func()

in cmd/core_plugin/diagnostics/diagnostics_windows.go [133:209]

• 52 lines of code
• 14 McCabe index (conditional complexity)

func (mod *diagnosticsModule) handleDiagnosticsRequest(ctx context.Context, config *cfg.Sections, desc *metadata.Descriptor) error {
	defer func() { mod.prevMetadata = desc }()

	// If there is an existing job running, reject the request.
	if mod.isDiagnosticsRunning.Load() {
		galog.Infof("Diagnostics: reject the request, as an existing process is collecting logs from the system")
		return nil
	}

	// Ignore/return if diagnostics configuration is disabled or the
	// metadata flags haven't changed.
	if !mod.diagnosticsEnabled(desc, config) || !mod.metadataChanged(desc) {
		return nil
	}

	galog.Infof("Diagnostics: logs export requested.")

	// Fetch from the registry the list of the existing/seen request entries.
	regEntries, err := reg.ReadMultiString(diagnosticsRegKey, diagnosticsRegKey)
	if err != nil && !errors.Is(err, registry.ErrNotExist) {
		return fmt.Errorf("failed to read diagnostics registry key: %v", err)
	}

	// Check if we've dealt with this entry already.
	metadataNewEntry := desc.Instance().Attributes().Diagnostics()
	if slices.Contains(regEntries, metadataNewEntry) {
		galog.Debugf("Diagnostics: request already seen %q, ignoring.", metadataNewEntry)
		return nil
	}

	// Unmarshall the new entry to extract the request details.
	var entry diagnosticsEntry
	if err := json.Unmarshal([]byte(metadataNewEntry), &entry); err != nil {
		return fmt.Errorf("failed to unmarshal diagnostics entry: %w", err)
	}

	expired, err := ssh.CheckExpired(entry.ExpireOn)
	if err != nil {
		return fmt.Errorf("failed to check diagnostics request expiration(%v): %w", entry, err)
	}

	// Has the request already expired or is it malformed (no signed URL)?
	if entry.SignedURL == "" || expired {
		return fmt.Errorf("diagnostics: request %v is malformed or expired, ignoring", metadataNewEntry)
	}

	cmd := []string{diagnosticsCmd, "-signedUrl", entry.SignedURL}
	if entry.Trace {
		cmd = append(cmd, "-trace")
	}

	// Set flag job is running only when it is about to start.
	mod.isDiagnosticsRunning.Store(true)

	go func() {
		galog.Infof("Diagnostics: collecting logs from the system.")

		// Job is done, unblock the upcoming requests.
		defer func() { mod.isDiagnosticsRunning.Swap(false) }()

		// Actually run the diagnostics command.
		opts := run.Options{Name: cmd[0], Args: cmd[1:], OutputType: run.OutputCombined}
		res, err := run.WithContext(ctx, opts)
		if err != nil {
			galog.Errorf("Error collecting logs: %v", err)
			return
		}
		galog.Infof(res.Output)
	}()

	regEntries = append(regEntries, metadataNewEntry)
	if err := reg.WriteMultiString(reg.GCEKeyBase, diagnosticsRegKey, regEntries); err != nil {
		return fmt.Errorf("failed to write diagnostics registry key: %v", err)
	}

	return nil
}