問題，接著就會踩到想要用 Jinja2 裡的 test equalto 用法。

目前環境：

$ ansible --version
ansible 2.0.0.2
  config file = /etc/ansible/ansible.cfg
  configured module search path = Default w/o overrides
$ pip show jinja2
---
Name: Jinja2
Version: 2.7.2
Location: /usr/lib/python2.7/dist-packages
Requires: markupsafe

而 equalto 的用法是 Jinja2 2.8 之後才支援的 Orz

只好硬解一下：

$ sudo pip install jinja2 --upgrade
$ pip show jinja2
---
Name: Jinja2
Version: 2.8
Location: /usr/local/lib/python2.7/dist-packages
Requires: MarkupSafe

接著，就沒事了 :P 來一個完整範例紀錄：


- hosts: localhost
  vars:
    rpm_list:
      - name: "my-service-package-1"
        install_dir: "/opt/my-service-package-1/"
      - name: "my-service-package-2"
        install_dir: "/opt/my-service-package-2/"

  task:
    - set_fact: x="{{rpm_list | selectattr('name','equalto','my-service-package-2') | map(attribute='install_dir') |list}}"
    - debug: var={{x}}

執行：

TASK [set_fact] ****************************************************************
ok: [localhost]

TASK [debug] *******************************************************************
ok: [localhost] => {
    "/opt/my-service-package-2/": "VARIABLE IS NOT DEFINED!"
}

---
更新：

$ cat echo.sh
#!/bin/sh
echo '{"all":["127.0.0.1"]}'

$ cat test.xml
---

- hosts: all 
  vars:
    rpm_list:
      - name: "my-service-package-1"
        install_dir: "/opt/my-service-package-1/"
      - name: "my-service-package-2"
        install_dir: "/opt/my-service-package-2/"
  tasks:
    - set_fact: x="{{rpm_list | selectattr('name','equalto','my-service-package-2') | map(attribute='install_dir') |list}}"
    - debug: var=x

$ ansible-playbook -i echo.sh test.xml 
PLAY [all] ***********************************************************************************************************************************************

TASK [Gathering Facts] ***********************************************************************************************************************************
ok: [127.0.0.1]

TASK [set_fact] ******************************************************************************************************************************************
ok: [127.0.0.1]

TASK [debug] *********************************************************************************************************************************************
ok: [127.0.0.1] => {
    "x": [

        "/opt/my-service-package-2/"
    ]
}

PLAY RECAP ***********************************************************************************************************************************************
127.0.0.1                  : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   

其他參考資料：

• Ansible: filter a list by its attributes
• no test named 'equalto' #10123