Method Update

collector/textfile.go:183–285

Update implements the Collector interface.

(ch chan<- prometheus.Metric)

// Update implements the Collector interface.
func (c *textFileCollector) Update(ch chan<- prometheus.Metric) error {
	// Iterate over files and accumulate their metrics, but also track any
	// parsing errors so an error metric can be reported.
	var errored bool
	var parsedFamilies []*dto.MetricFamily
	metricsNamesToFiles := map[string][]string{}
	metricsNamesToHelpTexts := map[string][2]string{}

	paths := []string{}
	for _, glob := range c.paths {
		ps, err := filepath.Glob(glob)
		if err != nil || len(ps) == 0 {
			// not glob or not accessible path either way assume single
			// directory and let os.ReadDir handle it
			ps = []string{glob}
		}
		paths = append(paths, ps...)
	}

	mtimes := make(map[string]time.Time)
	for _, path := range paths {
		files, err := os.ReadDir(path)
		if err != nil && path != "" {
			errored = true
			c.logger.Error("failed to read textfile collector directory", "path", path, "err", err)
		}

		for _, f := range files {
			metricsFilePath := filepath.Join(path, f.Name())
			if !strings.HasSuffix(f.Name(), ".prom") {
				continue
			}

			mtime, families, err := c.processFile(path, f.Name(), ch)

			for _, mf := range families {
				// Check for metrics with inconsistent help texts and take the first help text occurrence.
				if helpTexts, seen := metricsNamesToHelpTexts[*mf.Name]; seen {
					if mf.Help != nil && helpTexts[0] != *mf.Help || helpTexts[1] != "" {
						metricsNamesToHelpTexts[*mf.Name] = [2]string{helpTexts[0], *mf.Help}
						errored = true
						c.logger.Error("inconsistent metric help text",
							"metric", *mf.Name,
							"original_help_text", helpTexts[0],
							"new_help_text", *mf.Help,
							// Only the first file path will be recorded in case of two or more inconsistent help texts.
							"file", metricsNamesToFiles[*mf.Name][0])
						continue
					}
				}
				if mf.Help != nil {
					metricsNamesToHelpTexts[*mf.Name] = [2]string{*mf.Help}
				}
				metricsNamesToFiles[*mf.Name] = append(metricsNamesToFiles[*mf.Name], metricsFilePath)
				parsedFamilies = append(parsedFamilies, mf)
			}

			if err != nil {