main.go

package main

import (
	"fmt"
	log "github.com/Sirupsen/logrus"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"net/http"
)

func probeHandler(w http.ResponseWriter, r *http.Request, configs LoginConfigs) {

	// Logs all the connections
	logger.WithFields(
		log.Fields{
			"subsytem": "probe_handler",
			"part":     "connection_info",
			"user_address":       r.RemoteAddr,
			"server_host":     r.Host,
			"user_agent":    r.UserAgent(),
		}).Info("This connection was established")

	var loginType = ""
	// Extract the target from the url
	target := r.URL.Query().Get("target")
	if target == "" {
		logger.WithFields(
			log.Fields{
				"subsystem": "probe_handler",
				"part":      "target_check",
			}).Error("The target is not given")
	}
	// Find the target in the configuration
	targetConfig, err := findTargetInConfig(configs, target)
	if err != nil {
		logger.WithFields(
			log.Fields{
				"subsystem": "probe_handler",
				"part":      "target_config_check",
			}).Error("The given target does not have configuration")
	} else {
		loginType = targetConfig.LoginType
	}
	// Get the status and elapsed time for the tests
	status, elapsed := getStatus(targetConfig)
	statusValue := 0
	if status {
		statusValue = 1
	}
	var statusMetric = prometheus.NewGaugeVec(
		prometheus.GaugeOpts{
			Name: "login_status",
			Help: "Shows the status of the given target 0 for failure 1 for success"},
		[]string{"target", "login_type"})
	var elapsedMetric = prometheus.NewGauge(
		prometheus.GaugeOpts{Name: "login_elapsed_seconds", Help: "Shows how long it took the get the data in seconds"})
	registry := prometheus.NewRegistry()
	registry.MustRegister(statusMetric)
	registry.MustRegister(elapsedMetric)
	statusMetric.WithLabelValues(target, loginType).Set(float64(statusValue))
	elapsedMetric.Set(elapsed)
	h := promhttp.HandlerFor(registry, promhttp.HandlerOpts{})
	h.ServeHTTP(w, r)
}

/// findTargetInConfig Finds the given target in login configs
func findTargetInConfig(configs LoginConfigs, target string) (SingleLoginConfig, error) {
	for _, config := range configs.Configs {
		if config.Target == target {
			return config, nil
		}
	}
	config := SingleLoginConfig{}
	return config, fmt.Errorf("can not find target: %s", target)
}

func main() {
	loginConfig := readConfig(configFilePath)

	http.HandleFunc("/probe", func(w http.ResponseWriter, r *http.Request) {
		probeHandler(w, r, loginConfig)
	})

	logger.WithFields(
		log.Fields{
			"subsystem": "main",
			"part":      "port_setting",
		}).Info("Started Listening on " + fmt.Sprintf("%s", listenIp) + ":" + fmt.Sprintf("%v", listenPort))

	logger.Fatal(http.ListenAndServe(fmt.Sprintf("%s", listenIp)+":"+fmt.Sprintf("%v", listenPort), nil))
}