Ansible/Jinja2 – Loop Through Product of Two Dictionary Lists

ansible

I have two lists of dictionaries and would like to loop through the cartesian product as one. How do I do this.

sample data:

environments: [
                {title: outdoors, climate: variable},
                {title: indoors, climate: steady}
              ],
colorscheme:  [
                {top: blue, bottom: red},
                {top: pink, bottom: green}
              ]

desired result:

item: [
        {title: outdoors, climate: variable, top: blue, bottom: red},
        {title: indoors, climate: steady, top: blue, bottom: red},
        {title: outdoors, climate: variable, top: pink, bottom: green},
        {title: indoors, climate: steady, top: pink, bottom: green}
      ]

I have tried the expression "{{ environments|product(colorscheme)|list }}" which gets me close but not quite what I want.

Results of expression:

item: [
        [
          {title: outdoors, climate: variable}, 
          {top: blue, bottom: red}
        ],
        [
          {title: indoors, climate: steady},
          {top: blue, bottom: red}
        ],
        [
           {title: outdoors, climate: variable},
           {top: pink, bottom: green}
        ],
        [
           {title: indoors, climate: steady},
           {top: pink, bottom: green}
        ]
      ]

Best Answer

Here is one way you could do it. Not sure it is the best eway.

- hosts: localhost
  gather_facts: no
  vars:
    envs:
    - title: outdoors
      climate: variable
    - title: indoors
      climate: steady
    colorscheme:
    - top: blue
      bottom: red
    - top: pink
      bottom: green
  tasks:
  - debug:
      msg: >
        [
        {% for e in envs %}
        {% for c in colorscheme %}
        {{ e | combine (c) }},
        {% endfor %}
        {% endfor %}
        ]


# TASK [debug] **************************************************************************************************[3/1813$
# ok: [localhost] => {
#     "msg": [
#         {
#             "bottom": "red",
#             "climate": "variable",
#             "title": "outdoors",
#             "top": "blue"
#         },
#         {
#             "bottom": "green",
#             "climate": "variable",
#             "title": "outdoors",
#             "top": "pink"
#         },
#         {
#             "bottom": "red",
#             "climate": "steady",
#             "title": "indoors",
#             "top": "blue"
#         },
#         {
#             "bottom": "green",
#             "climate": "steady",
#             "title": "indoors",
#             "top": "pink"
#         }
#     ]
# }
#

Related Solutions

Ansible iterate a dictionary with lists

First off, you might want to consider using the file module, rather than shell. It's less failure prone, and ostensibly idempotent. However, that might give you some issues with mixing directories, files, and file globs. YMMV.

As for the heart of the question, I would set up your variables like so:

users:
  - username: bar
    directories:
      - path: /data
        permissions: rX
      - path: /js
        permissions: rX
  - username: foo
    directories:
      - path: /
        permissions: rwX

The play would then look like this:

- name: Change mod/own
  shell: chown {{ item.0.username }} {{ item.1.path }};chmod u+{{ item.1.permissions }} {{ item.1.path }
  with_subelements:
    - users
    - directories

Ansible – Appending to Lists or Adding Keys to Dictionaries

You can merge two lists in a variable with +. Say you have a group_vars file with this content:

---
# group_vars/all
pgsql_extensions:
  - ext1
  - ext2
  - ext3

And it's used in a template pgsql.conf.j2 like:

# {{ ansible_managed }}
pgsql_extensions={% for item in pgsql_extensions %}{{ item }}, {% endfor %}

You can then append extensions to the testing database servers like this:

---
# group_vars/testing_db
append_exts:
  - ext4
  - ext5
pgsql_extensions: "{{ pgsql_extensions + append_exts }}"

When the role is run in any of the testing servers, the aditional extensions will be added.

I'm not sure this works for dictionaries as well, and also be careful with spaces and leaving a dangling comma at the end of the line.

Best Answer

Related Solutions

Ansible iterate a dictionary with lists

Ansible – Appending to Lists or Adding Keys to Dictionaries

Related Topic