5gc core install.yml: missing-deps error task fails with template error when find is skipped

[bengrewell]

Summary

When core.helm.local_charts: true is set AND the component chart under /tmp/sdcore-helm-charts/5g-control-plane/ has no charts/ subdirectory (i.e. helm dep up has never been run), the task at deps/5gc/roles/core/tasks/install.yml:170 (require manual 5gc-cp helm dependency update when charts are missing) fails with a cryptic Jinja error instead of the intended "missing deps" message.

Reproduce

1. Clone a fresh sdcore-helm-charts into the configured local_sd_core_chart_root.
2. Do NOT run helm dep up — leave 5g-control-plane/charts/ absent.
3. Set core.helm.local_charts: true and core.helm.chart_ref: <local-path> in vars/main.yml.
4. Run make aether-5gc-install.

Observed behaviour

TASK [core : check local 5gc-cp chart dependencies] ***
skipping: [localhost] => (item=mongodb)
skipping: [localhost] => (item=kafka)
skipping: [localhost]

TASK [core : require manual 5gc-cp helm dependency update when charts are missing] ***
fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'dict object' has no attribute 'matched'. 'dict object' has no attribute 'matched'\n\nThe error appears to be in 'deps/5gc/roles/core/tasks/install.yml': line 170, column 3..."}

Root cause

Preceding task at line 157 (check local 5gc-cp chart dependencies, a find with loop: core_cp_dependency_names) has when: core_cp_charts_dir.stat.exists. When charts/ does not exist, every loop iteration is skipped. The register (core_cp_chart_dependencies) ends up as a dict with a results list of skipped-loop-item dicts — each lacks the matched field that a successful find populates.

The next task (install.yml:170) then evaluates:

core_cp_chart_dependencies.results | default([]) | selectattr('matched', 'equalto', 0) | list | length

selectattr('matched', ...) blows up evaluating the skipped-item dicts because matched is absent. The not core_cp_charts_dir.stat.exists short-circuit in the surrounding or doesn't save us because Jinja eagerly evaluates both operands.

Proposed fix

Guard the selectattr so it only runs over items that actually have a matched key (i.e. non-skipped find results). One option:

when:
  - inventory_hostname in groups['master_nodes']
  - core.helm.local_charts
  - >
    not core_cp_charts_dir.stat.exists
    or (core_cp_chart_dependencies.results | default([])
        | rejectattr('skipped', 'defined')
        | selectattr('matched', 'equalto', 0)
        | list | length) > 0

Same rejectattr('skipped', 'defined') should be applied to the msg: expression a few lines above (which has the same filter chain and will also throw if reached under similar conditions).

Workaround

Pre-populate each component chart's charts/ subdir at bundle/build time via helm dep up, so the find task has something to iterate and the skipped-item branch is never hit. This is what aether-ops-bootstrap (downstream) is now doing to unblock its airgap flow.

Context

Surfaced while moving an aether-ops / aether-onramp deploy to fully-airgap operation. Happy to open a PR with the rejectattr('skipped', 'defined') fix if helpful.