Creating list of ip's in ansible using given range within jinja template

Question

i want to generate a list of ip addresses (using range of last 8bits so 120-190 translates to x.x.x.120 - x.x.x.190) in defaults/main.yml in my role, and later use it to create new network interfaces and generate a new config file. I tried this approach:

defaults/main.yml:

ip_list: "{%for address_end in range(50,99)%} 192.168.0.{{address_end}}{%endfor%}" conf_list: "{%for ip in ip_list%}server {{ip}}:6666 {%endfor%}"

and then to use it in template

template.conf.j2:

{% for conf_line in conf_list %}
{{conf_line}}
{% endfor %}

and all i got in generated config file was:

so my guess is that i'm not generating a list but just a long string and when I use for loop in template.conf.j2 I iterate over single chars. I tried using answer to this problem but all i got was syntax error. Any ideas for what might help me ?

score 7 · Accepted Answer · answered Nov 16 '16 at 16:58

7

You should format your vars as JSON lists if you want them to be lists.
1.1.1.1 2.2.2.2 3.3.3.3 is a string.
['1.1.1.1', '2.2.2.2', '3.3.3.3'] will be converted to list.

But there is alternative approach for you:

ip_list: "{{ lookup('sequence', 'start=50 count=12 format=192.168.0.%d', wantlist=True) }}"
conf_list: "{{ ip_list | map('regex_replace','(.*)','server \\1:6666') | list }}"

answered Nov 16 '16 at 16:58

Konstantin Suvorov

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the alternative aproach seems cool, but out of curiosity how would one format vars as a JSON list in my case ? – Sackhorn Nov 16 '16 at 17:23
1

follow my example list in the answer: place single quotes around ip-addresses, place comma after each address and place square brackets on both sides. – Konstantin Suvorov Nov 16 '16 at 17:31
i get how JSON lists look like but i have problems with jinja templates syntax and i wanted to know if (and how) this is applicable in my case :) – Sackhorn Nov 16 '16 at 17:37
2

`ips: "[{%for i in range(1,5)%}'192.168.0.{{i}}',{%endfor%}]"` – Konstantin Suvorov Nov 16 '16 at 19:34
^this just creates a string for me like in the example i posted. But the template code that you posted in your answer worked perfectly. Thank you very much – Sackhorn Nov 17 '16 at 14:37
@Sackhorn Maybe you are passing it through the `list` filter? It is not needed. – Nikolaos Kakouros Aug 19 '17 at 16:15

score 1 · Answer 2 · answered Nov 17 '16 at 20:07

Kostantin answer was of much help, but i found just realized that generating config entries in my case could be solved in an less complex way. Instead of trying to iterate over list or a string variable variable in jinja template file template.conf.j2 like did with :

{% for conf_line in conf_list %}
{{conf_line}}
{% endfor %}

you could just enter insert new line signs while generating string in defaults/main.yml:

conf_list: "{%for ip in ip_list%}server {{ip}}:6666\n{%endfor%}"

and then just insert that whole string into a template.conf.j2 like this:

{{conf_line}}

nevertheless i have no other idea how to generate list of ip addresses other than the one Konstantin proposed.

Creating list of ip's in ansible using given range within jinja template

2 Answers2