main.go

package main

// Copyright 2016 Nils Decker
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"net/url"
	"sort"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/namsral/flag"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"

	upnp "gitlab.com/dekarl/fritzbox_exporter/fritzbox_upnp"
)

const serviceLoadRetryTime = 1 * time.Minute

var (
	flagTest    = flag.Bool("test", false, "print all available metrics to stdout")
	flagCollect = flag.Bool("collect", false, "print configured metrics to stdout and exit")
	flagJsonOut = flag.String("json-out", "", "store metrics also to JSON file when running test")

	flagAddr        = flag.String("listen-address", "127.0.0.1:9042", "The address to listen on for HTTP requests.")
	flagMetricsFile = flag.String("metrics-file", "metrics.json", "The JSON file with the metric definitions.")

	flagGatewayUrl       = flag.String("gateway-url", "http://fritz.box:49000", "The URL of the FRITZ!Box")
	flagGatewayUsername  = flag.String("username", "", "The user for the FRITZ!Box UPnP service")
	flagGatewayPassword  = flag.String("password", "", "The password for the FRITZ!Box UPnP service")
	flagGatewayVerifyTLS = flag.Bool("verifyTls", false, "Verify the tls connection when connecting to the FRITZ!Box")
)

var (
	collectErrors = prometheus.NewCounter(prometheus.CounterOpts{
		Name: "fritzbox_exporter_collect_errors",
		Help: "Number of collection errors.",
	})
)

type JsonPromDesc struct {
	FqName    string   `json:"fqName"`
	Help      string   `json:"help"`
	VarLabels []string `json:"varLabels"`
}

type ActionArg struct {
	Name           string `json:"Name"`
	IsIndex        bool   `json:"IsIndex"`
	ProviderAction string `json:"ProviderAction"`
	Value          string `json:"Value"`
}

type Metric struct {
	// initialized loading JSON
	Service        string       `json:"service"`
	Action         string       `json:"action"`
	ActionArgument *ActionArg   `json:"actionArgument"`
	Result         string       `json:"result"`
	OkValue        string       `json:"okValue"`
	PromDesc       JsonPromDesc `json:"promDesc"`
	PromType       string       `json:"promType"`

	// initialized at startup
	Desc       *prometheus.Desc
	MetricType prometheus.ValueType
}

var metrics []*Metric

type FritzboxCollector struct {
	Url       string
	Gateway   string
	Username  string
	Password  string
	VerifyTls bool

	sync.Mutex // protects Root
	Root       *upnp.Root
}

// simple ResponseWriter to collect output
type TestResponseWriter struct {
	header     http.Header
	statusCode int
	body       bytes.Buffer
}

func (w *TestResponseWriter) Header() http.Header {
	return w.header
}

func (w *TestResponseWriter) Write(b []byte) (int, error) {
	return w.body.Write(b)
}

func (w *TestResponseWriter) WriteHeader(statusCode int) {
	w.statusCode = statusCode
}

func (w *TestResponseWriter) String() string {
	return w.body.String()
}

// LoadServices tries to load the service information. Retries until success.
func (fc *FritzboxCollector) LoadServices() {
	for {
		root, err := upnp.LoadServices(fc.Url, fc.Username, fc.Password, fc.VerifyTls)
		if err != nil {
			fmt.Printf("cannot load services: %s\n", err)

			time.Sleep(serviceLoadRetryTime)
			continue
		}

		fmt.Printf("services loaded\n")

		fc.Lock()
		fc.Root = root
		fc.Unlock()
		return
	}
}

func (fc *FritzboxCollector) Describe(ch chan<- *prometheus.Desc) {
	for _, m := range metrics {
		ch <- m.Desc
	}
}

func (fc *FritzboxCollector) ReportMetric(ch chan<- prometheus.Metric, m *Metric, result upnp.Result) {

	val, ok := result[m.Result]
	if !ok {
		fmt.Printf("%s.%s has no result %s", m.Service, m.Action, m.Result)
		collectErrors.Inc()
		return
	}

	var floatval float64
	switch tval := val.(type) {
	case uint64:
		floatval = float64(tval)
	case bool:
		if tval {
			floatval = 1
		} else {
			floatval = 0
		}
	case string:
		if tval == m.OkValue {
			floatval = 1
		} else {
			floatval = 0
		}
	default:
		fmt.Println("unknown type", val)
		collectErrors.Inc()
		return
	}

	labels := make([]string, len(m.PromDesc.VarLabels))
	for i, l := range m.PromDesc.VarLabels {
		if l == "gateway" {
			labels[i] = fc.Gateway
		} else {
			lval, ok := result[l]
			if !ok {
				fmt.Printf("%s.%s has no resul for label %s", m.Service, m.Action, l)
				lval = ""
			}

			// convert to lower to avoid problems with labels like hostname
			labels[i] = strings.ToLower(fmt.Sprintf("%v", lval))
		}
	}

	ch <- prometheus.MustNewConstMetric(
		m.Desc,
		m.MetricType,
		floatval,
		labels...)
}

func (fc *FritzboxCollector) GetActionResult(resultMap map[string]upnp.Result, serviceType string, actionName string, actionArg *upnp.ActionArgument) (upnp.Result, error) {

	mKey := serviceType + "|" + actionName

	// for calls with argument also add arguement name and value to key
	if actionArg != nil {

		mKey += "|" + actionArg.Name + "|" + fmt.Sprintf("%v", actionArg.Value)
	}

	lastResult := resultMap[mKey]
	if lastResult == nil {
		service, ok := fc.Root.Services[serviceType]
		if !ok {
			return nil, errors.New(fmt.Sprintf("service %s not found", serviceType))
		}

		action, ok := service.Actions[actionName]
		if !ok {
			return nil, errors.New(fmt.Sprintf("action %s not found in service %s", actionName, serviceType))
		}

		var err error
		lastResult, err = action.Call(actionArg)

		if err != nil {
			return nil, err
		}

		resultMap[mKey] = lastResult
	}

	return lastResult, nil
}

func (fc *FritzboxCollector) Collect(ch chan<- prometheus.Metric) {
	fc.Lock()
	root := fc.Root
	fc.Unlock()

	if root == nil {
		// Services not loaded yet
		return
	}

	// create a map for caching results
	var resultMap = make(map[string]upnp.Result)

	for _, m := range metrics {
		var actArg *upnp.ActionArgument
		if m.ActionArgument != nil {
			aa := m.ActionArgument
			var value interface{}
			value = aa.Value

			if aa.ProviderAction != "" {
				provRes, err := fc.GetActionResult(resultMap, m.Service, aa.ProviderAction, nil)

				if err != nil {
					fmt.Printf("Error getting provider action %s result for %s.%s: %s\n", aa.ProviderAction, m.Service, m.Action, err.Error())
					collectErrors.Inc()
					continue
				}

				var ok bool
				value, ok = provRes[aa.Value] // Value contains the result name for provider actions
				if !ok {
					fmt.Printf("provider action %s for %s.%s has no result", m.Service, m.Action, aa.Value)
					collectErrors.Inc()
					continue
				}
			}

			if aa.IsIndex {
				sval := fmt.Sprintf("%v", value)
				count, err := strconv.Atoi(sval)
				if err != nil {
					fmt.Println(err.Error())
					collectErrors.Inc()
					continue
				}

				for i := 0; i < count; i++ {
					actArg = &upnp.ActionArgument{Name: aa.Name, Value: i}
					result, err := fc.GetActionResult(resultMap, m.Service, m.Action, actArg)

					if err != nil {
						fmt.Println(err.Error())
						collectErrors.Inc()
						continue
					}

					fc.ReportMetric(ch, m, result)
				}

				continue
			} else {
				actArg = &upnp.ActionArgument{Name: aa.Name, Value: value}
			}
		}

		result, err := fc.GetActionResult(resultMap, m.Service, m.Action, actArg)

		if err != nil {
			fmt.Println(err.Error())
			collectErrors.Inc()
			continue
		}

		fc.ReportMetric(ch, m, result)
	}
}

func test() {
	root, err := upnp.LoadServices(*flagGatewayUrl, *flagGatewayUsername, *flagGatewayPassword, *flagGatewayVerifyTLS)
	if err != nil {
		panic(err)
	}

	var newEntry bool = false
	var json bytes.Buffer
	json.WriteString("[\n")

	serviceKeys := []string{}
	for k, _ := range root.Services {
		serviceKeys = append(serviceKeys, k)
	}
	sort.Strings(serviceKeys)
	for _, k := range serviceKeys {
		s := root.Services[k]
		fmt.Printf("Service: %s (Url: %s)\n", k, s.ControlUrl)

		var actionKeys []string
		for l, _ := range s.Actions {
			actionKeys = append(actionKeys, l)
		}
		sort.Strings(actionKeys)
		for _, l := range actionKeys {
			a := s.Actions[l]
			fmt.Printf("  %s - arguments: variable [direction] (soap name, soap type)\n", a.Name)
			for _, arg := range a.Arguments {
				sv := arg.StateVariable
				fmt.Printf("    %s [%s] (%s, %s)\n", arg.RelatedStateVariable, arg.Direction, arg.Name, sv.DataType)
			}

			if !a.IsGetOnly() {
				fmt.Printf("  %s - not calling, since arguments required or no output\n", a.Name)
				continue
			}

			// only create JSON for Get
			// TODO also create JSON templates for input actionParams
			for _, arg := range a.Arguments {
				// create new json entry
				if newEntry {
					json.WriteString(",\n")
				} else {
					newEntry = true
				}

				json.WriteString("\t{\n\t\t\"service\": \"")
				json.WriteString(k)
				json.WriteString("\",\n\t\t\"action\": \"")
				json.WriteString(a.Name)
				json.WriteString("\",\n\t\t\"result\": \"")
				json.WriteString(arg.RelatedStateVariable)
				json.WriteString("\"\n\t}")
			}

			fmt.Printf("  %s - calling - results: variable: value\n", a.Name)
			res, err := a.Call(nil)

			if err != nil {
				fmt.Printf("    FAILED:%s\n", err.Error())
				continue
			}

			for _, arg := range a.Arguments {
				fmt.Printf("    %s: %v\n", arg.RelatedStateVariable, res[arg.StateVariable.Name])
			}
		}
	}

	json.WriteString("\n]")

	if *flagJsonOut != "" {
		err := ioutil.WriteFile(*flagJsonOut, json.Bytes(), 0644)
		if err != nil {
			fmt.Printf("Failed writing JSON file '%s': %s\n", *flagJsonOut, err.Error())
		}
	}
}

func getValueType(vt string) prometheus.ValueType {
	switch vt {
	case "CounterValue":
		return prometheus.CounterValue
	case "GaugeValue":
		return prometheus.GaugeValue
	case "UntypedValue":
		return prometheus.UntypedValue
	}

	return prometheus.UntypedValue
}

func main() {
	flag.Parse()

	u, err := url.Parse(*flagGatewayUrl)
	if err != nil {
		fmt.Println("invalid URL:", err)
		return
	}

	if *flagTest {
		test()
		return
	}

	// read metrics
	jsonData, err := ioutil.ReadFile(*flagMetricsFile)
	if err != nil {
		fmt.Println("error reading metric file:", err)
		return
	}

	err = json.Unmarshal(jsonData, &metrics)
	if err != nil {
		fmt.Println("error parsing JSON:", err)
		return
	}

	// init metrics
	for _, m := range metrics {
		pd := m.PromDesc

		// make labels lower case
		labels := make([]string, len(pd.VarLabels))
		for i, l := range pd.VarLabels {
			labels[i] = strings.ToLower(l)
		}

		m.Desc = prometheus.NewDesc(pd.FqName, pd.Help, labels, nil)
		m.MetricType = getValueType(m.PromType)
	}

	collector := &FritzboxCollector{
		Url:       *flagGatewayUrl,
		Gateway:   u.Hostname(),
		Username:  *flagGatewayUsername,
		Password:  *flagGatewayPassword,
		VerifyTls: *flagGatewayVerifyTLS,
	}

	if *flagCollect {
		collector.LoadServices()

		prometheus.MustRegister(collector)
		prometheus.MustRegister(collectErrors)

		fmt.Println("collecting metrics via http")

		// simulate HTTP request without starting actual http server
		writer := TestResponseWriter{header: http.Header{}}
		request := http.Request{}
		promhttp.Handler().ServeHTTP(&writer, &request)

		fmt.Println(writer.String())

		return
	}

	go collector.LoadServices()

	prometheus.MustRegister(collector)
	prometheus.MustRegister(collectErrors)

	healthChecks := createHealthChecks(*flagGatewayUrl)

	http.Handle("/metrics", promhttp.Handler())
	fmt.Printf("metrics available at http://%s/metrics\n", *flagAddr)
	http.HandleFunc("/ready", healthChecks.ReadyEndpoint)
	fmt.Printf("readyness check available at http://%s/ready\n", *flagAddr)
	http.HandleFunc("/live", healthChecks.LiveEndpoint)
	fmt.Printf("liveness check available at http://%s/live\n", *flagAddr)

	log.Fatal(http.ListenAndServe(*flagAddr, nil))
}