Loops & if Blocks in Templates
Generate repeated config sections.
Loops & if Blocks in Templates is a free Ansible Academy lesson on CoddyKit. This is lesson 3 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Ansible Academy learning path, and your progress syncs across the web and the CoddyKit app. The Ansible Academy course includes 4 lessons in total.
Logic Lives in {% %}
Beyond printing values, Jinja2 runs control logic inside {% %} tags. This is how one template generates many lines. 🔁
A Basic for Loop
Use a for loop to repeat lines over a list. Every item produces another block of rendered text.
{% for host in backends %}
server {{ host }};
{% endfor %}Always Close Your Blocks
Each opening tag needs a closing one: endfor ends a loop, just as endif ends a condition. Forgetting it breaks rendering.
Loop Over a Dictionary
Walk a dictionary's pairs with .items(), capturing each key and value to render structured config.
{% for key, val in settings.items() %}
{{ key }} = {{ val }}
{% endfor %}The loop Variable
Inside a loop, Jinja2 gives you loop.index for the current count and loop.first or loop.last as handy booleans.
{% for s in servers %}
server{{ loop.index }} {{ s }};
{% endfor %}A Simple if Block
An if block renders its body only when the condition is true, so optional config appears only when it should.
{% if enable_ssl %}
ssl on;
{% endif %}if, elif and else
Chain choices with elif and a final else. Exactly one branch renders, just like in Python.
{% if env == 'prod' %}
level = warn
{% else %}
level = debug
{% endif %}Conditions Inside Loops
Nest an if inside a for to render only matching items, like skipping disabled servers in a pool.
{% for h in hosts %}
{% if h.enabled %}
server {{ h.ip }};
{% endif %}
{% endfor %}Whitespace Control
Loops can leave blank lines behind. A dash like {%- -%} trims surrounding whitespace for tidy output.
{%- for h in hosts -%}
{{ h }}
{%- endfor -%}The else of a for Loop
A for can have an else that runs only when the list was empty, perfect for a sensible fallback line.
{% for h in backends %}
server {{ h }};
{% else %}
# no backends defined
{% endfor %}Print vs Logic Tags
Keep them straight: {{ }} outputs a value, while {% %} controls flow but prints nothing itself.
Quick Check
You want to repeat a config line for every host in a list. Which tag starts that loop?
Recap
You can now loop with for, branch with if, read loop.index, nest them and trim whitespace. One template now writes dynamic config. ✨
Frequently Asked Questions
Is the “Loops & if Blocks in Templates” lesson free?
Yes — the full text of “Loops & if Blocks in Templates” is free to read here on the web. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Ansible Academy course, upgrade to CoddyKit PRO. The Ansible Academy course includes 4 lessons in total.
What will I learn in “Loops & if Blocks in Templates”?
Generate repeated config sections. You practise Ansible Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Ansible Academy?
No prior experience is required. Ansible Academy on CoddyKit is structured for beginners through advanced learners, so you can start here or from the beginning and move at your own pace. This is lesson 3 of 4.
How long does the “Loops & if Blocks in Templates” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Ansible Academy lesson?
Yes. Every Ansible Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- The template Module & .j2 Files
- Variables & Expressions in Jinja2
- Loops & if Blocks in Templates
- Filters: default, join & upper