Jinja2 has built-in option to manage loop information: loop.index: The current iteration of the loop. Conditional Statements: A conditional statement defines a condition for execution. Ansible also offers a new plugin type: Lookup Plugins. Ansible Version: v1.6.7+, devel. Posted by 2 years ago. Embed. A Jinja2 template file is a text file that contains variables that get evaluated and replaced by actual values upon runtime or code execution. Ansible supports conditional statements like when, if, if else, if elif else etc. 3. Ansible includes a lot of specialized filters and tests for templating. ansible - example of template if else. Next, we are going to explain each statement with a demo. According to Jinja2 documentation you can manage whitespace and tabular indentation with lstrip_blocks and trim_blocks options:. Ansible supports all the statements provided by Jinja2 like if else, for etc. Jinja2 ships with many of these. (0 indexed) loop.revindex: The number of iterations from the end of the loop (1 indexed) loop.revindex0: The number of iterations from the end of the loop (0 indexed) loop.first: True if first iteration. It is possible to use this in ansible templates also using the jinja2 format. Jinja is a modern and designer-friendly templating language for Python, modelled after Django’s templates. ).Defaults to False. Jinja2 is a templating language. For list of supported algorithms see link in References. Embed Embed this gist in The value of the when key is a Jinja2 expression without the curly braces. You can use the Ansible-specific filters documented here to manipulate your data, or use any of the standard filters shipped with Jinja2 - see the list of built-in filters in the official Jinja2 template documentation. Jinja can generate any text-based format (HTML, XML, CSV, LaTeX, etc.). For conditional control, Jinja2 uses the familiar if statements, which have the following syntax: The benefit of using the template module, rather than the copy module, is that the Ansible template module can use the Jinja2 templating language.Jinja2. ; lstrip_blocks: If this is set to True leading spaces and tabs are stripped from the start of a line to a block. Star 63 Fork 22 Star Code Revisions 4 Stars 63 Forks 22. Skip to main content. I did try using Jinja2 whitespace controls ({%- -%}) and they work for whitespaces as described. ).Defaults to False. Search. Traditional programming language usually uses the if-else statement when more than one outcome is expected. The task is only executed if this Jinja2 expression evaluates to true. Ansible has a pletora of ways to accomplish the same tasks. This prevents me from creating more flexible roles that can be easily customized using inventory lists. This Jinja2 expression can evaluate the value of a variable. It renders to the following: According to Jinja2 documentation you can manage whitespace and tabular indentation with lstrip_blocks and trim_blocks options:. I am using the Ansible Jinja2 if statement for this purpose. Sometimes you will want to skip a particular step on a particular host. Ansible uses Jinja2 as a template engine. All gists Back to GitHub Sign in Sign up Sign in Sign up {{ message }} Instantly share code, notes, and snippets. range() and format() in a for-loop. halberom / opt1_template.j2. Next, we are going to explain each operator type with a demo. What is Jinja2? Jinja2 code is expected in '.j2' files for templates, and inline playbooks, where some rules apply. So instead of using the if-else statement, you define what you want to happen. We have reserved a range of 20 IP addresses for VPN client endpoints. It can contain Jinja2 filters, and it can also include logical operators and groupings. Ansible supports all the operators provided by Jinja2 like math, comparison, logical and other special Jinja2 operators. Jinja2 nested if statements. The When Statement ¶ Sometimes you will want to skip a particular step on a particular host. It offers a wide range of control structures, functions and filters. Ansible playbooks are pure machine-parseable YAML. Problem: When using Ansible Jinja2 if it keeps adding "\n" to the string. GitHub Gist: instantly share code, notes, and snippets. Search . I'm either an idiot, or I just can't find it (my guess is the first option) but I'm looking for an if statement if it contains a string, something like: {% if '10.0.0.' The for loop can also take an optional else clause just like Python, however, its usage is slightly different. In addition to those, Ansible supplies many more. when: condition. What is Jinja2? In this guide, we will focus on how you can configure and use Jinja2 template in Ansible playbook. In this post I am demonstrating the use of Ansible's Jinja2 templating module, and the applications it can be utilized for within a service-provider network. ; lstrip_blocks: If this is set to True leading spaces and tabs are stripped from the start of a line to a block. On each iteration, a line with the variable is printed. Ansible Jinja template if statement. Ansible uses Jinja2 templating to enable dynamic expressions and access to variables. Below are my jinja2 template file and the variables used to populate it. A template contains variables and/or expressions, which get replaced with values when a template is rendered; and tags, which control the logic of the template. Is this possible? Ansible will look for jinja2 template files in your project directory or in a directory named templates under your project directory. The Ansible template module is mainly used to copy files from the Ansible client (where Ansible is installed) to the Ansible hosts (managed by Ansible). Share. . I'm using Ansible with Jinja2 templates, and this is a scenario that I can't find a solution for in Ansible's documentation or googling around for Jinja2 examples. Viewed 18k times 6. hash(’sha1’) will use sha1 algorithm. A Jinja template doesn’t need to have a specific extension: .html, .xml, or any other extension is just fine. Let’s dig into what they are. This is a snippet from my Ansible jinja template which populates an environment specific template. What would you like to do? Recall that in Python when a for loop is followed by an else clause, the else clause is executed only when for loop terminates after looping over the sequence or when the sequence is empty. It is shorthand for a complex if statement checking if a variable is defined before trying to use it, with an else clause to provide a different value. If nothing else, it will at least show some interesting things that can be done with Ansible and Jinja2 templates. (1 indexed) loop.index0: The current iteration of the loop. Skip to content. In this article, i’ll show how to test if a variable exists or not, if it is empty or not and if it is set to True. Jinja2 template if string contains . As you may know, Kubernetes 1.11 was recently released, and along with it a new version of kubeadm , the tool for bootstrapping Kubernetes clusters. This is why you're getting those syntax erros. Jinja¶. is a powerful Python templating language through which you can generate … . J2Live is a live Jinja2 parser/renderer, you give it template, associated values, ... ipaddr - this is a copy of ipaddr filter found in Ansible and it has the same functionality; hash - generates hash of value it’s applied to, takes hashing algorithm as an argument e.g. Hi. trim_blocks: If this is set to True the first newline after a block is removed (block, not variable tag! Close. However I want to include a new section only if aditional_keys = true. 0. When to quote variables (a YAML gotcha) ¶ If you start a value with {{foo}}, you must quote the whole expression to create valid YAML syntax. Filters in Jinja2 are a way of transforming template expressions from one kind of data into another. vars: host_fqdn: server host_fqdn: | {% if 'lab.com' in {{ host_fqdn }} %} {% host_fqdn = "{{ host_fqdn }}" %} {% else %} {% host_fqdn = "{{ host_fqdn }}.lab.com" %} {% endif %} ansible. Jinja2 template if string contains. Last active Feb 23, 2021. Ansible allows Jinja2 loops and conditionals in templates but not in playbooks. There are several useful tests that you can make using Jinja2 builtin tests and filers. You can also use Python methods to transform data. Environment: Debian, Ubuntu. Summary: Recent security fix prevents me from using Jinja2 {% if %}{% else %}{% endif %} syntax in a task. If you want to define variables for each role, one approach is to use a separate var file for each role: It is fast, widely used and secure with the optional … If the value has "lab.com" keyword in it, it should directly store the value to "host_fqdn" again or else it should add "lab.com" keyword to the value and store it to "host_fqdn" variable. It is not executed when the for loop is terminated by the break statement. Template architecture . Jinja2 nested if statements. As Network Engineers, we deal with various vendor-specific configuration syntaxes on the job. Jinja2's syntax encloses the control structures inside the {% %} blocks. Loop management¶. The When Statement ¶. In the following example, I am looping through the value 0 to 2 using the python range function. In Jinja2 templates, it is often a good practice to test if a variable exists and what value does it carry. Consider this example, where we set up (part of) a hosts file for name lookups for OpenVPN clients. There are many options to control execution flow in Ansible. Hence, it would be useful for us to understand Jinja2 control structures in addition to the ones supported by Ansible tasks. The trailing \n still exists. My variable - { name: 'container1', Few examples of applications using Jinja2 are Ansible, Django, Flask, Salt and Trac. This approach minimizes the package requirements on the target (jinja2 is only required on the controller). Ask Question Asked 2 years, 9 months ago. A Jinja template is simply a text file. As already referenced in the variables section, Ansible uses Jinja2 templating to enable dynamic expressions and access to variables. All templating happens on the Ansible controller before the task is sent and executed on the target machine. It's designer friendly and widely used in the Python ecosystem. See builtin filters in the official Jinja2 template documentation.. | trim didn't work as well. The syntax is as shown below: tasks . Active 11 months ago. I’ll also give two examples of how to combine these checks. First, allow me to explain the problem I was trying to solve. Synopsis¶. the trailing endif omits the line break. trim_blocks: If this is set to True the first newline after a block is removed (block, not variable tag! Jinja2 is a modern and designer-friendly templating language for Python, modelled after Django’s templates. Archived. In Ansible, ‘when’ statement is used instead to determine the outcome of a variable. You cannot create a loop of tasks. This could be something as simple as not installing a certain package if the operating system is a particular version, or it could be something like performing … Search form. in ansible_all_ipv4_addresses %} 10.0.0.0/24 {% endif %} This is for a CSF configuration. The Jinja templating engine that Ansible utilized under the hood can do much more though.