extension version without decimal causes postgresql_info exception

[phemmer]

SUMMARY

When an extension is installed that doesn't have a . in the version, the postgresql_info module throws an exception.

ISSUE TYPE

• Bug Report

COMPONENT NAME

postgresql_info

ANSIBLE VERSION

ansible 2.10.11
  config file = None
  configured module search path = ['/home/phemmer/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/phemmer/.local/lib/python3.9/site-packages/ansible
  executable location = /home/phemmer/.local/bin/ansible
  python version = 3.9.5 (default, May 14 2021, 00:00:00) [GCC 11.1.1 20210428 (Red Hat 11.1.1-1)]

COLLECTION VERSION

# /home/phemmer/.local/lib/python3.9/site-packages/ansible_collections
Collection           Version
-------------------- -------
community.postgresql 1.1.1  

CONFIGURATION

OS / ENVIRONMENT

Debian 10/Buster
PostgreSQL 13

STEPS TO REPRODUCE

1. Install an extension without a . in the version, for example pguint.

# psql mydb
mydb=> select * from pg_available_extensions where name='uint';
 name | default_version | installed_version |        comment         
------+-----------------+-------------------+------------------------
 uint | 0               |                   | unsigned integer types
(1 row)

mydb=> create extension uint;
CREATE EXTENSION

2. use postgresql_info.

ansible myhost -m postgresql_info

EXPECTED RESULTS

Works

ACTUAL RESULTS

# ansible myhost -m postgresql_info
The full traceback is:
Traceback (most recent call last):
  File "master:/home/phemmer/git/ht/edge/ansible/ht/mitogen/ansible_mitogen/runner.py", line 975, in _run
    self._run_code(code, mod)
  File "master:/home/phemmer/git/ht/edge/ansible/ht/mitogen/ansible_mitogen/runner.py", line 939, in _run_code
    exec(code, vars(mod))
  File "master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py", line 1030, in <module>
  File "master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py", line 1026, in main
  File "master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py", line 617, in collect
  File "master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py", line 973, in get_db_info
  File "master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py", line 734, in get_ext_info
IndexError: list index out of range
myhost | FAILED! => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "module_stderr": "Traceback (most recent call last):\n  File \"master:/home/phemmer/git/ht/edge/ansible/ht/mitogen/ansible_mitogen/runner.py\", line 975, in _run\n    self._run_code(code, mod)\n  File \"master:/home/phemmer/git/ht/edge/ansible/ht/mitogen/ansible_mitogen/runner.py\", line 939, in _run_code\n    exec(code, vars(mod))\n  File \"master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py\", line 1030, in <module>\n  File \"master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py\", line 1026, in main\n  File \"master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py\", line 617, in collect\n  File \"master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py\", line 973, in get_db_info\n  File \"master:/home/phemmer/.local/lib/python3.9/site-packages/ansible_collections/community/general/plugins/modules/postgresql_info.py\", line 734, in get_ext_info\nIndexError: list index out of range\n",
    "module_stdout": "",
    "msg": "MODULE FAILURE\nSee stdout/stderr for the exact error",
    "rc": 1
}

[phemmer]

This looks like it'd be trivial to fix, however there are several approaches, none of them good.

Ultimately the problem is that postgresql_info is assuming that all extension versions follow a convention containing major and minor components separated by decimal (.). This is not the case. In addition to this example which only has a single component, other plugins may have 3 or more components when split.

As such, my proposal would be either:

1. Don't split the version, leave it as a string.
2. Split and return as an array.

I think # 1 is the safer option. If people really need it split, they can split it themselves.
However both options are breaking changes.

[Andersson007]

@phemmer hello, thank you for reporting this and welcome to the project!

I'll take a closer look tomorrow.

Quick thoughts:

1. we can check the length after splitting and handle this case properly, e.g. put None to minor part.
2. in any case we can add a parameter called raw to return versions as they are. It wouldn't be a breaking change

If you want to fix this, we have a quick start guide to help newcomers, here it is https://github.com/ansible/community-docs/blob/main/create_pr_quick_start_guide.rst. What do you think? Feel free to raise a PR

[Andersson007]

@phemmer after evaluating things, could you please put it in here explicitly if you have time to fix this or not (to avoid working in parallel). Thank you:)

[phemmer]

Sorry for delay, I doubt I'll have time to fix and submit a PR. But will let you know if that changes.

[Andersson007]

@phemmer no problem! Thanks for the feedback. OK, if anyone wants, feel free to pick it up (put your intention explicitly in here).

[Andersson007]

I'm looking (btw it's not as easy as i thought)

[Andersson007]

#138