# Templates & looping on json data structure **URL:** \ **Category:** Ansible Project\ **Created:** [October 24, 2013, 9:19am UTC](https://forum.ansible.com/t/templates-looping-on-json-data-structure/13760 "2013-10-24T09:19:53Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Smain\_Kahlouch](https://avatars.discourse-cdn.com/v4/letter/s/ee59a6/32.png) [@Smain\_Kahlouch](https://forum.ansible.com/u/Smain_Kahlouch)\ **Post date:** [October 24, 2013, 9:19am UTC](https://forum.ansible.com/t/templates-looping-on-json-data-structure/13760/1 "2013-10-24T09:19:53Z")
Hello, I have a data structure gathered from a postgres db (external inventory) with a list of json data structures as follows : [ {‘name’: conf1, ‘myvar1’: 1, ‘myvar2’: blabla}, {‘name’: conf2, ‘myvar1’: 44, ‘myvar2’: hello} ] And i would like to use a kind of loop to create a file like : [conf1] param1 = 1 param2 = blabla [conf2] param1 = 44 param2 = hello I’ve read in the ansible " ansible allows Jinja2 loops and conditionals in templates, but in playbooks, we do not use them. Ansible templates are pure machine-parseable YAML. This is an rather important feature as it means it is possible to code-generate pieces of files, or to have other ecosystem tools read Ansible files. Not everyone will need this but it can unlock possibilities. " Is there a way to perform that kind of loops please ? Regards, Smana ---
**Author:** ![Smain\_Kahlouch](https://avatars.discourse-cdn.com/v4/letter/s/ee59a6/32.png) [@Smain\_Kahlouch](https://forum.ansible.com/u/Smain_Kahlouch)\ **Post date:** [October 24, 2013, 1:58pm UTC](https://forum.ansible.com/t/templates-looping-on-json-data-structure/13760/2 "2013-10-24T13:58:31Z")
my current script generates this output : { “databases”: { “hosts”: , “vars”: {} }, “webservers”: { “hosts”: [ “10.18.2.1”, “10.18.2.2”, ], “vars”: {} }, “Site”: { “children”: [ “databases”, “webservers” ], “vars”: [ { “id”: 4912, “path”: “test1.mp3”, } { “id”: 4913, “path”: “test2.mp3”, } ] } } But i got this error when executing ansible : /etc/ansible/services/mysite 0 # ansible all -i ./inventory.py Traceback (most recent call last): File “/usr/bin/ansible”, line 157, in (runner, results) = cli.run(options, args) File “/usr/bin/ansible”, line 79, in run inventory\_manager = inventory.Inventory(options.inventory) File “/usr/lib/python2.7/dist-packages/ansible/inventory/ **init**.py”, line 101, in **init** self.parser = InventoryScript(filename=host\_list) File “/usr/lib/python2.7/dist-packages/ansible/inventory/script.py”, line 47, in **init** self.groups = self.\_parse(stderr) File “/usr/lib/python2.7/dist-packages/ansible/inventory/script.py”, line 92, in \_parse for k, v in data[‘vars’].iteritems(): AttributeError: ‘list’ object has no attribute ‘iteritems’ I need to iterate on a list of several variables. Do you think that’s possible ? Regards, Smana ---
**Author:** ![Smain\_Kahlouch](https://avatars.discourse-cdn.com/v4/letter/s/ee59a6/32.png) [@Smain\_Kahlouch](https://forum.ansible.com/u/Smain_Kahlouch)\ **Post date:** [October 25, 2013, 11:11am UTC](https://forum.ansible.com/t/templates-looping-on-json-data-structure/13760/3 "2013-10-25T11:11:30Z")
Any idea please ? Regards, Smana ---
**Author:** ![Kesten\_Broughton2](https://avatars.discourse-cdn.com/v4/letter/k/ecc23a/32.png) [@Kesten\_Broughton2](https://forum.ansible.com/u/Kesten_Broughton2)\ **Post date:** [October 25, 2013, 5:03pm UTC](https://forum.ansible.com/t/templates-looping-on-json-data-structure/13760/4 "2013-10-25T17:03:54Z")
Smain, Although full jinja2 templating is not available in tasks/playbooks, other features like pipes/filters are.Try piping your datastructure with to\_json like - name: do a thing copy: src=“{{item}}” dest=/foo with\_items: {{output | to\_json}} I used something like this as well, where \_requested\_hosts was a dict passed in to a task like [main.yml] - include: { playbook.yml, \_requested\_hosts: {{some\_dict\_defined\_in\_vars\_main.yml}} } [playbook.yml] - debug: msg=“{{\_requested\_hosts | to\_json | capture(requested\_hosts)}}” The problem is that passing structures between playbook files seems to serialize it, and this deserializes it. kesten ---
**Author:** ![Michael\_DeHaan2](https://avatars.discourse-cdn.com/v4/letter/m/da6949/32.png) [@Michael\_DeHaan2](https://forum.ansible.com/u/Michael_DeHaan2)\ **Post date:** [October 25, 2013, 11:49pm UTC](https://forum.ansible.com/t/templates-looping-on-json-data-structure/13760/5 "2013-10-25T23:49:02Z")
I don’t endorse the above suggestion by Kesten, and I’m pretty sure it’s not going to work 🙂 You have a list data structure so iteritems isn’t a method on a list. If you just want to generate the config file I would do this as a template module: (WARNING: untested general idea) {% for entry in foo %} {% for (k,v) in entry.iteritems() %} {% if k == ‘name’ %} [{{ v }}] {% endif %} {% endfor %} {% for (k,v) in entry.iteritems() %} {% if k != ‘name’ %} {{ k }}={{ v }} {% endif %} {% endfor %} {% endfor %} - template: src=foo.j2 dest=wherever.out Note that I’m answering your first question and not your second – your variable structures are different in each. ---
**Author:** ![Smain\_Kahlouch](https://avatars.discourse-cdn.com/v4/letter/s/ee59a6/32.png) [@Smain\_Kahlouch](https://forum.ansible.com/u/Smain_Kahlouch)\ **Post date:** [October 29, 2013, 9:06am UTC](https://forum.ansible.com/t/templates-looping-on-json-data-structure/13760/6 "2013-10-29T09:06:29Z")
Hello all, For information i managed to do what i wanted. i just changed my list into a dictionnary : mylist = [{‘name’: conf1, ‘myvar1’: 1, ‘myvar2’: blabla}, {‘name’: conf2, ‘myvar1’: 44, ‘myvar2’: hello}] mydict = { mylist } then i used this dictionnary in my playbook as follows : - name: foo configuration template: src=foo.cfg dest=/etc/foo/{{ item[‘name’] }}.sh with\_items: $mydict the “item” variable can also be use inside the template. Thanks for your help. Regards ---
**Author:** ![Michael\_DeHaan2](https://avatars.discourse-cdn.com/v4/letter/m/da6949/32.png) [@Michael\_DeHaan2](https://forum.ansible.com/u/Michael_DeHaan2)\ **Post date:** [October 30, 2013, 1:50am UTC](https://forum.ansible.com/t/templates-looping-on-json-data-structure/13760/7 "2013-10-30T01:50:44Z")
No need for the legacy variable here, BTW, just do this: with\_items: mydict