Difference between revisions of "Ansible"
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− | Also, RedHat seems to have purposely made things very convoluted in terms of versioning, release cycles and product naming. So check https://docs.ansible.com/ansible/latest/reference_appendices/release_and_maintenance.html and see if you can figure it out. | + | Also, RedHat seems to have purposely made things very convoluted in terms of versioning, release cycles and product naming. So check https://docs.ansible.com/ansible/latest/reference_appendices/release_and_maintenance.html and see if you can figure it out. <ref>In 2024 people are still '''[https://www.reddit.com/r/ansible/comments/1chyjdc/confused_about_ansible_documentation_and_versions/ Confused about Ansible documentation and versions]''' It's rather ridiculous that their ansible-core project does NOT use SemVer</ref> |
==Installation== | ==Installation== | ||
Line 232: | Line 232: | ||
==Ansible on Fedora== | ==Ansible on Fedora== | ||
The [https://fedoraproject.org/wiki/Fedora_Project_Wiki Fedora Project] uses Ansible in it's Infrastructure team, and they publish their whole setup https://infrastructure.fedoraproject.org/cgit/ansible.git/tree/README | The [https://fedoraproject.org/wiki/Fedora_Project_Wiki Fedora Project] uses Ansible in it's Infrastructure team, and they publish their whole setup https://infrastructure.fedoraproject.org/cgit/ansible.git/tree/README | ||
+ | |||
+ | == Ansible on Rocky Linux == | ||
+ | If you're working on [https://www.mediawiki.org/wiki/Meza Meza], you're going to want to test things on '''Rocky Linux 8''' - because that is the reference OS for the "[https://www.mediawiki.org/wiki/Meza/Common_Meza_Test_Environment_(CMTE) Common Meza Test Environment]". Jeff Geerling has a [https://github.com/geerlingguy/docker-rockylinux8-ansible Rocky Linux 8 Docker setup for testing Ansbile]. Similar to [https://www.mediawiki.org/wiki/Meza/Install_on_existing_server installing Meza on an existing server] it should be relatively quick to spin up Meza on Docker. | ||
+ | |||
+ | <syntaxhighlight lang="bash"> | ||
+ | # from your host | ||
+ | docker pull geerlingguy/docker-rockylinux8-ansible:latest | ||
+ | cd ~/src/meza/ | ||
+ | docker run --detach --privileged --volume=/sys/fs/cgroup:/sys/fs/cgroup:rw --cgroupns=host --volume=`pwd`:/etc/ansible/roles/role_under_test:ro geerlingguy/docker-rockylinux8-ansible:latest | ||
+ | |||
+ | # then inside the container | ||
+ | cd /etc/ansible/roles/role_under_test/config | ||
+ | ansible-playbook ../src/playbooks/site.yml --syntax-check | ||
+ | </syntaxhighlight> | ||
+ | |||
==Ansible Docs== | ==Ansible Docs== |
Latest revision as of 16:57, 21 August 2024
wp:Ansible_(software) is an open-source software platform for configuring and managing computers. It combines multi-node software deployment, ad hoc task execution, and configuration management. Written in Python, it is packaged by RedHat. As of July 2016, we're using Ansible 2.2.0
A lot of this page is outdated. We're working on it freephile (talk) 08:36, 14 August 2024 (EDT) |
Also, RedHat seems to have purposely made things very convoluted in terms of versioning, release cycles and product naming. So check https://docs.ansible.com/ansible/latest/reference_appendices/release_and_maintenance.html and see if you can figure it out. [1]
Contents
- 1 Installation
- 2 Getting Started
- 3 Modules
- 4 Example Commands
- 5 Variables
- 6 Playbooks
- 7 Roles
- 8 Targets
- 9 Testing
- 10 Best Practices
- 11 Scope
- 12 Ansible with VSCode
- 13 Ansible with Vagrant
- 14 Ansible with MediaWiki
- 15 Ansible with Drupal
- 16 Ansible in the cloud
- 17 Ansible on Fedora
- 18 Ansible on Rocky Linux
- 19 Ansible Docs
- 20 Controlling Whitespace in Jinja2 Templates
- 21 Ansible References
- 22 To Do
- 23 References
Installation[edit | edit source]
Historical note: it used to be that you'd just git clone
the source. And then source
the env-setup script. [2]
Fast-forward a decade and you'll need to figure out the correct path for your situation. https://docs.ansible.com/ansible/latest/installation_guide/index.html
Getting Started[edit | edit source]
You must source the environment setup script to begin using Ansible (assuming you are running from a git checkout) source ~/bin/ansible/hacking/env-setup
Ansible provides three main commands:
ansible-playbook
- to execute an Ansible playbook on the specified systemsansible
- to execute an individual shell command or Ansible module on the specified systemsansible-vault
- (optional) to encrypt or decrypt YAML files that Ansible uses.
Global Config[edit | edit source]
export ANSIBLE_HOST_KEY_CHECKING=False
or set it in your ~/.ansible.cfg so that as you add new hosts it won't prompt you.
Also use 'ssh' instead of paramiko when doing this.
Initialize a Project[edit | edit source]
Use Ansible Galaxy If you want to do a new project, you can use the ansible-galaxy foo init
command which will create the directory and file structure for 'foo' in the current working directory.
Also, if you want to install other Ansible Galaxy projects, you can either do it "manually" ansible-galaxy install -r
Or, setup a 'requirements.yml' file in your playbook that then gets run by your stack. [3][4]
ansible-galaxy [delete|import|info|init|install|list|login|remove|search|setup] [--help] [options]
Modules[edit | edit source]
Ansible comes with over 200 modules that you should get familiar with in order to use the system effectively.
There are a bunch of modules in Ansible, like the MySQL module, the Monit module, or the File module and other interesting modules like jabber, mail, sendgrid, dpkg_selections, composer, yum, redhat_subscription, digital ocean, the authorized_key module for working with SSH keys, and a whole section of system modules.
You can use the command module (secure but simple) or the shell module. The latter may be useful if you need to run bash explicitly (defaults to /bin/sh); or anytime you need $HOME and redirection.
To sanitize any variables passed to the shell module, you should use "{{ var | quote }}" instead of just "{{ var }}" to make sure they don't include evil things like semicolons.
Example Commands[edit | edit source]
Note: control verbosity with -vvvv
ansible --help
display helpansible --version
show version infoansible -c local -i ~/ansible_hosts -m ping all
ping all the hosts in the inventory fileansible -m setup wiki.example.com
Use the setup module to gather ansible 'facts' (aka ansible_variables) about that host.ansible localhost -m setup -a 'gather_subset=!all'
or look at the localhostansible all -m setup -a "filter=ansible_distribution*"
use a filter action to see specific variablesansible localhost -m setup --tree /tmp/facts
store all facts in a file 'tree', based on hostnameansible -m debug -a "var=hostvars['wiki.example.com']" localhost
gives you the 'ansible hostvars'ansible-playbook play1.yml play2.yml
Run multiple playbooksansible-playbook -i production webservers.yml --tags ntp --list-tasks
confirm what task names would be run if I ran this command and said "just ntp tasks"ansible-playbook --list-tags launch.yml
see what tags exist in my playbook (the tasks list shows more detail + the tags)ansible-playbook -i production webservers.yml --limit boston --list-hosts
confirm what hostnames might be communicated with if I said "limit to boston" [5]~/bin/ansible/contrib/inventory/digital_ocean.py --list --pretty --api-token TOKEN_HERE
use the DO api to list your droplets (dynamic inventory)ansible-playbook -vvv launch.yml -l wiki.example.com --user=root -e do_name=wiki.example.com --start-at-task='remove empty wiki schema from database if it already exists'
start at a particular point in the task listphp -r 'var_dump(json_decode(file_get_contents("/tmp/facts/localhost"), true));'
look at the json with php (or more interesting tools) With Ansible's Jinja2 filters, you can specify the output of a variable to be 'pretty' {{ some_variable | to_nice_json }}
Variables[edit | edit source]
- You have 3 plays in one playbook. Will play 3 be able to reference facts registered in play 1?
- facts, yes, play vars, no
- vars associated to the host, persist, vars defined in the play, do not, set_facts, registered vars and gathered facts associate to the host so those do persist for the run
Playbooks[edit | edit source]
Ansible "Playbooks" use an easy and descriptive language based on YAML.
Roles[edit | edit source]
8 steps to developing an Ansible role (aka when a playbook becomes a re-usable role)
Targets[edit | edit source]
Ansible can deploy to virtualization environments and public and private cloud environments including VMWare, OpenStack, AWS, Eucalyptus Cloud, KVM, and CloudStack
Testing[edit | edit source]
Jeff Geerling talks about the spectrum of testing you can employ in your Ansible deployments[6]
yamllint
ansible-playbook --syntax-check
ansible-lint
https://ansible.readthedocs.io/projects/lint/ TLDR; you might want to setup a venv and then pip3 install ansible-lint- molecule test (integration)
ansible-playbook --check
(against prod)- parallel infrastructure
In development
- Use the debug module
- Use the fail module to fail
- Use the assert module to make assertions (and fail if they don't match)
Best Practices[edit | edit source]
Building Ansible Automation Platform execution environments (EE)
Using Python 3
- https://docs.ansible.com/ansible/latest/reference_appendices/python_3_support.html
- https://docs.ansible.com/ansible/latest/dev_guide/developing_python_3.html
- Use tags to organize your Ansible work
- Use caching (default is off) to be able to refer to host 'facts' without having to hit each host in a playbook.
- Use register of variables to create more 'facts'. Results vary from module to module. Use -v to see possible values.
- There is an order of precedence with playbook variables, with role defaults the lowest priority and extra vars the winner.
- The array notation is preferred over the dot notation for accessing variables.
{{ ansible_eth0["ipv4"]["address"] }} over {{ ansible_eth0.ipv4.address }} because some keywords in Python would conflict
- Reserved words:
- hostvars
- group_names
- groups
- environemnt
inventory_hostname
is the name of the hostname as configured in Ansible's inventory host file.ansible_hostname
is the discovered hostname
- You can use a variables file to put sensitive data in a different file (one excluded from git).
- hosts: all
remote_user: root
vars:
favcolor: blue
vars_files:
- /vars/top_secret.yml
- You can use variables on the command line (and besides key=value pairs, you can use json or yml)
---
- hosts: '{{ hosts }}'
remote_user: '{{ user }}'
tasks:
- ...
ansible-playbook release.yml --extra-vars "hosts=vipers user=starbuck"
- Check Performance Tuning like enabling
pipelining
which is off by default.
- Truthy values should always be expressed as one of
[false, true]
. Although the Ansible docs show that you can use several forms of expression for boolean values, and the YAML spec specifies a fuller range of possibilities described below, the Ansible documentation now also clarifies that only lowercase 'true' or 'false' is compatible with yamllint options.
- YAML boolean values, not Ansible
y|Y|yes|Yes|YES|n|N|no|No|NO |true|True|TRUE|false|False|FALSE |on|On|ON|off|Off|OFF
Scope[edit | edit source]
Ansible has 3 main scopes:
Global: this is set by config, environment variables and the command line Play: each play and contained structures, vars entries, include_vars, role defaults and vars. Host: variables directly associated to a host, like inventory, facts or registered task outputs
Another aspect of scope is includes vs. imports and loosely speaking, control structures like loop and the deprecated with_items
- https://stackoverflow.com/questions/68863854/iterate-list-within-role-task-provide-each-element-as-vars-to-include-tasks
- https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_reuse.html#comparing-includes-and-imports-dynamic-and-static-re-use
Ansible with VSCode[edit | edit source]
https://marketplace.visualstudio.com/items?itemName=redhat.ansible
Ansible with Vagrant[edit | edit source]
https://docs.ansible.com/ansible/guide_vagrant.html and Private:QualityBox/Vagrant
Ansible with MediaWiki[edit | edit source]
https://github.com/Orain I've cloned the 'ansible-playbook'
Ansible with Drupal[edit | edit source]
- Jeff Geerling (geerlingguy) has his code on github https://github.com/geerlingguy/drupal-vm, and also a website http://www.drupalvm.com/. He's the author of Ansible for DevOps. The only problem I see with his code is that it installs everything from his own 'roles' (individual components) via the sharing site/mechanism called Ansible Galaxy. So, for example, phpMyAdmin comes from https://github.com/geerlingguy/ansible-role-phpmyadmin This is good in that he can make his system work, but it's bad in that you're getting all your bits from him and can't tweak any of it without manually checking each role for the code and instructions behind it so you know what you can set via variables and such. I'd rather see each of these roles contained in the project, community sourced, installed via git.
geerlingguy.firewall geerlingguy.git geerlingguy.apache geerlingguy.memcached geerlingguy.mysql geerlingguy.php geerlingguy.php-pecl geerlingguy.php-memcached geerlingguy.php-mysql geerlingguy.php-xdebug geerlingguy.php-xhprof geerlingguy.phpmyadmin geerlingguy.composer geerlingguy.drush geerlingguy.daemonize geerlingguy.mailhog geerlingguy.java geerlingguy.solr
Ansible in the cloud[edit | edit source]
Ansible has several core modules for working with various cloud providers. These include
- Amazon
- Digital Ocean http://docs.ansible.com/digital_ocean_module.html
- Linode http://docs.ansible.com/linode_module.html
- LXC
- OpenStack
Ansible on Fedora[edit | edit source]
The Fedora Project uses Ansible in it's Infrastructure team, and they publish their whole setup https://infrastructure.fedoraproject.org/cgit/ansible.git/tree/README
Ansible on Rocky Linux[edit | edit source]
If you're working on Meza, you're going to want to test things on Rocky Linux 8 - because that is the reference OS for the "Common Meza Test Environment". Jeff Geerling has a Rocky Linux 8 Docker setup for testing Ansbile. Similar to installing Meza on an existing server it should be relatively quick to spin up Meza on Docker.
# from your host
docker pull geerlingguy/docker-rockylinux8-ansible:latest
cd ~/src/meza/
docker run --detach --privileged --volume=/sys/fs/cgroup:/sys/fs/cgroup:rw --cgroupns=host --volume=`pwd`:/etc/ansible/roles/role_under_test:ro geerlingguy/docker-rockylinux8-ansible:latest
# then inside the container
cd /etc/ansible/roles/role_under_test/config
ansible-playbook ../src/playbooks/site.yml --syntax-check
Ansible Docs[edit | edit source]
Some of the docs pages I've visited
- https://docs.ansible.com/ansible/playbooks_intro.html
- https://docs.ansible.com/ansible/intro_inventory.html
- http://docs.ansible.com/playbooks_best_practices.html
- http://docs.ansible.com/playbooks_loops.html
- https://docs.ansible.com/ansible/playbooks_conditionals.html
- https://docs.ansible.com/ansible/playbooks_startnstep.html
- https://docs.ansible.com/ansible/playbooks_roles.html#task-include-files-and-encouraging-reuse
- http://docs.ansible.com/YAMLSyntax.html
- https://docs.ansible.com/ansible/become.html
- https://docs.ansible.com/ansible/debug_module.html
- https://docs.ansible.com/ansible/playbooks_debugger.html (
strategy:debug
) - https://docs.ansible.com/ansible/playbooks_conditionals.html#sts=The When Statement%C2%B6
Controlling Whitespace in Jinja2 Templates[edit | edit source]
See Controlling whitespace in Jinja2 templates
Ansible References[edit | edit source]
- http://tjelvarolsson.com/blog/taking-the-effort-out-of-server-configuration-using-ansible/
- http://tjelvarolsson.com/blog/how-to-create-automated-and-reproducible-work-flows-for-installing-scientific-software/ < with Vagrant
- http://jpmens.net/2012/06/06/configuration-management-with-ansible/
- Jinja - the template engine for Ansible
- Dan's Cheat Sheets
To Do[edit | edit source]
- Follow and learn from Jeff Geerling's Drupal site https://github.com/geerlingguy/jeffgeerling-com because his techniques embody best practices for PHP, Drupal, Docker, Ansible, etc. In episode 12 of Ansible 101 - Real-world Ansible Playbooks here he discusses his Drupal playbook and the 'deploy' tag. But sadly the playbooks are private (Midwestern Mac infrastructure), so you'll have to read the screen to emulate it exactly. The closest I found was https://github.com/geerlingguy/ansible-awx-varnish-php-app/blob/master/main.yml
- Add info (separate page) about the Ansible clone of the Ruby deployment system 'Capistrano' called 'Anistrano'
References[edit source]
- ↑ In 2024 people are still Confused about Ansible documentation and versions It's rather ridiculous that their ansible-core project does NOT use SemVer
- ↑ Having the source makes it easy to upgrade, and it's self-contained, plus best of all you get all the examples and contribs.
- ↑ https://stackoverflow.com/questions/25230376/how-to-automatically-install-ansible-galaxy-roles
- ↑ Supposedly this only works for newer versions of Ansible, per the warning on their homepage:
Warning alert:To be able to download content from galaxy it is required to have ansible-core>=2.13.9 Please, check it running the command: ansible --version
But, it worked fine for me in the Meza 1_39 upgrade using Ansible 2.9.27
- ↑ Choosing which host(s) to operate on https://docs.ansible.com/ansible/intro_patterns.html
- ↑ https://www.youtube.com/live/FaXVZ60o8L8?si=gFoxE-ig5X0psuul&t=1244