Difference between revisions of "Ansible"
(27 intermediate revisions by 2 users not shown) | |||
Line 1: | Line 1: | ||
[[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 | [[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+ | A lot of this page is outdated. | ||
+ | |||
+ | |||
+ | 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. | ||
+ | |||
+ | ==Installation== | ||
+ | The preferred way to [http://docs.ansible.com/intro_installation.html install] is to just <code>git clone</code> the source. Having the source makes it easy to upgrade, and it's self-contained, plus best of all you get all the examples and contribs. | ||
+ | |||
+ | <source lang="bash"> | ||
+ | cd | ||
+ | mkdir ~/bin | ||
+ | cd bin | ||
+ | git clone git://github.com/ansible/ansible.git --recursive | ||
+ | cd ./ansible | ||
+ | source ./hacking/env-setup | ||
+ | </source> | ||
+ | |||
+ | If you see this error message: | ||
+ | <pre> | ||
+ | Traceback (most recent call last): | ||
+ | File "/usr/local/bin/ansible-playbook", line 44, in <module> | ||
+ | import ansible.constants as C | ||
+ | ImportError: No module named ansible.constants | ||
+ | </pre> | ||
+ | Be sure to source the env-setup script | ||
+ | |||
+ | ==Getting Started== | ||
+ | You must source the environment setup script to begin using Ansible (assuming you are running from a git checkout) <code>source ~/bin/ansible/hacking/env-setup</code> | ||
Ansible provides three main commands: | Ansible provides three main commands: | ||
− | |||
− | |||
− | |||
− | == Modules == | + | #<code>ansible-playbook</code> - to execute an Ansible playbook on the specified systems |
+ | #<code>ansible</code> - to execute an individual shell command or Ansible module on the specified systems | ||
+ | #<code>ansible-vault</code> - (optional) to encrypt or decrypt YAML files that Ansible uses. | ||
+ | |||
+ | ===Global Config=== | ||
+ | <code>export ANSIBLE_HOST_KEY_CHECKING=False</code> | ||
+ | or set it in your ~/.ansible.cfg so that as you add new hosts it won't prompt you. | ||
+ | |||
+ | Also [https://docs.ansible.com/ansible/intro_getting_started.html#your-first-commands use 'ssh' instead of paramiko] when doing this. | ||
+ | |||
+ | ===Initialize a Project=== | ||
+ | Use '''[https://galaxy.ansible.com/ui/ Ansible Galaxy]''' If you want to do a new project, you can use the <code>ansible-galaxy foo init</code> 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" <code> ansible-galaxy install -r </code> Or, setup a 'requirements.yml' file in your playbook that then gets run by your stack. <ref>https://stackoverflow.com/questions/25230376/how-to-automatically-install-ansible-galaxy-roles</ref> <ref>Supposedly this only works for newer versions of Ansible, per the warning on their homepage:<blockquote> 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</blockquote> | ||
+ | |||
+ | '''But''', it worked fine for me in the Meza 1_39 upgrade using Ansible 2.9.27 | ||
+ | </ref> | ||
+ | |||
+ | <code>ansible-galaxy [delete|import|info|init|install|list|login|remove|search|setup] [--help] [options]</code> | ||
+ | |||
+ | ==Modules== | ||
Ansible comes with [https://docs.ansible.com/ansible/modules_by_category.html over 200 modules] that you should get familiar with in order to use the system effectively. | Ansible comes with [https://docs.ansible.com/ansible/modules_by_category.html 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 [https://docs.ansible.com/ansible/mysql_db_module.html MySQL module], the [https://docs.ansible.com/ansible/monit_module.html Monit module], or the [https://docs.ansible.com/ansible/file_module.html File module] and other interesting modules like jabber, mail, sendgrid, dpkg_selections, composer, yum, redhat_subscription, [https://github.com/ansible/ansible-modules-core/blob/devel/cloud/digital_ocean/digital_ocean.py digital ocean], the [https://docs.ansible.com/ansible/authorized_key_module.html authorized_key module] for working with SSH keys, and a whole section of [https://docs.ansible.com/ansible/list_of_system_modules.html system modules]. | |
− | # <code>ansible -m setup wiki.example.com</code> | + | You can use the '''command module''' (secure but simple) or the '''[https://docs.ansible.com/ansible/shell_module.html 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. |
− | # <code>ansible all -m setup -a "filter=ansible_distribution*"</code> use a filter action to see specific variables | + | |
+ | To sanitize any variables passed to the shell module, you should use <nowiki>"{{ var | quote }}" instead of just "{{ var }}"</nowiki> to make sure they don't include evil things like semicolons. | ||
+ | |||
+ | |||
+ | ==Example Commands== | ||
+ | Note: control verbosity with <code>-vvvv</code> | ||
+ | |||
+ | #<code>ansible --help</code> display help | ||
+ | #<code>ansible --version</code> show version info | ||
+ | #<code>ansible -c local -i ~/ansible_hosts -m ping all</code> ping all the hosts in the inventory file | ||
+ | #<code>ansible '''-m setup''' wiki.example.com</code> Use the '''[https://docs.ansible.com/ansible/latest/setup_module.html setup]''' module to gather ansible 'facts' (aka [[ansible_variables]]) about that host. | ||
+ | #<code>ansible '''localhost''' -m setup -a 'gather_subset=!all'</code> or look at the localhost | ||
+ | #<code>ansible all -m setup -a '''"filter=ansible_distribution*"'''</code> use a filter action to see specific variables | ||
+ | #<code>ansible localhost -m setup --tree /tmp/facts</code> store all facts in a file 'tree', based on hostname | ||
#<code>ansible -m debug -a "var=hostvars['wiki.example.com']" localhost</code> gives you the '[[ansible hostvars]]' | #<code>ansible -m debug -a "var=hostvars['wiki.example.com']" localhost</code> gives you the '[[ansible hostvars]]' | ||
− | # <code>ansible-playbook play1.yml play2.yml</code> Run multiple playbooks | + | #<code>ansible-playbook play1.yml play2.yml</code> Run multiple playbooks |
− | # <code>~/bin/ansible/contrib/inventory/digital_ocean.py --list --pretty --api-token TOKEN_HERE</code> use the DO api to list your droplets (dynamic inventory) | + | #<code>ansible-playbook -i production webservers.yml --tags ntp '''--list-tasks'''</code> confirm what task names would be run if I ran this command and said "just ntp tasks" |
+ | #<code>ansible-playbook '''--list-tags''' launch.yml</code> see what tags exist in my playbook (the tasks list shows more detail + the tags) | ||
+ | #<code>ansible-playbook -i production webservers.yml --limit boston '''--list-hosts'''</code> confirm what hostnames might be communicated with if I said "limit to boston" <ref>Choosing which host(s) to operate on https://docs.ansible.com/ansible/intro_patterns.html</ref> | ||
+ | #<code>~/bin/ansible/contrib/inventory/digital_ocean.py --list --pretty --api-token TOKEN_HERE</code> use the DO api to list your droplets (dynamic inventory) | ||
+ | #<code>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'</code> start at a particular point in the task list | ||
+ | #<code>php -r 'var_dump(json_decode(file_get_contents("/tmp/facts/localhost"), true));'</code> 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' <nowiki>{{ some_variable | to_nice_json }}</nowiki> | ||
+ | |||
+ | ==Variables== | ||
− | + | ;You have 3 plays in one playbook. Will play 3 be able to reference facts registered in play 1?: | |
− | ; You have 3 plays in one playbook. Will play 3 be able to reference facts registered in play 1?: | + | :facts, yes, play vars, no |
− | : 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 |
− | : 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 == | + | ==Playbooks== |
Ansible "[http://docs.ansible.com/playbooks.html Playbooks]" use an easy and descriptive language based on YAML. | Ansible "[http://docs.ansible.com/playbooks.html Playbooks]" use an easy and descriptive language based on YAML. | ||
− | == Targets == | + | ==Roles== |
+ | [https://www.redhat.com/sysadmin/developing-ansible-role 8 steps to developing an Ansible role] (aka when a playbook becomes a re-usable role) | ||
+ | |||
+ | ==Targets== | ||
Ansible can deploy to virtualization environments and public and private cloud environments including VMWare, OpenStack, AWS, Eucalyptus Cloud, KVM, and CloudStack | Ansible can deploy to virtualization environments and public and private cloud environments including VMWare, OpenStack, AWS, Eucalyptus Cloud, KVM, and CloudStack | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | == Ansible with MediaWiki == | + | ==Testing== |
+ | {{#evu:https://www.youtube.com/watch?v=FaXVZ60o8L8&t=1244s | ||
+ | |alignment=right | ||
+ | }} | ||
+ | |||
+ | |||
+ | [[File:Ansible linting and testing spectrum.png|thumb|left|The spectrum of testing you can employ in your Ansible deployments]] | ||
+ | Jeff Geerling talks about the spectrum of testing you can employ in your Ansible deployments<ref>https://www.youtube.com/live/FaXVZ60o8L8?si=gFoxE-ig5X0psuul&t=1244</ref> | ||
+ | |||
+ | #<code>yamllint</code> | ||
+ | #<code>ansible-playbook --syntax-check</code> | ||
+ | #<code>ansible-lint</code> https://ansible.readthedocs.io/projects/lint/ TLDR; you might want to setup a venv and then pip3 install ansible-lint | ||
+ | #molecule test (integration) | ||
+ | #<code>ansible-playbook --check</code> (against prod) | ||
+ | #parallel infrastructure | ||
+ | |||
+ | In development | ||
+ | |||
+ | #Use the <tt>debug</tt> module | ||
+ | #Use the <tt>fail</tt> module to fail | ||
+ | #Use the <tt>assert</tt> module to make assertions (and fail if they don't match) | ||
+ | |||
+ | ==Best Practices== | ||
+ | Building Ansible Automation Platform execution environments (EE) | ||
+ | |||
+ | *https://www.redhat.com/architect/ansible-execution-environment-tips | ||
+ | |||
+ | 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 [https://docs.ansible.com/ansible/playbooks_variables.html variables] to create more 'facts'. Results vary from module to module. Use -v to see possible values. | ||
+ | |||
+ | *There is an order of precedence with [https://docs.ansible.com/ansible/playbooks_variables.html 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.<br /> | ||
+ | |||
+ | <nowiki>{{ ansible_eth0["ipv4"]["address"] }} over {{ ansible_eth0.ipv4.address }}</nowiki> because some keywords in Python would conflict | ||
+ | |||
+ | *Reserved words: | ||
+ | **hostvars | ||
+ | **group_names | ||
+ | **groups | ||
+ | **environemnt | ||
+ | |||
+ | *'''<code>inventory_hostname</code>''' is the name of the hostname as configured in Ansible's inventory host file. '''<code>ansible_hostname</code>''' is the discovered hostname | ||
+ | |||
+ | *You can use a variables file to put sensitive data in a different file (one excluded from git). | ||
+ | <source lang="yaml"> | ||
+ | - hosts: all | ||
+ | remote_user: root | ||
+ | vars: | ||
+ | favcolor: blue | ||
+ | vars_files: | ||
+ | - /vars/top_secret.yml | ||
+ | </source> | ||
+ | |||
+ | *You can use variables on the command line (and besides key=value pairs, you can use json or yml) | ||
+ | <source lang="yaml"> | ||
+ | --- | ||
+ | |||
+ | - hosts: '{{ hosts }}' | ||
+ | remote_user: '{{ user }}' | ||
+ | |||
+ | tasks: | ||
+ | - ... | ||
+ | </source> | ||
+ | <code>ansible-playbook release.yml --extra-vars "hosts=vipers user=starbuck"</code> | ||
+ | |||
+ | *Check [https://www.ansible.com/blog/ansible-performance-tuning Performance Tuning] like enabling <code>pipelining</code> which is off by default. | ||
+ | |||
+ | *Truthy values should always be expressed as '''one of <code>[false, true]</code>'''. Although the Ansible docs show that [https://docs.ansible.com/ansible/latest/YAMLSyntax.html#yaml-basics you can use several forms of expression for boolean values], and [http://yaml.org/type/bool.html the YAML spec specifies a fuller range of possibilities] described below, the Ansible documentation now also [https://docs.ansible.com/ansible/latest/reference_appendices/YAMLSyntax.html clarifies that only lowercase 'true' or 'false'] is compatible with [[yamllint]] options. | ||
+ | |||
+ | ;YAML boolean values, not Ansible: | ||
+ | :<syntaxhighlight lang="ebnf"> | ||
+ | y|Y|yes|Yes|YES|n|N|no|No|NO | ||
+ | |true|True|TRUE|false|False|FALSE | ||
+ | |on|On|ON|off|Off|OFF | ||
+ | </syntaxhighlight> | ||
+ | |||
+ | ==Scope== | ||
+ | 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 <tt>includes</tt> vs. <tt>imports</tt> and loosely speaking, control structures like <tt>loop</tt> and the deprecated <tt>with_items</tt> | ||
+ | |||
+ | *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== | ||
+ | https://marketplace.visualstudio.com/items?itemName=redhat.ansible | ||
+ | |||
+ | ==Ansible with Vagrant== | ||
+ | https://docs.ansible.com/ansible/guide_vagrant.html and [[Private:QualityBox/Vagrant]] | ||
+ | |||
+ | ==Ansible with MediaWiki== | ||
https://github.com/Orain | https://github.com/Orain | ||
I've cloned the '[https://github.com/freephile/ansible-playbook.git ansible-playbook]' | I've cloned the '[https://github.com/freephile/ansible-playbook.git ansible-playbook]' | ||
− | == Ansible with Drupal == | + | ==Ansible with Drupal== |
− | * 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. | + | |
+ | *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. | ||
<pre> | <pre> | ||
geerlingguy.firewall | geerlingguy.firewall | ||
Line 66: | Line 229: | ||
</pre> | </pre> | ||
− | * on [https://www.digitalocean.com/community/tutorials/how-to-create-an-ansible-playbook-to-automate-drupal-installation-on-ubuntu-14-04 Digital Ocean] | + | *on [https://www.digitalocean.com/community/tutorials/how-to-create-an-ansible-playbook-to-automate-drupal-installation-on-ubuntu-14-04 Digital Ocean] |
− | == Ansible in the cloud == | + | ==Ansible in the cloud== |
Ansible has several core modules for working with various [http://docs.ansible.com/list_of_cloud_modules.html cloud providers]. These include | Ansible has several core modules for working with various [http://docs.ansible.com/list_of_cloud_modules.html cloud providers]. These include | ||
− | * Amazon | + | *Amazon |
− | * [[Digital Ocean]] http://docs.ansible.com/digital_ocean_module.html | + | *[[Digital Ocean]] http://docs.ansible.com/digital_ocean_module.html |
− | * [[Linode]] http://docs.ansible.com/linode_module.html | + | *[[Linode]] http://docs.ansible.com/linode_module.html |
− | * [[LXC]] | + | *[[LXC]] |
− | * OpenStack | + | *OpenStack |
− | == 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 Docs == | + | ==Ansible Docs== |
Some of the docs pages I've visited | Some of the docs pages I've visited | ||
− | * https://docs.ansible.com/ansible/playbooks_intro.html | + | *https://docs.ansible.com/ansible/playbooks_intro.html |
− | * https://docs.ansible.com/ansible/intro_inventory.html | + | *https://docs.ansible.com/ansible/intro_inventory.html |
− | * http://docs.ansible.com/playbooks_best_practices.html | + | *http://docs.ansible.com/playbooks_best_practices.html |
− | * http://docs.ansible.com/playbooks_loops.html | + | *http://docs.ansible.com/playbooks_loops.html |
− | * https://docs.ansible.com/ansible/playbooks_conditionals.html | + | *https://docs.ansible.com/ansible/playbooks_conditionals.html |
− | * https://docs.ansible.com/ansible/playbooks_startnstep.html | + | *https://docs.ansible.com/ansible/playbooks_startnstep.html |
− | * https://docs.ansible.com/ansible/playbooks_roles.html#task-include-files-and-encouraging-reuse | + | *https://docs.ansible.com/ansible/playbooks_roles.html#task-include-files-and-encouraging-reuse |
− | * http://docs.ansible.com/YAMLSyntax.html | + | *http://docs.ansible.com/YAMLSyntax.html |
− | * https://docs.ansible.com/ansible/become.html | + | *https://docs.ansible.com/ansible/become.html |
− | * https://docs.ansible.com/ansible/debug_module.html | + | *https://docs.ansible.com/ansible/debug_module.html |
− | * https://docs.ansible.com/ansible/playbooks_debugger.html (<code>strategy:debug</code>) | + | *https://docs.ansible.com/ansible/playbooks_debugger.html (<code>strategy:debug</code>) |
− | * https://docs.ansible.com/ansible/playbooks_conditionals.html#sts=The When Statement%C2%B6 | + | *https://docs.ansible.com/ansible/playbooks_conditionals.html#sts=The When Statement%C2%B6 |
+ | |||
+ | |||
+ | ==Controlling Whitespace in Jinja2 Templates== | ||
+ | See [[Controlling whitespace in Jinja2 templates]] | ||
+ | |||
+ | ==Ansible References== | ||
+ | *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/ | ||
+ | *[http://jinja.pocoo.org/docs/dev/ Jinja] - the template engine for Ansible | ||
+ | *[https://cheat.readthedocs.io/en/latest/ansible/index.html Dan's Cheat Sheets] | ||
− | == | + | == To Do == |
− | |||
− | |||
− | |||
− | |||
+ | # 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 [https://www.youtube.com/live/_QZr4xKhir4?si=LOyBibByqdmLb7M6&t=1107 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' | ||
+ | ## https://www.oliverdavies.uk/talks/deploying-php-ansible-ansistrano | ||
+ | ## https://github.com/ansistrano/deploy | ||
+ | {{References}} | ||
+ | [[Category:Virtualization]] | ||
[[Category:Configuration Management]] | [[Category:Configuration Management]] | ||
[[Category:DevOps]] | [[Category:DevOps]] |
Revision as of 15:37, 12 April 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.
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.
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 Docs
- 19 Controlling Whitespace in Jinja2 Templates
- 20 Ansible References
- 21 To Do
- 22 References
Installation[edit | edit source]
The preferred way to install is to just git clone
the source. Having the source makes it easy to upgrade, and it's self-contained, plus best of all you get all the examples and contribs.
cd
mkdir ~/bin
cd bin
git clone git://github.com/ansible/ansible.git --recursive
cd ./ansible
source ./hacking/env-setup
If you see this error message:
Traceback (most recent call last): File "/usr/local/bin/ansible-playbook", line 44, in <module> import ansible.constants as C ImportError: No module named ansible.constants
Be sure to source the env-setup script
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. [1][2]
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" [3]~/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[4]
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 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]
- ↑ 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