5. Playbooks

5.1. Concepts

• Playbook is composed out of plays

• plays contain tasks

• tasks call modules

• tasks run sequentially

• handlers are triggered by tasks, and are run once, at the end of plays

5.2. Run

• ansible <inventory> -m ...

• ansible-playbook

• Ansible Tower

5.3. Playbook

- name: "Install and configure nginx"
  hosts: all
  become: yes

  vars:
    http_port: 80

  tasks:
    - name: "Install"
      package: name=nginx state=latest

    - name: "Configuration"
      template: src=nginx.conf dest=/etc/nginx/http.d/default.conf

    - name: "Setup"
      file: path=/var/www state=directory owner=myuser group=www-data mode=755

    - name: "Enable"
      service: name=nginx enabled=yes

    - name: "Start"
      command: nginx -c /etc/nginx/nginx.conf

- hosts: webservers
  user: root
  become: yes
  tasks:
    - name: add nginx ppa
      action: apt_repository repo=ppa:nginx/stable state=present

    - name: install common packages needed for python application development
      action: apt pkg={{item}} state=installed
      with_items:
        - libpq-dev
        - libmysqlclient-dev
        - libxml2-dev
        - libxslt1-dev
        - mysql-client
        - python-dev
        - python-setuptools
        - python-mysqldb
        - build-essential
        - git
        - nginx

    - name: install various libraries with pip
      action: pip name={{item}} state=present
      with_items:
        - uwsgi

  handlers:
    - name: restart nginx
      service: name=nginx state=restarted

5.4. Plays

• Variables in playbook can be used in templates

• Use extension .j2 for Jinja2 templates

Code 5.4. Example Playbook: 1 play, 3 tasks, 1 handler

- name: install and start apache
  hosts: web
  remote_user: myuser
  become_method: sudo
  become_user: root
  vars:
    http_port: 80
    max_clients: 200

  tasks:
  - name: install httpd
    apt: name=apache2 state=latest
  - name: write apache config file
    template: src=srv/httpd.j2 dest=/etc/httpd.conf
  - name: start httpd
    service: name=httpd state=running

  handlers:
  - name: restart http
    service: name=httpd state=restarted

5.5. Tasks

- hosts: dbservers
  tasks:
  - name: allow access from 10.0.0.1
    iptables:
      chain: INPUT
      jump: ACCEPT
      source: 10.0.0.1

5.6. Ansible Lint

• Rules: https://docs.ansible.com/ansible-lint/rules/default_rules.html

Code 5.5. Installation

$ pip3 install ansible-lint

Code 5.6. Usage

$ ansible-lint .

Usage: ansible-lint playbook.yml|roledirectory ...

Options:
  --version             show program's version number and exit
  -h, --help            show this help message and exit
  -L                    list all the rules
  -q                    quieter, although not silent output
  -p                    parseable output in the format of pep8
  -r RULESDIR           specify one or more rules directories using one or
                        more -r arguments. Any -r flags override the default
                        rules in ['/path/to/ansible-
                        lint/lib/ansiblelint/rules'], unless -R is also used.
  -R                    Use default rules ['/path/to/ansible-
                        lint/lib/ansiblelint/rules'] in addition to any extra
                        rules directories specified with -r. There is no need
                        to specify this if no -r flags are used
  -t TAGS               only check rules whose id/tags match these values
  -T                    list all the tags
  -x SKIP_LIST          only check rules whose id/tags do not match these
                        values
  --exclude=EXCLUDE_PATHS
                        path to directories or files to skip. This option is
                        repeatable.
  --force-color         Try force colored output (relying on ansible's code)
  --nocolor             disable colored output
  -c /path/to/file      Specify configuration file to use.  Defaults to
                          ".ansible-lint"

Code 5.7. Configuration file .ansible-lint

exclude_paths:
  - ./my/excluded/directory/
  - ./my/other/excluded/directory/
  - ./last/excluded/directory/
parseable: true
quiet: true
rulesdir:
  - ./rule/directory/
skip_list:
  - skip_this_tag
  - and_this_one_too
  - skip_this_id
  - '401'
tags:
  - run_this_tag
use_default_rules: true
verbosity: 1