func FetchAPIServerCores()

in contrib/utils/utils.go [324:369]
41 lines of code
9 McCabe index (conditional complexity)

func FetchAPIServerCores(ctx context.Context, kubeCfgPath string) (map[string]int, error) {
	logger := log.GetLogger(ctx)

	logger.WithKeyValues("level", "info").LogKV("msg", "fetching apiserver's cores")

	kr := NewKubectlRunner(kubeCfgPath, "")
	fqdn, err := kr.FQDN(ctx, 0)
	if err != nil {
		return nil, fmt.Errorf("failed to get cluster fqdn: %w", err)
	}

	ips, nerr := NSLookup(fqdn)
	if nerr != nil {
		return nil, fmt.Errorf("failed get dns records of fqdn %s: %w", fqdn, nerr)
	}

	res := map[string]int{}
	for _, ip := range ips {
		cores, err := func() (int, error) {
			data, err := kr.Metrics(ctx, 0, fqdn, ip)
			if err != nil {
				return 0, fmt.Errorf("failed to get metrics for ip %s: %w", ip, err)
			}

			lines := strings.Split(string(data), "\n")
			for _, line := range lines {
				if strings.HasPrefix(line, "go_sched_gomaxprocs_threads") {
					vInStr := strings.Fields(line)[1]
					v, err := strconv.Atoi(vInStr)
					if err != nil {
						return 0, fmt.Errorf("failed to parse go_sched_gomaxprocs_threads %s: %w", line, err)
					}
					return v, nil
				}
			}
			return 0, fmt.Errorf("failed to get go_sched_gomaxprocs_threads")
		}()
		if err != nil {
			logger.WithKeyValues("level", "warn").LogKV("msg", "failed to get cores", "ip", ip, "error", err)
			continue
		}
		logger.LogKV(ip, cores)
		res[ip] = cores
	}
	return res, nil
}