How to manipulate list variable in Jinja2 template?

I’ve created a role which stores the unreachable hosts in a variable:

- block:
  - set_fact:
      unreachable_hosts: "{{ ansible_play_hosts_all|difference(ansible_play_hosts) }}"
  - debug:
      var: unreachable_hosts
  run_once: true

Depending on the amount of unreachable hosts this returns something like this:

"unreachable_hosts": [
    "server001",
    "server003"
]

In another role I’m creating an HTML file with Jinja2 template. In that HTML file I’d like to list all unreachable hosts per line (in a table row). I tried to make a for-loop in my HTML code like this:

  <tr>
    <td colspan="6">
        <b> Unreachable Servers: </b> <br>
          <ul>
          {% for items in unreachable_hosts %}
            <li font color="red">{{ unreachable_hosts }} </li>
            {% endfor %}
         </ul>
    </td>
  </tr>

But this creates an output like this:

Unreachable Servers:

- ['server001', 'server003']
- ['server001', 'server003']

I’d like to manipulate the output to look like this:

Unreachable Servers:

- server001
- server003

>Solution :

In your loop, items is an item in the unreachable_hosts list. To output one of the items being iterated over:

{% for items in unreachable_hosts %}
  <li font color="red">{{ items }} </li>
{% endfor %}

(I would also rename items to item (singular) since it contains a single item.)