Let's say I have the following Jinja2 variables:
'dev_ami' = 'ami-123456'
'dev_located_ami' = 'ami-123456'
'prod_ami' = 'ami-654321'
'prod_located_ami' = 'ami-654321'
I would like to set a condition upon when the 'dev_ami' variable is equal to the 'dev_located_ami' variable. This would easily be done as shown in the following statement:
{% if dev_ami == dev_located_ami %}
... do some stuff
{% else %}
... do some other stuff
{% endif %}
But I would like to dynamically compare amis based on the deployment environment contained in a list ['dev','prod', etc...]. The following contains a templating error since there is an expression within a statement as such - {% {{ .. }} %}:
{% for env_type in ['dev','prod'] %}
{% if {{ env_type }}_ami == {{ env_type }}_located_ami %}
... do stuff
{% else %}
... do other stuff
{% endif %}
{% endfor %}
I have tried to set variables to represent the expressions I would like in the following code but unfortunately they are compiled literally as 'dev_ami' and 'dev_located_ami' whereas I would like them compiled to their corresponding variable values 'ami-123456' and 'ami-123456':
{% for env_type in ['dev','prod'] %}
{% set ami = "%s_ami"|format(env_type) %}
{% set located_ami = "%s_located_ami"|format(env_type) %}
{% if ami == located_ami %}
... do stuff
{% else %}
... do other stuff
{% endif %}
{% endfor %}
I have checked through various filters and so far have had no success. Would appreciate advice on getting this specific implementation to work properly. Thank you in advance.
I think you might be approaching the problem with the wrong datastructure in mind.
Dynamically generating variable names in order to compare amis in different environemts sounds like a massive overkill to me. Are you familiar with lists & dictionaries?
Try to start from something like this (pseudocode):
dict = { environments:
prod:
ami1: foo
ami1_located: foo
dev:
ami1: bar
ami1_located:baz
}
for env in dict[environments]:
if env[ami1] == env[ami1_located]:
[...]
Related
I want to use the n values in the next for statement and I expect output as router_0, router_1. But any optisons like router_[n], router_{{ n }}, router_(n) etc didnt work. How can we do this?
{% for n in range(0, 2) %}
{% for rtr in web.router_[n] %}
{% if rtr.interface.type == 'lacp' %}
interface Port-Channel{{ rtr.interface.id }}
.
{% endif %}
{% endfor %}
{% endfor %}
In vars.yaml, there are variables for paired routers, router_0 and router_1. I want to generate the config template for both routers at the same time.
Thanks,
Concatenate the name of the attribute
{% for rtr in web['router_' ~ n] %}
Basically I try to combine multiple conditions in a for loop. For two conditions its working fine
{% for blockName in (userblocks if sitename == "user" else xpertBlocks) %}
but is there also a way, to realize three or more conditions in a for loop, like so:
{% for blockName in (userBlocks if sitename == "user" elif sitename == "xpert" xpertBlocks else "provider") %}
I couldn't find anything in the nunjucks documentation.
{% set chooser = {user: userBlocks, xpert: xpertBlocks, ...} %}
{% set blocks = chooser[sitename] or providerBlocks %}
{% for blockName in blocks %}
...
{% endfor %}
I have the below jinja code to conditionally concatenate strings depending on two variables. Whilst it (probably) works it looks unwieldy, but I'd have thought this was a common thing to do when rendering.
{% if item.route %}
{% if item.route_follow and item.route_external %} {% set route_rel = 'external' %}
{% elif not item.route_follow and not item.route_external %} {% set route_rel = 'nofollow' %}
{% elif not item.route_follow and item.route_external %} {% set route_rel = 'nofollow external' %}
{% else %} {% set route_rel = '' %}
{% endif %}
{% endif %}
Is there a better way, maybe a one-liner?
When I got to the end of this I realised the answer:
{% if item.route %}
{% set route_rel = ['' if item.route_follow else 'nofollow', 'external' if item.route_external else '']|reject('==','')|join(' ') %}
{% endif %}
Sometimes, you just have to look at it again...
I am trying to generate some config using Jinja2 templating and Ansible variables. The framework under which I am currently working does not allow me to perform the following operation in Ansible and thus I was hoping to achieve the same results in Jinja2.
My Ansible variables are as follows:
---
Top:
inner:
type: type1
other_random_variable:
- random: 1
inner2:
type: type2
inner3:
type: type1
The above structure works well when I am iterating over a loop and forming a configuration file as follows:
{% if Top is defined %}
{% for inner_vars in Top %}
# perform substitution here
{% endfor %}
{% endif %}
What I would like to do is to form a set of types such that I can generate another configuration for each unique type.
Is there any way for me to iterate through Top and add an item to a set?
I think I have a solution that could work:
{% set types = [] %}
{% if Top is defined%}
{% for inner_var in Top %}
{% if types.append(Top[inner_var].type) %}{% endif %}
{% endfor %}
{% endif %}
{{ types|unique }}
I was wondering what is the proper way of finding the index of an item in an array is in a Liquid template, and selected related items based off of the index. Currently I'm able to calculate the value, but it seems to be a string and I can't then find other items in the array with the string. For example in a CMS:
{% for site_page in site.pages.all %}
{% if site_page.id == page.id %}
{% assign page_index = forloop.index0 %}
{% capture previous_page_index %}
{{ page_index | minus: 1 }}
{% endcapture %}
{% break %}
{% endif %}
{% endfor %}
The expected value can be found in previous_page_index (in this case 0) however, if i try to do something like site.pages.all[previous_page_index] I receive no output. If I do the same thing with a hardcoded index value: site.pages.all[0] it does yield an output. Does anyone have an idea/example on how this is supposed to be done in liquid?
Best I can figure is to use {% for item in array limit:1 offset:forloop.index0 %}. For example:
require 'liquid'
chars = %w[a b c]
names = %w[alpha bravo charlie]
puts Liquid::Template.parse(<<DONE).render( 'chars'=>chars, 'names'=>names )
{% for c in chars %}
{{c}} is
{% for n in names limit:1 offset:forloop.index0 %}{{n}}{% endfor %}
{% endfor %}
DONE
…which produces…
a is
alpha
b is
bravo
c is
charlie
Editorial aside: ouch. What an ugly tempting language. I understand its goals, but the burden it places on users is heinous.