feat: add output format flag to the k0s sysinfo command

[emosbaugh]

Description

Adds --output flag to the sysinfo command with formats human|yaml|json.

sysinfo.json

Fixes # (issue)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

• Manual test
• Auto test added

Checklist:

• My code follows the style guidelines of this project
• My commit messages are signed-off
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

[twz123]

Ha, wanted to do this since its inception ^^

The initial idea was to have a separate JSON reporter for this, though.

[emosbaugh]

Ha, wanted to do this since its inception ^^

The initial idea was to have a separate JSON reporter for this, though.

@twz123 Could you provide some feedback on the Probe struct? After that I'm happy to refactor.

[twz123]

Not sure about the JOSN/YAML structure. Did you consider to model the sysinfo hierarchy into the output structure? Alternatively, have the paths be the keys in a big map (urgh, there's no way to keep the order of things in there, right? :-( )? I'd also use camelCase for the keys, and omit empty fields. I'm pondering about a "somewhat natural" jq/jsonpointer expression to select individual probes 🤔

[twz123]

What I had in mind:

• Leave the cliReporter unmodified.
• Just have the resultsCollector to collect the tree.

Have the switch statement in the command look like this:

switch outputFormat {
case "human":
	cli := &cliReporter{
		w:      out,
		colors: aurora.NewAurora(term.IsTerminal(out)),
	}
	if err := probes.Probe(cli); err != nil {
		return err
	}
	if cli.failed {
		return errors.New("sysinfo failed")
	}
	return nil

case "json":
	return collectAndPrint(probes, out, json.Marshal)

case "yaml":
	return collectAndPrint(probes, out, yaml.Marshal)

default:
	return fmt.Errorf("unknown output format: %q", outputFormat)
}

And the collectAndPrint function could look like this:

func collectAndPrint(probe probes.Probe, out io.Writer, marshal func(any) ([]byte, error)) error {
	var c resultsCollector
	if err := probe.Probe(&c); err != nil {
		return err
	}
	if c.failed {
		return errors.New("sysinfo failed")
	}
	bytes, err := marshal(c.results)
	if err != nil {
		return err
	}

	_, err = out.Write(bytes)
	return err
}

[twz123]

This is how it's done in similar flags on other subcommands.

Suggested change

	flags.StringVarP(&outputFormat, "output", "o", "human", "Output format. Must be one of human|yaml|json")
	flags.StringVarP(&outputFormat, "output", "o", "human", "Output format (valid values: human, json, yaml)")

[emosbaugh]

Updated although I copied the flag from here.

[twz123]

Maybe "text" or "cli"?

[emosbaugh]

Not sure about the JOSN/YAML structure. Did you consider to model the sysinfo hierarchy into the output structure? Alternatively, have the paths be the keys in a big map (urgh, there's no way to keep the order of things in there, right? :-( )? I'd also use camelCase for the keys, and omit empty fields. I'm pondering about a "somewhat natural" jq/jsonpointer expression to select individual probes 🤔

For nested, how about something like this?

{
  "results": {
    "os": {
      "displayName": "Operating system",
      "prop": "Linux",
      "message": "",
      "category": "pass",
      "error": null,
      "results": {
        "net": {
          "displayName": "CONFIG_NET: Networking support",
          "prop": "built-in",
          "message": "",
          "category": "pass",
          "error": null,
          "results": {
            "bridge": {
              "displayName": "CONFIG_BRIDGE: 802.1d Ethernet Bridging",
              "prop": "built-in",
              "message": "",
              "category": "pass",
              "error": null,
              "results": {
                "stp": {
                  "displayName": "CONFIG_LLC",
                  "prop": "built-in",
                  "message": "",
                  "category": "pass",
                  "error": null
                }
              }
            }
          }
        }
      }
    }
  }
}

Corresponding jq

 jq '.results.os.results.net.results.bridge.results.stp' cmd/sysinfo/results.json
{
  "displayName": "CONFIG_LLC",
  "prop": "built-in",
  "message": "",
  "category": "pass",
  "Error": null
}

Alternatively, for a simpler approach and one that is ordered, how about joining the path with dot?

[
  {
    "path": "os.NET.BRIDGE.STP",
    "displayName": "CONFIG_LLC",
    "prop": "built-in",
    "message": "",
    "category": "pass",
    "error": null
  }
]

jq

jq '.[] | select(.path=="os.NET.BRIDGE.STP")' cmd/sysinfo/results.json
{
  "path": "os.NET.BRIDGE.STP",
  "displayName": "CONFIG_LLC",
  "prop": "built-in",
  "message": "",
  "category": "pass",
  "error": null
}