feat(host_sysctl): add host sysctl collector

[JGAntunes]

Description, Motivation and Context

Fixes - #1674

Checklist

• New and existing tests pass locally with introduced changes.
• Tests for the changes have been added (for bug fixes / features)
• The commit message(s) are informative and highlight any breaking changes
• Any documentation required has been added/updated. For changes to https://troubleshoot.sh/ create a PR here - feat(host_sysctl): add doc entry for a host sysctl collector and analyzer troubleshoot.sh#592

Does this PR introduce a breaking change?

• Yes
• No

[CLAassistant]

All committers have signed the CLA.

[JGAntunes]

@banjoh I've re-implemented the collector using - https://github.com/lorenzosaino/go-sysctl - let me know what you think. I've regenerated the schemas and tested out the collector but for wtv reason it isn't picking up on it 🤔 :

sudo bin/support-bundle -v 5 examples/collect/host/sysctl.yaml
I1107 11:30:15.363160   21229 loader.go:261] Loaded 1 troubleshoot specs successfully

I1107 11:30:15.363755   21229 supportbundle.go:80] Support bundle created in temporary directory: /tmp/supportbundle1604379718

============ Collectors summary =============
Succeeded (S), eXcluded (X), Failed (F)
=============================================
No collectors executed

============ Redactors summary =============
No redactors executed

============= Analyzers summary =============
Succeeded (S), eXcluded (X), Failed (F)
=============================================
No analyzers executed

Duration: 0ms
Error: failed to run collect and analyze process: failed to generate support bundle

I'm gonna follow up and try to get to the bottom of it after lunch but meanwhile if you have any leads let me know

[banjoh]

There is an error here

E1107 12:10:03.235230   56942 host_sysctl.go:39] Failed to initialize sysctl client: could not create client: directory /proc/sys/ does not exist

I think we should revert back to calling sysctl instead of relying on a library, otherwise we need to handle those rare environments, e.g darwin that don't have /proc/sys.

[JGAntunes]

Hmm yeah true, darwin won't have procfs, however the props will be completely different too and even the output will differ between sysctl -a in darwin vs linux. But agree it's probably the best approach out of both options. Gonna go back to that and have a common output from the collector

[JGAntunes]

Done, let me know what you think @banjoh

[JGAntunes]

Running this locally:

sudo bin/support-bundle -v 5 examples/collect/host/sysctl.yaml
Password:
Sorry, try again.
Password:
I1107 17:36:46.636143   22606 loader.go:261] Loaded 1 troubleshoot specs successfully

I1107 17:36:46.638142   22606 supportbundle.go:80] Support bundle created in temporary directory: /tmp/supportbundle3644184749
I1107 17:36:46.638421   22606 host_sysctl.go:37] Running sysctl collector
I1107 17:36:46.660001   22606 result.go:138] Added "host-collectors/system/sysctl.json" (61 KB) to bundle output
I1107 17:36:46.660079   22606 host_sysctl.go:58] Finished writing JSON output
I1107 17:36:46.660284   22606 redact.go:76] Redacting host-collectors/system/sysctl.json
I1107 17:36:46.676436   22606 result.go:138] Added "version.yaml" (0 KB) to bundle output
I1107 17:36:46.676641   22606 result.go:138] Added "analysis.json" (0 KB) to bundle output
I1107 17:36:46.676875   22606 result.go:138] Added "execution-data/summary.txt" (0 KB) to bundle output
I1107 17:36:46.678857   22606 result.go:364] Added "support-bundle-2024-11-07T17_36_46/host-collectors/system/sysctl.json" file to bundle archive
I1107 17:36:46.679426   22606 result.go:364] Added "support-bundle-2024-11-07T17_36_46/version.yaml" file to bundle archive
I1107 17:36:46.679456   22606 result.go:364] Added "support-bundle-2024-11-07T17_36_46/analysis.json" file to bundle archive
I1107 17:36:46.679501   22606 result.go:364] Added "support-bundle-2024-11-07T17_36_46/execution-data/summary.txt" file to bundle archive

A support bundle was generated and saved at support-bundle-2024-11-07T17_36_46.tar.gz. Please send this file to your software vendor for support.

============ Collectors summary =============
Succeeded (S), eXcluded (X), Failed (F)
=============================================
sysctl (S) : 21ms

============ Redactors summary =============
No redactors executed

============= Analyzers summary =============
Succeeded (S), eXcluded (X), Failed (F)
=============================================
No analyzers executed

Duration: 38ms

The file

cat support-bundle-2024-11-07T17_36_46/host-collectors/system/sysctl.json | jq . | less

{
  "debug.batman": "3",
  "debug.bpf_bufsize": "4096",
  "debug.bpf_bufsize_cap": "33554432",
  "debug.bpf_debug": "0",
  "debug.bpf_hdr_comp_enable": "1",
  "debug.bpf_maxbufsize": "524288",
  "debug.bpf_maxdevices": "256",
  "debug.bpf_trunc_overflow": "0",
  "debug.bpf_wantpktap": "0",
  "debug.didevice_bounce_count": "0",
  "debug.didevice_cache_fully_satisfied": "0",
  (...)
   "hw.cacheconfig": "16 1 4 0 0 0 0 0 0 0",
  "hw.cachelinesize": "128",
  "hw.cachesize": "3077505024 65536 4194304 0 0 0 0 0 0 0",
  (...)
   "kern.bootobjectspath": "/A81AC697-1175-480B-BCFF-526D0CD80FAB/boot/B654B73FA61DA0731F2F0CCC0E3C9ECA7260AF38CEF42BEAB2F12DCD58F01F37F14F51EDCDDBB4393F0FDFDA2BCDBA5B",
  "kern.bootreason": "gcb_off_wakeup gcb_wakeup rtc_alarm_wakeup auto_wakeup",
  "kern.bootsessionuuid": "844BD71A-07AB-42D3-8BF7-68309DF07CD3",
  "kern.bootsignature": "",
  "kern.boottime": "{ sec = 1729157179, usec = 466869 } Thu Oct 17 10:26:19 2024",
  (...)
}

[banjoh]

LGTM