KeyError Tag: docker 29 incompatibility

[Obyka]

ISSUE TYPE

• Bug Report

SUMMARY

ansible-navigator images fails with KeyError: 'tag' when using Docker 29.x due to JSON output schema changes in docker images --format json.

Docker 29 returns capitalized JSON keys (e.g. "Tag"), while ansible-navigator 26.1.2 expects lowercase keys (e.g. "tag"), causing a crash during image inspection.

ANSIBLE-NAVIGATOR VERSION

"ansible-navigator 26.1.2"

CONFIGURATION

No custom ansible-navigator.yaml present.

Container engine: docker (default)

LOG FILE

CRITICAL 'ansible_navigator.actions._actions.run_interactive' Subcommand 'images' encountered a fatal error.
ERROR 'ansible_navigator.actions._actions.run_interactive' Logging an uncaught exception
Traceback (most recent call last):
  File ".../ansible_navigator/actions/_actions.py", line 202, in run_interactive
    return run_action(app=app, interaction=interaction)
  File ".../ansible_navigator/actions/images.py", line 240, in run
    self._collect_image_list()
  File ".../ansible_navigator/actions/images.py", line 457, in _collect_image_list
    images, error = inspect_all(container_engine=self._args.container_engine)
  File ".../ansible_navigator/image_manager/inspector.py", line 115, in inspect_all
    result = cmd_runner.run_single_process(commands=images_list_class.commands)
  File ".../ansible_navigator/command_runner/command_runner.py", line 124, in run_single_process
    command.post_process(command)
  File ".../ansible_navigator/image_manager/inspector.py", line 97, in parse
    valid_images = [image for image in local_images if image["tag"] != "<none>"]
  File ".../ansible_navigator/image_manager/inspector.py", line 97, in <listcomp>
    valid_images = [image for image in local_images if image["tag"] != "<none>"]
KeyError: 'tag'

STEPS TO REPRODUCE

1. Install Docker 29.x
2. Install ansible-navigator 26.1.2 via pip or pipx.
3. Run ansible-navigator images

EXPECTED RESULTS

ansible-navigator images should list local container images without crashing, regardless of Docker JSON field capitalization changes.

ACTUAL RESULTS

The command crashes with:

KeyError: 'tag'

ADDITIONAL INFORMATION

Docker version 29.0.4, build 3247a5a

docker images --format json | head -n 1
{"Containers":"1","CreatedAt":"2026-02-16 08:07:02 +0100 CET","CreatedSince":"31 hours ago","Digest":"<none>","ID":"1ef93f0d9e75","Repository":"ddev/ddev-webserver","SharedSize":"N/A","Size":"1.27GB","Tag":"v1.24.10-efficare-built","UniqueSize":"N/A"}

Suggested fix: normalize keys (case-insensitive lookup) or explicitly handle both "tag" and "Tag" when parsing Docker image output.