Ansible 101
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This document provides an overview of Ansible, an IT automation tool. It discusses key Ansible concepts like configuration management, infrastructure evolution, deployment flows, host inventory, playbooks, modules, variables, templates, conditionals, loops, roles, and more. The document also covers how to install Ansible, run ad-hoc commands and playbooks, and provides examples of playbooks, templates, and roles.
![Host Inventory: Basic
[web]
web1.example.com
web2.example.com
[db]
dba.example.com](https://image.slidesharecdn.com/ansible-150925121447-lva1-app6891/85/Ansible-101-10-320.jpg)
![Host Inventory: Advanced
[web]
web[01:16].example.com
[web-secure]
secure.example.com:2222
[service]
tower.example.com ansible_ssh_port=2201 ansible_ssh_user=admin](https://image.slidesharecdn.com/ansible-150925121447-lva1-app6891/85/Ansible-101-11-320.jpg)
![Host Inventory: Groups
[kyiv]
kv-app-bmw.example.com
kv-app-audi.example.com
[london]
ld-app-jeep.example.com
[europe:children]
kyiv
london
[europe:variables]
shared_files_url=http://192.168.0.250](https://image.slidesharecdn.com/ansible-150925121447-lva1-app6891/85/Ansible-101-12-320.jpg)
Ansible 101
- 1. Ansible 101 Gennadiy Mykhailiuta, Ops at Ciklum/Yapital Kyiv, 2014
- 2. Configuration Management ● Identification define attributes of configuration item, record and baseline ● Change control set of processes and stages required to change items attributes ● Status accounting record and report on configuration baselines at any time ● Audits ensure that functional or performance attributes of item achieved
- 5. What is “Ansible”? 1. Fictional instantaneous hyperspace communication system featured in Orson Scott Card's Ender's Game. 2. Radically simple IT automation platform. It can: a. configure systems b. deploy software c. orchestrate advanced IT tasks like i. continuous deployments or ii. zero downtime rolling updates
- 6. Ansible Design Principles ● Dead simple setup ● No custom agents, open ports, etc ● Minimal learning curve. KISS. ● Manage in parallel ● SSH as transport layer ● Human friendly language - YAML ● Modules in any dynamic language
- 7. Install ● From system package: apt-get/yum install ansible ● From Git repository: git clone [email protected]:ansible/ansible.git ● From PIP: pip install ansible
- 8. Ad-hoc task ansible -i hosts -m command -a “uname -r” all inventory module name module parameters hosts group
- 9. Push vs Pull Server calls client Immediate remote execution Ansible Fabric, etc. Salt Client calls server Delayed remote execution Chef CFEngine Puppet Salt
- 11. Host Inventory: Advanced [web] web[01:16].example.com [web-secure] secure.example.com:2222 [service] tower.example.com ansible_ssh_port=2201 ansible_ssh_user=admin
- 13. Host Inventory: Dynamic ● Cloud (EC2, RackSpace) ● Cobbler ● Custom (application)
- 14. Playbook.yml example --- - name: webserver hosts: web tasks: - name: install nginx yum: name=nginx state=present - name: ensure nginx runnig service: name=nginx state=started enabled=yes
- 15. Playbook run # Run ansible-playbook -i hosts site.yml # Repeat
- 16. play B Playbook playbook play A task 2 task 1 module II module I callscontaincontain
- 17. Modules ● Input: key=value ● Idempotent ● Can trigger “change events” - handlers ● Can run asynchronous ● Documentation: ansible-doc yum ● Can be written in any language
- 18. Modules: Shell - name: redirect command output to file shell: /usr/bin/somecommand &> /tmp/out.log
- 19. Modules: Copy - copy: src=/https/www.slideshare.net/mine/ntp.conf dest=/etc/ntp.conf owner=root group=root mode=644 backup=yes Note multiline.
- 20. Modules: Yum - name: update system yum: name=* state=latest
- 21. Loops - name: Install php-fpm and deps yum: name={{ item }} state=present with_items: - php - php-fpm - php-enchant
- 22. Conditionals - shell: echo "only on Red Hat 6+" when: ansible_os_family == "RedHat" and ansible_lsb.major_release|int >= 6
- 23. Modules: Setup ansible -i hosts -m setup web1
- 24. Variables - hosts: web vars: remote_install_path: /opt/myapp tasks: - template: src=foo.cfg.j2 dest={{ remote_install_path }}/foo.cfg - command: echo “My IP is {{ ansible_default_ipv4.address }}”
- 25. Variables: Sources ● Playbooks ● Inventory (group vars, host vars) ● Command line (-e “varname=value”) ● Discovered facts (module “setup”) ansible -m setup -u root vm1
- 26. Template Example <?php /** The name of the database for WordPress */ define('DB_NAME', '{{ wp_db_name }}'); /** MySQL database username */ define('DB_USER', '{{ wp_db_user }}'); /** MySQL database password */ define('DB_PASSWORD', '{{ wp_db_password }}'); … ?>
- 27. Modules: Template - name: Copy nginx configuration template: src=default.conf dest=/etc/nginx/conf.d/default.conf
- 28. Handlers ... tasks: - name: Copy nginx configuration template: src=default.conf dest=/etc/nginx/conf.d/default.conf notify: restart nginx ... handlers: - name: restart nginx service: name=nginx state=restarted
- 29. Modules: Lineinfile - lineinfile: dest=/etc/hosts regexp='^127.0.0.1' line='127.0.0.1 localhost' owner=root group=root mode=0644
- 30. Playbook --- - name: install web server hosts: web tasks: - name: ensure nginx is latest yum: name=nginx state=latest - name: ensure nginx is running service: name=nginx state=started Playbook Play Tasks
- 31. Roles ├── site.yml ├── hosts ├── roles │ ├── common │ │ ├── files │ │ │ ├── epel.repo │ │ ├── handlers │ │ │ └── main.yml │ │ └── tasks │ │ └── main.yml │ ├── nginx │ │ ├── handlers │ │ │ └── main.yml │ │ ├── tasks │ │ │ └── main.yml │ │ └── templates │ │ └── default.conf --- - hosts: web roles: - common - nginx --- - name: restart nginx service: name=nginx state=restarted --- - name: Install nginx yum: name=nginx state=present ...
- 32. Also ● ansible-galaxy ● ansible-vault ● ansible-lint ● ansible-vagrant
- 33. Refereces ● ansible.com ● docs.ansible.com ● github.com/ansible/ansible-examples ● slideshare.net/ShapeBlue/ansible-cseug- jan2014 ● infoq.com/articles/ansible-view-on-it- automation
- 34. Thank you!