metallb-ip-floater/internal/metrics.go

package internal

import (
	"errors"
	"fmt"
	"io"
	"net/http"
	"strings"

	dto "github.com/prometheus/client_model/go"
	"github.com/prometheus/common/expfmt"
	log "github.com/sirupsen/logrus"
)

func ParseMetrics(metrics string) (map[string]*dto.MetricFamily, error) {
	reader := strings.NewReader(metrics)

	var parser expfmt.TextParser
	mf, err := parser.TextToMetricFamilies(reader)
	if err != nil {
		return nil, errors.New(fmt.Sprintf("Error decoding metrics: %s", err.Error()))
	}
	return mf, nil
}

func GetMetrics(cfg *Config, endpoint string) (string, error) {
	resp, err := http.Get(fmt.Sprintf("%s://%s", cfg.Protocol, endpoint))
	if err != nil {
		return "", errors.New(fmt.Sprintf("Error getting metrics: %s", err.Error()))
	}
	defer resp.Body.Close()
	if resp.StatusCode == http.StatusOK {
		bodyBytes, err := io.ReadAll(resp.Body)
		if err != nil {
			log.Fatal(err)
		}
		bodyString := string(bodyBytes)
		return bodyString, nil
	}
	return "", errors.New(fmt.Sprintf("None ok return code from metrics endoint: %s", resp.Status))
}

func GetIpFromMetrics(metrics *dto.MetricFamily) (string, error) {
	for _, metric := range metrics.Metric {
		for _, label := range metric.Label {
			if *label.Name == "ip" {
				log.WithFields(log.Fields{
					"Caller": "Main",
				}).Info(fmt.Sprintf("Found IP Label: %s", *label.Value))
				return *label.Value, nil
			}
		}
	}
	return "", errors.New("Could not find 'ip' in metrics labels")
}