Templating guide on CloudBolt Documentation

Best practices

Mon, 01 Jan 0001 00:00:00 +0000

The CloudBolt OneFuse Platform leverages the Jinja2 templating language to allow our customers to define logic around how a module is to be consumed inside of a OneFuse Policy. These templates can be extremely powerful and can define very granularly exactly how OneFuse Policies should be consumed by an Upstream Provider.

However, the OneFuse Platform was designed to simplify your automation journey, so these best practices will help to better define how to mitigate complexity when building OneFuse Policies.

Property Sets

Mon, 01 Jan 0001 00:00:00 +0000

Property Sets are typically grouped in one of two main functional areas:

Property Sets for modeling OneFuse Policies
- Used for Template Previews in the OneFuse platform while building Policies with the Active Property Set.
  - Ability to validate the result of a Policy while building it, giving the user real-time feedback on exactly how the Policy will behave with a certain set of inputs.
Property Sets for Property Toolkit features
- Properties get applied to the resource being provisioned as configuration. Each property in these Property Sets is used to drive the outcomes of the resource that we are building.
- Some properties may be used to name the resource, determine the number of CPUs, or place a virtual machine in a particular cluster. Almost any aspect of the provisioned resource is capable of being influenced by these Property Sets.
- Template both key:value of the property
- Call other Property Sets within the parent Property Set

Managing Property Sets

Workspace Role needed to manage Property Sets: Admin or Member.

Quick reference

Mon, 01 Jan 0001 00:00:00 +0000

`_all_properties`

This is a Custom filter created for OneFuse to output all the Properties from the Deployment at Run Time.

The primary use-case for this is to access all the Properties when using the Scripting Module to utilize meta data within the OS scripts or to populate Ansible Host Variables which can be used for playbook executions.

Output rendered templateProperties with: _all_properties during Policy execution calls and/or Templating API.

Example

{#
  Example templateProperties stack:

  {
    "foo": "hello",
    "bar": "world"
  }
#}

{# Example 1 #}

{{ _all_properties }}


{# Example 2 #}

{% for key, value in _all_properties.items() %}
  Key: {{key}}
  Value: {{value}}
{% endfor %}


{# Example 3#}

{%for key in _all_properties %}
  {{key}}
{%endfor%}

{# Example 4 #}

{{ _all_properties.foo }}

Will not account for variables set after invocation, for example setting new variables using {%set foo = "bar" %}.

Expressions

Mon, 01 Jan 0001 00:00:00 +0000

Expressions get replaced with values when a template is rendered.

Expressions appear inside {{ ... }} tags.

Literals

The simplest form of expressions.

Boolean

true is always true and false is always false.

true
false

Dict

A dict in Python is a structure that combines keys and values.

Keys must be unique and always have exactly one value.

{
  "foo": "Hello World"
}

Integers

Integers are whole numbers without a decimal part.

Control structures

Mon, 01 Jan 0001 00:00:00 +0000

A control structure refers to all those things that control the flow: conditionals, for-loops, as well as assignments.

Control structures appear inside {% ... %} tags.

For

Loop over each item in a sequence.

{# List users provided in a variable called 'users' #}
{% for user in users %}
  {{ user.username | e }}
{% else %}
  {# Optional else block if no iteration took place because sequence was empty or the filtering removed all items from the sequence. #}
  No users found.
{% endfor %}

{#
Unlike other for loops, you cannot break or continue in a loop. Instead, use filters
#}

{% for user in users if not user.hidden %}
  {{ user.username |e }}
{% endfor %}

Special variables

Access special variables inside a for-loop block.

Tests

Mon, 01 Jan 0001 00:00:00 +0000

Tests can be used to test a variable against a common expression.

To test a variable or expression, you add the is-operator or is not-operator plus the name of the test after the variable.

{{ 21 is divisibleby(3) }}

=> true

boolean

Test returns true if the object is a boolean value.

{{ true is boolean }}

=> true

defined

Test returns true if the variable is defined.

{{ foo is defined }}

Refer to the default filter.

Filters

Mon, 01 Jan 0001 00:00:00 +0000

Filters appear inside {{ ... }} tags and are separated from the variable by a pipe symbol (|). Filters may have optional arguments in parentheses.

Multiple filters can be chained; the output of one filter is applied to the next.

{# Example 1 #}
{% set foo = ["hello", "world"] %}
{{ foo | first | upper }}


{# Example 2 #}
{# You can also apply filters on a block of template data within the filter section #}

{% filter upper %}
hello world
{% endfilter %}

Result: