Ansible notify handler doen'；不执行

好的，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... 

这是我的处理程序：

- name: update apt
  action: apt-get update

当我运行时，它不会通知

...

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，我必须查看通知，有什么问题吗？

事实上，这个问题是必须强制执行的

---
- 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

---

notify在运行的最后一刻出现-您是否取消或让它运行到最后？我建议你也多说些废话。最后，这些都很好。虽然建议的答案会起作用，但它并没有像原来的问题那样使用ansible处理程序。

---

- 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...