custom lookup plugin found with ansible-doc but not found in playbook

[philbert]

SUMMARY

Custom lookup plugin appears correctly configured using ansible-doc -t lookup listFolders however always results in FAILED! => {"msg": "lookup plugin (listFolders) not found"} when used in playbook.

ISSUE TYPE

• Bug Report

COMPONENT NAME

• Custom lookup plugin

ANSIBLE VERSION

ansible 2.9.2
  config file = /Users/xxxx/.ansible.cfg
  configured module search path = ['/Users/xxxx/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/Cellar/ansible/2.9.2_1/libexec/lib/python3.8/site-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.8.1 (default, Dec 27 2019, 18:05:45) [Clang 11.0.0 (clang-1100.0.33.16)]

CONFIGURATION

defaults only

OS / ENVIRONMENT

• macOS Mojave 10.14.6
• zsh 5.3 (x86_64-apple-darwin18.0)

STEPS TO REPRODUCE

Here is a trivial custom lookup plugin that just contains documentation to test my configuration.
It is placed in /Users/xxxx/.ansible/plugins/lookup/listFolders.py

DOCUMENTATION = """
    lookup: listFolders
    short_description: returns list from yaml descriptor
    description:
        - This lookup returns a list from the yaml descriptor
"""

This command correctly pics up the lookup plugin:
ansible-doc -t lookup listFolders

And shows the output:

> LISTFOLDERS    (/Users/xxxx/.ansible/plugins/lookup/listFolders.py)

        This lookup returns a list from the yaml descriptor

  * This module is maintained by The Ansible Community
        METADATA:
          status:
          - preview
          supported_by: community

However in a playbook I always hit this error:
fatal: [localhost]: FAILED! => {"msg": "lookup plugin (listFolders) not found"}

Here is a sample playbook that produces the error:

---
- name: "Test custom lookup plugin"
  hosts: localhost
  tasks:
    - name: lookup listFolders
      debug:
        msg: '{{ lookup("listFolders") }}'

EXPECTED RESULTS

TASK [lookup listFolders] ***************************************************************************************************************************************************************
ok: [localhost]

ACTUAL RESULTS

TASK [lookup listFolders] ***************************************************************************************************************************************************************
fatal: [localhost]: FAILED! => {"msg": "lookup plugin (listFolders) not found"}

> ansible-playbook testplaybook.yml 

[WARNING]: No inventory was parsed, only implicit localhost is available

[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'


PLAY [Test custom lookup plugin] ************************************************************************************************************************

TASK [Gathering Facts] ******************************************************************************************************************************************************************
ok: [localhost]

TASK [lookup listFolders] ***************************************************************************************************************************************************************
fatal: [localhost]: FAILED! => {"msg": "lookup plugin (listFolders) not found"}

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

[ansibot]

Files identified in the description:

• lib/ansible/plugins/lookup

If these files are inaccurate, please update the component name section of the description or use the !component bot command.

click here for bot help

[mkrizek]

Doing with_listFolders: finds the lookup plugin correctly (of course failing then with The error was: AttributeError: module 'ansible.plugins.lookup.listFolders' has no attribute 'LookupModule').

For "{{ lookup("listFolders", ...) }}", loading the plugin appears to be case sensitive. The following change will make the loader find the plugin:

diff --git a/lib/ansible/template/__init__.py b/lib/ansible/template/__init__.py
index 062c4d6889..7cea02bc77 100644
--- a/lib/ansible/template/__init__.py
+++ b/lib/ansible/template/__init__.py
@@ -749,7 +749,7 @@ class Templar:
         return self._lookup(name, *args, **kwargs)
 
     def _lookup(self, name, *args, **kwargs):
-        instance = self._lookup_loader.get(name.lower(), loader=self._loader, templar=self)
+        instance = self._lookup_loader.get(name, loader=self._loader, templar=self)
 
         if instance is not None:
             wantlist = kwargs.pop('wantlist', False)

Having said that I am not sure as to why the behavior is different for each of the above or if it is intended.

[philbert]

Yes, it was a case sensitivity issue. I confirmed that changing the file name to listfolders.py allowed my playbook to pick up the plugin correctly.

It looks to me that your fix would bring consistency to all 3 functions: with_*, lookup() and ansible-doc?

Thanks for the quick response!

[bcoca]

all 3 should be case sensitive, seems with_ lookup is not.