CODEWITHSUNDEEP
ansible
Hastux
Hastux

Reputation: 81

Ansible - How to set a var with a loop

I would like to create a complex var (nginx_ssl_vhosts_list) with a loop from another simple var (reverse_proxy_ssl) but I'm unable to get this to work. Is it possible to have something like the following code or shall I use a custom plugin?

Here is what how I thought it would have worked:

- hosts: localhost
  gather_facts: no
  connection: local
  vars:
    reverse_proxy_ssl:
      - name: foo.org
        frontport: 443
        fronturl : /
        backend: http://192.168.1.1:8080
      - name: bar.org
        frontport: 443
        fronturl : /
        backend: http://192.168.1.2:443
    nginx_ssl_vhosts_list:
      - listen: "{{ item.frontport }} ssl"
        server_name: "{{ item.name }}"
        access_log: "{{ item.name }}.access.log"
        error_log: "{{ item.name }}.error.log"
        extra_parameters: |
          location {{ item.fronturl }} {
            proxy_pass {{ item.backend }};
          }
          ssl_certificate     {{ item.name }}.crt;
          ssl_certificate_key {{ item.name }}.key;
      with_items: "{{ reverse_proxy_ssl }}"
  tasks:
    - debug: msg="{{ nginx_ssl_vhosts_list }}"

Upvotes: 8

Views: 24051

Answers (3)

MacFreek
MacFreek

Reputation: 3446

I'm aware this is an old question, but I had a similar problem. Here is my approach.

First, I think @ydaetskcoR is right that the best place to solve this is NOT to create a complex variable, but move loops to the template.

That said, there are some cases where you want to loop over dicts or lists. In my case, because I wanted to ensure that every required key was set in a list of dicts, and if not, fill in a default, that depends on some logic that was to convoluted to write in a template.

The approach by sonance207 seems very powerful, but I noted that I got some incompatibilities by the "set" variables, which are defined by Jinja2, and the filters and variables set by Ansible. E.g in the above example, the line

{%- set _= temp_dic.update({'var': vars.var }) -%}

can't be written as

{%- set temp_dic = temp_dic | combines({'var': vars.var }) -%}

If you do that, you get weird errors, like Ansible thinking that temp_dic is None instead of a dictionary.

In the end, I used a simplified version of what's written by Konstantin Suvorov on https://ansibledaily.com/process-complex-variables-with-set_fact-and-with_items/. However, instead of writing to a temporary variable with the register keyword, and retrieving it later, I simply opted for a simple with_item loop that grew the desired nginx_ssl_vhosts_list variable with a single entry each loop.

- hosts: localhost
  gather_facts: no
  connection: local
  vars:
    reverse_proxy_ssl:
      - name: foo.org
        frontport: 443
        fronturl : /
        backend: http://192.168.1.1:8080
      - name: bar.org
        frontport: 443
        fronturl : /
        backend: http://192.168.1.2:443
    nginx_ssl_vhosts_list: []
  tasks:
    - set_fact:
        nginx_ssl_vhosts_list: "{{ nginx_ssl_vhosts_list + [{
          'listen': (item.frontport |string) + ' ssl',
          'server_name': item.name,
          'access_log': item.name + '.access.log',
          'error_log': item.name + '.error.log'
        }] }}"
      with_items: "{{ reverse_proxy_ssl }}"

    - debug: msg="{{ nginx_ssl_vhosts_list }}"

(Note that this example leaves out the multi-line formatting of extra_parameters. Such formatting are best served in a jinja2 template file.

Upvotes: 2

jmcgrath207
jmcgrath207

Reputation: 2087

This is possible.

I did this by using Jinja2 templating and using normal python inside the templating. At the end just return the list with {{- temp_list -}}

Here is a example from my default/main.yml

# Arch List type
Mock_ArchType: ['epel-6-x86_64','epel-7-x86_64']

# Vars list Dictionary
Platform_Vars_list: [
{ var: "log_path", value: "'{{ Default_Home_String }}/logs/'" },
{ var: "python_site_packages_path", value: "'{{ Default_Python_String }}/lib/python{{ python_main_version }}/site-packages/'" }
                         ]

Platform_Vars:      "{%- set temp_list = [] -%}
                     {%- for item in Mock_ArchType if (client_code | search('Build')) -%}
                     {%- for vars in Platform_Vars_list  -%}
                     {%- set temp_dic = {} -%}
                     {%- set _= temp_dic.update({'var': vars.var }) -%}
                     {%- set _= temp_dic.update({'value': vars.value }) -%}
                     {%- set _= temp_dic.update({'path': '/var/lib/mock/' + item + '/root/builddir/build/BUILDROOT' + Default_Home_String }) -%}
                     {%- set _= temp_list.append(temp_dic) -%}
                     {%- endfor -%}
                     {%- endfor -%}
                     {{- temp_list -}}"

Credit goes to this. https://groups.google.com/forum/#!topic/ansible-project/aiBiuUGWZGs

Upvotes: 3

ydaetskcoR
ydaetskcoR

Reputation: 56997

As far as I know you can't loop in a variable definition, however you can loop inside a template or task.

In this exact case you are probably best creating a template task that generates your virtual hosts from the reverse_proxy_ssl list variable with something like this:

...
tasks:
  - name: template virtual hosts
    template:
      src: apache2.conf.j2
      dest: /etc/apache2/apache2.conf
...

apache2.conf.j2

...
{% for vhost in reverse_proxy_ssl %}
<VirtualHost *: {{ vhost.frontport }}>
    ServerName {{ vhost.name }}
    ProxyPreserveHost On
    ProxyPass {{ vhost.fronturl }} {{ vhost.backend }}
    ProxyPassReverse {{ vhost.fronturl }} {{ vhost.backend }}
</VirtualHost>
{% endfor %} 
...

In the more general case you should be able to create a variable with set_fact and use that in a loop:

- name: set foo
  set_fact: foo="{{ item.foo }}"
  with_items: foos

Upvotes: 3

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