How to simplify daily tasks by Ansible.

Hi all.

How to simplify daily tasks by Ansible? Today short-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. 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