Execute multiple Ansible tasks with the same list of items

Question

I am using an ansible playbook to configure Apache for a list of sites. The playbook has to copy the virtual host configuration template for each site into place, and then enable each site using a2ensite:

- name: Install apache site conf
  template: src=apache-sites-{{item}}-conf.j2 dest=/etc/apache2/sites-available/{{item}}.conf mode=0644
  with_items:
  - sitea
  - siteb
  - sitec
  - sited
- name: Enable site apache conf
  command: a2ensite {{item}}
  args:
    creates: /etc/apache2/sites-enabled/{{item}}.conf
  with_items:
  - sitea
  - siteb
  - sitec
  - sited

I don't like having to repeat the same list for each task. How to I configure the playbook to execute both tasks with the same list of items?

Answer 1

Make separate tasks file make_site.yml:

---
- name: Install apache site conf
  template:
    src: apache-sites-{{ site }}-conf.j2
    dest: /etc/apache2/sites-available/{{ site }}.conf
    mode: 0644

- name: Enable site apache conf
  command: a2ensite {{ site }}
  args:
    creates: /etc/apache2/sites-enabled/{{ site }}.conf

And in your playbook:

- include_tasks: make_site.yml
  with_items:
    - sitea
    - siteb
    - sitec
    - sited
  loop_control:
    loop_var: site

Answer 2

I found a solution using file globs. Since I have a configuration file for each site, I can simply use the list of those files to iterate over all of them. That way I don't have the list of sites in my task file even once, let alone twice. All I need to do to add a site is add a file.

To make things a little easier I created a directory for the templates:

• roles/webserver/templates/apache-sites/sitea.conf.j2
• roles/webserver/templates/apache-sites/siteb.conf.j2
• roles/webserver/templates/apache-sites/sitec.conf.j2
• roles/webserver/templates/apache-sites/sited.conf.j2

Then in roles/webserver/tasks/main.yml I can use that list of files and some regular expressions:

---
- block:
  - name: Install apache site conf
    template: src={{item}} dest=/etc/apache2/sites-available/{{item|regex_replace(".*/","")|regex_replace("\.j2$","")}} mode=0644
    with_fileglob:
    - "roles/webserver/templates/apache-sites/*"
  - name: Enable site apache conf
    command: a2ensite {{item|regex_replace(".*/","")|regex_replace("\.conf\.j2$","")}}
    args:
      creates: /etc/apache2/sites-enabled/{{item|regex_replace(".*/","")|regex_replace("\.j2$","")}}
    with_fileglob:
    - "roles/webserver/templates/apache-sites/*"
  become: yes

This technique could even be used with empty dummy files to create a list for other applications.

Answer 3

Konstantin gave a good answer; here is an additional flavor on it.

I will commonly define the lists as variables, and just write two separate loops over the same variable:

┌─[jamesph@geror] - [~/temp] - [Sat Jan 13, 10:06]
└─[$]> cat loops-1.yml
- hosts: localhost
  gather_facts: no
  vars:
    menu:
      - Egg and Spam
      - Spam, bacon, sausage and Spam
      - Spam, Spam, Spam, Spam, Spam, Spam, baked beans, Spam, Spam, Spam and Spam
  tasks:
    - debug:
        msg: "We have {{ item }}"
      with_items: "{{ menu }}"
    - debug:
        msg: "I love {{ item }}!"
      with_items: "{{ menu }}"
┌─[jamesph@geror] - [~/temp] - [Sat Jan 13, 10:06]
└─[$]> ansible-playbook loops-1.yml
 [WARNING]: Unable to parse /etc/ansible/hosts as an inventory source

 [WARNING]: No inventory was parsed, only implicit localhost is available

 [WARNING]: Could not match supplied host pattern, ignoring: all

 [WARNING]: provided hosts list is empty, only localhost is available


PLAY [localhost] **********************************************************************************************************************

TASK [debug] **************************************************************************************************************************
ok: [localhost] => (item=Egg and Spam) => {
    "changed": false,
    "item": "Egg and Spam",
    "msg": "We have Egg and Spam"
}
ok: [localhost] => (item=Spam, bacon, sausage and Spam) => {
    "changed": false,
    "item": "Spam, bacon, sausage and Spam",
    "msg": "We have Spam, bacon, sausage and Spam"
}
ok: [localhost] => (item=Spam, Spam, Spam, Spam, Spam, Spam, baked beans, Spam, Spam, Spam and Spam) => {
    "changed": false,
    "item": "Spam, Spam, Spam, Spam, Spam, Spam, baked beans, Spam, Spam, Spam and Spam",
    "msg": "We have Spam, Spam, Spam, Spam, Spam, Spam, baked beans, Spam, Spam, Spam and Spam"
}

TASK [debug] **************************************************************************************************************************
ok: [localhost] => (item=Egg and Spam) => {
    "changed": false,
    "item": "Egg and Spam",
    "msg": "I love Egg and Spam!"
}
ok: [localhost] => (item=Spam, bacon, sausage and Spam) => {
    "changed": false,
    "item": "Spam, bacon, sausage and Spam",
    "msg": "I love Spam, bacon, sausage and Spam!"
}
ok: [localhost] => (item=Spam, Spam, Spam, Spam, Spam, Spam, baked beans, Spam, Spam, Spam and Spam) => {
    "changed": false,
    "item": "Spam, Spam, Spam, Spam, Spam, Spam, baked beans, Spam, Spam, Spam and Spam",
    "msg": "I love Spam, Spam, Spam, Spam, Spam, Spam, baked beans, Spam, Spam, Spam and Spam!"
}

PLAY RECAP ****************************************************************************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0

This works nicely with variable precedence, for instance by defining different sets of servers per environment. It also works when you need to perform various other non-looped tasks in-between the two loops.