op-mode: T6580: read active nodes directly from the config tree without calling cli-shell-api

[dmbaturin]

Change Summary

For op mode completion purposes, we only need to care about nodes in the active config, so none of the complexities of config sessions apply. In the current implementation that uses a directory tree for the config tree, that's equivalent to ls.

The task is made easier by the fact that op mode template interpreter doesn't care about exit codes, so even if ls exits with a non-zero code on non-existent dirs, that has no negative effects, we can just supress its error output with ls 2>/dev/null. And node names cannot contain whitespace, so we can always use them in UNIX path strings without escaping.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe): performance optimization.

Related Task(s)

Related PR(s)

Component(s) name

Op mode.

How to test

Every command that uses a node path in completion, like run show interfaces, should work as before.

Smoketest result

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

[github-actions]

👍
No issues in PR Title / Commit Title

[github-actions]

👍
No issues in unused-imports

[github-actions]

CI integration ❌ failed!

Details

CI logs

• CLI Smoketests ❌ failed
• Config tests 👍 passed
• RAID1 tests 👍 passed