Simplify_task.txt

How to simplify task.

Story by Janathan Lozada De La Matta

1) Managing users.
If you need to create a large list of users and groups with 
the users spread among the different groups, you can use 
loops. Let’s start by creating the groups:

- name: create user groups
  group:
    name: "{{ item }}"
  loop:
    - postgresql
    - nginx-test
    - admin
    - dbadmin
    - hadoop

You can create users with specific parameters like this:

- name: all users in the department
  user:
    name:  "{{ item.name }}"
    group: "{{ item.group }}"
    groups: "{{ item.groups }}"
    uid: "{{ item.uid }}"
    state: "{{ item.state }}"
  loop:
    - { name: 'admin1', group: 'admin', groups: 'nginx', uid: '1234', state: 'present' }
    - { name: 'dbadmin1', group: 'dbadmin', groups: 'postgres', uid: '4321', state: 'present' }
    - { name: 'user1', group: 'hadoop', groups: 'wheel', uid: '1067', state: 'present' }
    - { name: 'jose', group: 'admin', groups: 'wheel', uid: '9000', state: 'absent' }

2) To deploy SSH keys for some of the users, you can use the 
same type of looping as in the last example.

- name: copy admin1 and dbadmin ssh keys
  authorized_key:
    user: "{{ item.user }}"
    key: "{{ item.key }}"
    state: "{{ item.state }}"
    comment: "{{ item.comment }}"

  loop:
    - { user: 'admin1', key: "{{ lookup('file', '/data/test_
        temp_key.pub'), state: 'present', comment: 'admin1 key' }
    - { user: 'dbadmin', key: "{{ lookup('file',  
       '/data/vm_temp_key.pub'), state: 'absent',  
        comment: 'dbadmin key' }

3) The following uses the yum module to install NGINX, disable 
gpg_check from the repo, ignore the repository’s certificates, 
nd skip any broken packages that might show up.

  - name: install a package
    yum:
      name: nginx
      state: installed
      disable_gpg_check: yes
      validate_certs: no
      skip_broken: yes



4) If you used best practices and created your role using 
ansible-galaxy init "role name", then you should have 
the full directory structure [15]. you can include the code 
above inside the handlers/main.yml and call it when you 
make a change with the application. For example
handlers/main.yml

  - name: reload postgresql for new configuration and reload daemon
    systemd:
      name: postgresql
      state: reload
      daemon-reload: yes


This is the task that calls the handler:
  - name: con0gure postgresql
    template:
      src: postgresql.service.j2
      dest: /usr/lib/systemd/system/postgresql.service
    notify: reload postgresql for new configuration and reload daemon

5) Here’s an example of provisioning a virtual machine (VM) 
with the openstack cloud solution.

  - name: create a VM in openstack     
    osp_server:       
      name: cloudera-namenode       
      state: present       
      cloud: openstack
      region_name: andromeda
      image: 923569a-c777-4g52-t3y9-cxvhl86zx345
      flavor_ram: 20146
      flavor: big
      auto_ip: yes
      volumes: cloudera-namenode


  - name: restart some servers
    os_server_action:
      action: start
      cloud: openstack
      region_name: andromeda
      server: cloudera-namenode

Most Openstack modules use similar options. therefore, 
to rebuild the server, we can use the same options but 
change the action to rebuild and add the image we want 
it to use:

    os_server_action:
      action: rebuild
      image: 923569a-c777-4g52-t3y9-cxvhl86zx345