"when" and "with_items" again, with a twist

[henrique....@reevoo.com]

Hi,

I'm getting an error when using "when" and "with_items" together. As I've read many times, this happens because "when" runs inside "with_items", so we can use "| default([])" to bypass the error, but I think I found a new twist on it. Here's an example:

$ cat example.yml
---
- hosts: localhost
  vars:
    run: true
  tasks:
    - block:
      - uri:
          url: "http://httpbin.org/get"
        register: example

      - debug:
          msg: "{{ example }}"

      - debug:
          msg: "{{ item }}"
        with_items: "{{ example.json | default([]) }}"

      - debug:
          msg: "{{ item }}"
        with_items: "{{ example.json.url | default([]) }}"
      when: "{{ run }}"

Let's run it twice, when "run" is set to "true" and when is it set to "false":

$ ansible-playbook example.yml -e run=true

PLAY [localhost] ***************************************************************

TASK [setup] *******************************************************************
ok: [localhost]

TASK [uri] *********************************************************************
ok: [localhost]

TASK [debug] *******************************************************************
ok: [localhost] => {
    "msg": {
        "access_control_allow_credentials": "true",
        "access_control_allow_origin": "*",
        "changed": false,
        "connection": "close",
        "content_length": "238",
        "content_type": "application/json",
        "date": "Fri, 24 Jun 2016 16:27:38 GMT",
        "json": {
            "args": {},
            "headers": {
                "Accept-Encoding": "identity",
                "Cache-Control": "no-cache",
                "Host": "httpbin.org",
                "User-Agent": "ansible-httpget"
            },
            "origin": "31.221.70.170",
            "url": "http://httpbin.org/get"
        },
        "msg": "OK (238 bytes)",
        "redirected": false,
        "server": "nginx",
        "status": 200,
        "url": "http://httpbin.org/get"
    }
}

TASK [debug] *******************************************************************
ok: [localhost] => (item=origin) => {
    "item": "origin",
    "msg": "origin"
}
ok: [localhost] => (item=headers) => {
    "item": "headers",
    "msg": "headers"
}
ok: [localhost] => (item=args) => {
    "item": "args",
    "msg": "args"
}
ok: [localhost] => (item=url) => {
    "item": "url",
    "msg": "url"
}

TASK [debug] *******************************************************************
ok: [localhost] => (item=http://httpbin.org/get) => {
    "item": "http://httpbin.org/get",
    "msg": "http://httpbin.org/get"
}

PLAY RECAP *********************************************************************
localhost                  : ok=5    changed=0    unreachable=0    failed=0

$ ansible-playbook example.yml -e run=false

PLAY [localhost] ***************************************************************

TASK [setup] *******************************************************************
ok: [localhost]

TASK [uri] *********************************************************************
skipping: [localhost]

TASK [debug] *******************************************************************
skipping: [localhost]

TASK [debug] *******************************************************************

TASK [debug] *******************************************************************
[DEPRECATION WARNING]: Skipping task due to undefined Error, in the future this will be a fatal error.: 'dict object' has no attribute 'json'.
This feature will be removed in a
future release. Deprecation warnings can be disabled by setting deprecation_warnings=False in ansible.cfg.
skipping: [localhost]

PLAY RECAP *********************************************************************
localhost                  : ok=1    changed=0    unreachable=0    failed=0

So it seems like the "| default([])" workaround doesn't work when you go one level deeper. I can understand the error, of course the attribute 'json' doesn't exist, but what other workaround could I use in this case? I've tried an ugly ternary operator to no avail:

        with_items: "{{ example.json is defined | ternary(example.json.url | default([]), []) }}"

Thank you,
Henrique Rodrigues

[Barry Kaplan]

Anybody figure out to get around these deprecation warnings?

[Brian Coca]

default only applies to the 'last' item, so if you are going to do
several depths of var defintion that can be undefined, you should have
several defaults.

"{{ (example.json|default({})).url | default([]) }}"


----------
Brian Coca

[Barry Kaplan]

Thanks Brian. Just saw that example in another post. It does work of course, but boy is it ugly.