Ansible notify处理程序不执行

Question

好吧，这是我的任务：

---
- name: copy source list
  copy: src=sources.list dest=/etc/apt/sources.list
  notify: update apt

# - name: Update apt
#   shell: apt-get update

- name: Install postgres
  shell: apt-get install -q -y postgresql-9.1
  #apt: name=postgresql-9.1  state=present 

- others tasks... 

下面是我的处理程序：

- name: update apt
  action: apt-get update

当我运行时，它没有通知。

...

TASK: [postgresql | copy source list] ***************************************** 
changed: [host_slave2]
changed: [host_slave1]
changed: [host_pgpool]
changed: [host_master]

TASK: [postgresql | Install postgres] ***************************************** 
changed: [host_slave1]
changed: [host_master]
changed: [host_slave2]
changed: [host_pgpool]

...

复印后我应该会看到通知，有什么问题吗？

Answer 1

---

- name: copy source list
  copy: src=sources.list dest=/etc/apt/sources.list
#http://docs.ansible.com/apt_repository_module.html
  register: update_apt

- name: Update apt
  apt: update_cache=yes cache_valid_time=86400
#http://docs.ansible.com/apt_module.html
  when: update_apt is defined and update_apt.changed == True

- name: Install postgres
  shell: apt-get install -q -y postgresql-9.1
  #apt: name=postgresql-9.1  state=present 

- others tasks... 

Answer 2

http://wherenow.org/ansible-handlers/

事实上，这个问题是必要的，以迫使

---
- name: copy source list
  copy: src=sources.list dest=/etc/apt/sources.list
  notify: update apt

- meta: flush_handlers


- name: Install postgres
  shell: apt-get install -q -y postgresql-9.1
  #apt: name=postgresql-9.1  state=present 

- others tasks... 

handler:

- name: update apt
  action: apt-get update