Compare Strings to get Unique values in Jinja2

I have a variable with list of node IP's and its respective Availability Zone.

seed = {
  10.18.13.12 = us-east-1a
  10.18.37.93 = us-east-1b
  10.18.68.147 = us-east-1a
  10.18.21.55 = us-east-1b
}

I will be using this variable in Jinja template but want to filter out the variable based on unique Avalability Zones and get the IP. I want to compare the Avalability Zones to get unique values and have IP from each unique Avalability Zone. For instance I want the output in form of

"10.18.13.12, 10.18.37.93"

or

"10.18.68.147, 10.18.21.55"

Is this possible to perform such operations of comparing strings and get its respective value in Jinja template? Anything would help. Thanks in advance.

Yes, this can be done. The following should do the trick:

"{%- for ip, az in seed.iteritems() %} 
  {%- if 'us-east-1a' in az %}
    {%- if firstloop is not defined %}
    {%- set firstloop = 1 %}
{{- ip }}
    {%- else %}
{{- " " + ip}}
    {%- endif %}    
  {%- endif %}
{%- endfor%}"

To test it with https://cryptic-cliffs-32040.herokuapp.com/, you can use the following JSON:

{
    "seed": {
      "10.18.13.12": "us-east-1a",
      "10.18.37.93": "us-east-1b", 
      "10.18.68.147": "us-east-1a",
      "10.18.21.55": "us-east-1b"
    }
}

You might give the documentation a read if you are going to be doing much jinja templating. I have found it indispensible.

StackExchange DevOps Q#2906, answer score: 2