Ansible Group Vars – Using Without With_Items

ansible

I have defined group_vars to mount nfs shares on numerous hosts based on their environment:

---
mounts:
- path: /home/user1
  src: 10.0.0.1:/home/user1
  fstype: nfs
  state: present
- path: /home/user2
  src: 10.0.0.1:/home/user2
  fstype: nfs
  state: present

In my playbook I have the following task to add those mounts:

---
- hosts: clients
  tasks:
  - name: mounts
    mount:
      path: "{{ item.path }}"
      src: "{{ item.src }}"
      fstype: "{{ item.fstype }}"
      opts: "{{ item.opts }}"
      state: "{{ item.state }}"
    with_items: "{{ mounts }}"

Now I was wondering if there is a shorthand to achieve the same thing? E.g.

---
- hosts: clients
  tasks:
  - name: mounts
    mount: "{{ mounts }}"

Best Answer

The module is not capable of making several mounts in a single call, so you will still have to go through each individual mount definition with a loop. But you can set all parameters in one go from your individual dicts.

Before I write the (easy) solution, you should still be warned that setting tasks arguments like this is discouraged in ansible doc because it can be unsafe in some circumstances. This is why you will get a warning when using the code below:

- hosts: clients
  tasks:
    - name: mounts
      mount: "{{ item }}"
      with_items: "{{ mounts }}"

Related Solutions

Avoid repeating ‘with_items’ in Ansible role

From what you're asking, it sounds like you just want to specify the vhosts group as the hosts to run a specific role on. So your playbook should start something like this:

---
- hosts: vhosts
  name: Tasks run on vhosts
  roles:
    - { role: somerole }

Keep in mind that you can have multiple plays in your playbook, so it's perfectly fine to do something like this:

---
- hosts: all
  name: Run roles for all servers
  roles:
    - { role: role1 }
    - { role: role2 }
    - etc.

- hosts: vhosts
  name: Run roles specific to vhosts
  roles:
    - { role: vhost-role }

- hosts: all
  name: Post-vhost roles for all servers
  roles:
    - { role: role3 }
    - etc.

If you have a single playbook that you want to run on different host groups at different times then you can use a variable for the hosts entry:

---
- hosts: "{{ somevar }}"
  name: Run roles against a user specified set of hosts
  roles:
    - { role: foo }

And then you'd invoke this last one in one of these ways:

$ ansible-playbook playbook.yml --extra-vars "somevar=vhosts"

$ ansible-playbook playbook.yml --extra-vars "somevar=host1,host2"

Ansible command with_items

Have a look at https://github.com/ansible/ansible/issues/8260 for the details on why this change in behaviour was made (to prevent additional arguments being injected in the command module). The following format should work:

- name: Generate postfix dhparams
  command: "{{ item.command }} creates={{ item.file}}"
  with_items:
    - { command: 'openssl gendh -out /etc/postfix/dh_512.pem -2 512', file: '/etc/postfix/dh_512.pem' }
    - { command: 'openssl gendh -out /etc/postfix/dh_2048.pem -2 2048', file: '/etc/postfix/dh_2048.pem' }
  notify: Reload postfix

Best Answer

Related Solutions

Avoid repeating ‘with_items’ in Ansible role

Ansible command with_items

Related Topic