Ansible: Difference between revisions

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== Best Practices ==

~~Use tags to organize your~~ Ansible ~~work~~

Building Ansible Automation Platform execution environments (EE)

* https://www.redhat.com/architect/ansible-execution-environment-tips

~~Use caching (default is off) to be able to refer to host 'facts' without having to hit each host in a playbook~~.

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 ~~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.~~

* Use tags to organize your Ansible work

~~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~~.

* Use caching (default is off) to be able to refer to host 'facts' without having to hit each host in a playbook.

The array notation is preferred over the dot notation for accessing variables.

* 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:

* Reserved words:

* hostvars

** hostvars

* group_names

** group_names

* groups

** groups

* environemnt

** environemnt

'''inventory_hostname''' is the name of the hostname as configured in Ansible's inventory host file. '''ansible_hostname''' is the discovered hostname

* '''<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).

* You can use a variables file to put sensitive data in a different file (one excluded from git).

- hosts: all

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</source>

You can use variables on the command line (and besides key=value pairs, you can use json or yml)

* You can use variables on the command line (and besides key=value pairs, you can use json or yml)

---

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<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.

* 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.

* 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>

@@ Line 96: / Line 96: @@
 == Best Practices ==
-Use tags to organize your Ansible work
+Building Ansible Automation Platform execution environments (EE)
+* https://www.redhat.com/architect/ansible-execution-environment-tips
-Use caching (default is off) to be able to refer to host 'facts' without having to hit each host in a playbook.
+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 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.
+* Use tags to organize your Ansible work
-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.
+* Use caching (default is off) to be able to refer to host 'facts' without having to hit each host in a playbook.
-The array notation is preferred over the dot notation for accessing variables.
+* 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:
+* Reserved words:
-* hostvars
+** hostvars
-* group_names
+** group_names
-* groups
+** groups
-* environemnt
+** environemnt
-'''inventory_hostname''' is the name of the hostname as configured in Ansible's inventory host file.  '''ansible_hostname''' is the discovered hostname
+* '''<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).
+* You can use a variables file to put sensitive data in a different file (one excluded from git).
 <source lang="yaml">
 - hosts: all
@@ Line 125: / Line 132: @@
 </source>
-You can use variables on the command line (and besides key=value pairs, you can use json or yml)
+* You can use variables on the command line (and besides key=value pairs, you can use json or yml)
 <source lang="yaml">
 ---
@@ Line 137: / Line 144: @@
 <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.
+* 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.
+* 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>