feat: add ceph, rados, rbd, ceph-volume and radosgw-admin commands

[AlexonOliveiraRH]

Summary

• Add support for displaying pre-captured Ceph command outputs from ODF (OpenShift Data Foundation) must-gather archives
• New commands: omc ceph, omc rados, omc rbd, omc ceph-volume, omc radosgw-admin
• Dynamic passthrough approach - all 80+ captured Ceph commands are automatically accessible without hardcoded mappings
• JSON output support via --output json-pretty flag
• Suggestions for available commands when the requested output is not found

Closes #248

Motivation

The ODF must-gather already collects Ceph CLI outputs as files under ceph/must_gather_commands/ and ceph/must_gather_commands_json_output/, but omc had no way to access them. Users had to manually navigate the must-gather directory structure.

This feature was inspired by a similar implementation in o-must-gather (omg) v2 branch, which was never officially released (last release v1.2.6, April 2021; project dormant since February 2024). Since omc is the actively maintained tool, this brings the functionality here with an improved approach - dynamic argument-to-filename mapping instead of the limited set of commands omg v2 supported.

How it works

Arguments are converted to filenames matching the must-gather naming convention:

• omc ceph status -> reads ceph/must_gather_commands/ceph_status
• omc ceph osd tree -> reads ceph/must_gather_commands/ceph_osd_tree
• omc ceph status --output json-pretty -> reads ceph/must_gather_commands_json_output/ceph_status_--format_json-pretty
• omc ceph config show osd.0 -> reads ceph/must_gather_commands/config_osd.0 (special case for ODF naming)

When the output file is not found, available commands matching the prefix are listed as suggestions.

Files changed

File	Description
cmd/ceph/lookup.go	Shared logic: filename construction, arg parsing, file lookup, suggestions
cmd/ceph/ceph.go	omc ceph command
cmd/ceph/rados.go	omc rados command
cmd/ceph/rbd.go	omc rbd command
cmd/ceph/cephvolume.go	omc ceph-volume command
cmd/ceph/radosgwadmin.go	omc radosgw-admin command
cmd/ceph/lookup_test.go	Tests (7 test functions covering all logic)
root/root.go	Register new commands

Test plan

• go build -v ./... passes
• go test -v ./... passes (all existing + 7 new tests)
• Tested manually against a real ODF must-gather (case 04432224):
  • omc ceph status - cluster status output
  • omc ceph osd tree - OSD tree
  • omc ceph status --output json-pretty - JSON output
  • omc ceph config show osd.0 - OSD config (special case)
  • omc rados lspools - pool listing
  • omc rbd ls <pool> - RBD volume listing
  • omc ceph-volume raw list - volume raw list
  • omc radosgw-admin realm list - RGW realm listing
  • omc ceph nonexistent - error with no suggestions
  • omc ceph osd - error with matching suggestions
  • omc ceph / omc ceph --help - help output
  • No regressions in existing commands