Function readAndMergeMetrics

scripts/metricsdocgen/main.go:96–131

readAndMergeMetrics reads metrics from both generated and static files, merges them, and returns a sorted list. Generated metrics are produced by the AST scanner that extracts metric definitions from the coder source code while static metrics are manually maintained (e.g., go_*, process_*, external

()

// Note: Static metrics take priority over generated metrics, allowing manual
// overrides for metrics that can't be accurately extracted by the scanner.
func readAndMergeMetrics() ([]*dto.MetricFamily, error) {
	generatedMetrics, err := readMetricsFromFile(generatedMetricsFile)
	if err != nil {
		return nil, xerrors.Errorf("reading generated metrics: %w", err)
	}

	staticMetrics, err := readMetricsFromFile(staticMetricsFile)
	if err != nil {
		return nil, xerrors.Errorf("reading static metrics: %w", err)
	}

	// Merge metrics, using a map to deduplicate by name.
	metricsByName := make(map[string]*dto.MetricFamily)

	// Add generated metrics first.
	for _, m := range generatedMetrics {
		metricsByName[*m.Name] = m
	}

	// Static metrics overwrite generated metrics if they exist.
	for _, m := range staticMetrics {
		metricsByName[*m.Name] = m
	}

	// Convert back to slice and sort.
	var metrics []*dto.MetricFamily
	for _, m := range metricsByName {
		metrics = append(metrics, m)
	}

	sort.Slice(metrics, func(i, j int) bool {
		return *metrics[i].Name < *metrics[j].Name
	})

	return metrics, nil
}

func readPrometheusDoc() ([]byte, error) {
	doc, err := os.ReadFile(prometheusDocFile)