Connection to Pi-Hole(s) handled in goroutine

README.md

@@ -43,7 +43,6 @@ You can run it using the following example and pass configuration environment va
 $ docker run \
   -e 'PIHOLE_HOSTNAME=192.168.1.2' \
   -e 'PIHOLE_PASSWORD=mypassword' \
-  -e 'INTERVAL=30s' \
   -e 'PORT=9617' \
   -p 9617:9617 \
   ekofr/pihole-exporter:latest
@@ -56,7 +55,6 @@ $ API_TOKEN=$(awk -F= -v key="WEBPASSWORD" '$1==key {print $2}' /etc/pihole/setu
 $ docker run \
   -e 'PIHOLE_HOSTNAME=192.168.1.2' \
   -e "PIHOLE_API_TOKEN=$API_TOKEN" \
-  -e 'INTERVAL=30s' \
   -e 'PORT=9617' \
   ekofr/pihole-exporter:latest
 ```
@@ -69,7 +67,6 @@ $ docker run \
   -e 'PIHOLE_PROTOCOL=https' \
   -e 'PIHOLE_HOSTNAME=192.168.1.2' \
   -e 'PIHOLE_PASSWORD=mypassword' \
-  -e 'INTERVAL=30s' \
   -e 'PORT=9617' \
   -v '/etc/ssl/certs:/etc/ssl/certs:ro' \
   -p 9617:9617 \
@@ -85,7 +82,6 @@ $ docker run \
   -e 'PIHOLE_HOSTNAME="192.168.1.2,192.168.1.3,192.168.1.4"' \
   -e "PIHOLE_API_TOKEN="$API_TOKEN1,$API_TOKEN2,$API_TOKEN3" \
   -e "PIHOLE_PORT="8080,8081,8080" \
-  -e 'INTERVAL=30s' \
   -e 'PORT=9617' \
   ekofr/pihole-exporter:latest
 ```
@@ -98,7 +94,6 @@ $ docker run \
   -e 'PIHOLE_HOSTNAME="192.168.1.2,192.168.1.3,192.168.1.4"' \
   -e "PIHOLE_API_TOKEN="$API_TOKEN" \
   -e "PIHOLE_PORT="8080" \
-  -e 'INTERVAL=30s' \
   -e 'PORT=9617' \
   ekofr/pihole-exporter:latest
 ```
@@ -147,7 +142,7 @@ $ ./pihole_exporter -pihole_hostname 192.168.1.10 -pihole_api_token $API_TOKEN
 2019/05/09 20:19:52 PIHoleHostname : 192.168.1.10
 2019/05/09 20:19:52 PIHolePassword : azerty
 2019/05/09 20:19:52 Port : 9617
-2019/05/09 20:19:52 Interval : 10s
+2019/05/09 20:19:52 Timeout : 5s
 2019/05/09 20:19:52 ------------------------------------
 2019/05/09 20:19:52 New Prometheus metric registered: domains_blocked
 2019/05/09 20:19:52 New Prometheus metric registered: dns_queries_today
@@ -182,15 +177,14 @@ scrape_configs:
 
 ## Available CLI options
 ```bash
-# Interval of time the exporter will fetch data from PI-Hole
-  -interval duration (optional) (default 10s)
-
-# Hostname of the Raspberry PI where PI-Hole is installed
+# Hostname of the host(s) where PI-Hole is installed
   -pihole_hostname string (optional) (default "127.0.0.1")
 
 # Password defined on the PI-Hole interface
   -pihole_password string (optional)
 
+# Timeout to connect and retrieve data from a Pi-Hole instance
+  -timeout duration (optional) (default 5s)
 
 # WEBPASSWORD / api token defined on the PI-Hole interface at `/etc/pihole/setupVars.conf`
   -pihole_api_token string (optional)

config/configuration.go

@@ -4,11 +4,12 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log"
 	"reflect"
 	"strings"
 	"time"
 
+	log "github.com/sirupsen/logrus"
+
 	"github.com/heetch/confita"
 	"github.com/heetch/confita/backend"
 	"github.com/heetch/confita/backend/env"
@@ -31,7 +32,7 @@ type EnvConfig struct {
 	PIHolePassword []string      `config:"pihole_password"`
 	PIHoleApiToken []string      `config:"pihole_api_token"`
 	Port           uint16        `config:"port"`
-	Interval       time.Duration `config:"interval"`
+	Timeout        time.Duration `config:"timeout"`
 }
 
 func getDefaultEnvConfig() *EnvConfig {
@@ -42,7 +43,7 @@ func getDefaultEnvConfig() *EnvConfig {
 		PIHolePassword: []string{},
 		PIHoleApiToken: []string{},
 		Port:           9617,
-		Interval:       10 * time.Second,
+		Timeout:        5 * time.Second,
 	}
 }
 
@@ -85,6 +86,7 @@ func (c *Config) String() string {
 		}
 	}
 
+	buffer = removeEmptyString(buffer)
 	return fmt.Sprintf("<Config@%X %s>", &c, strings.Join(buffer, ", "))
 }
 
@@ -156,6 +158,16 @@ func extractStringConfig(data []string, idx int, hostsCount int) (bool, string,
 	return false, "", true
 }
 
+func removeEmptyString(source []string) []string {
+	var result []string
+	for _, s := range source {
+		if s != "" {
+			result = append(result, s)
+		}
+	}
+	return result
+}
+
 func (c Config) hostnameURL() string {
 	s := fmt.Sprintf("%s://%s", c.PIHoleProtocol, c.PIHoleHostname)
 	if c.PIHolePort != 0 {
@@ -176,25 +188,25 @@ func (c Config) PIHoleLoginURL() string {
 
 func (c EnvConfig) show() {
 	val := reflect.ValueOf(&c).Elem()
-	log.Println("------------------------------------")
-	log.Println("-  PI-Hole exporter configuration  -")
-	log.Println("------------------------------------")
+	log.Info("------------------------------------")
+	log.Info("-  PI-Hole exporter configuration  -")
+	log.Info("------------------------------------")
 	for i := 0; i < val.NumField(); i++ {
 		valueField := val.Field(i)
 		typeField := val.Type().Field(i)
 
 		// Do not print password or api token but do print the authentication method
 		if typeField.Name != "PIHolePassword" && typeField.Name != "PIHoleApiToken" {
-			log.Println(fmt.Sprintf("%s : %v", typeField.Name, valueField.Interface()))
+			log.Info(fmt.Sprintf("%s : %v", typeField.Name, valueField.Interface()))
 		} else {
 			showAuthenticationMethod(typeField.Name, valueField.Len())
 		}
 	}
-	log.Println("------------------------------------")
+	log.Info("------------------------------------")
 }
 
 func showAuthenticationMethod(name string, length int) {
 	if length > 0 {
-		log.Println(fmt.Sprintf("Pi-Hole Authentication Method : %s", name))
+		log.Info(fmt.Sprintf("Pi-Hole Authentication Method : %s", name))
 	}
 }

go.mod

@@ -5,6 +5,7 @@ go 1.17
 require (
 	github.com/heetch/confita v0.10.0
 	github.com/prometheus/client_golang v1.12.1
+	github.com/sirupsen/logrus v1.6.0
 	github.com/stretchr/testify v1.7.0
 	github.com/xonvanetta/shutdown v0.0.3
 	golang.org/x/net v0.0.0-20210525063256-abc453219eb5
@@ -15,6 +16,7 @@ require (
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/konsorten/go-windows-terminal-sequences v1.0.3 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect

go.sum

@@ -199,6 +199,7 @@ github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7V
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJKvHsGVBgn1xWYf1NbHQhywc8=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
@@ -278,6 +279,7 @@ github.com/ryanuber/go-glob v1.0.0/go.mod h1:807d1WSdnB0XRJzKNil9Om6lcp/3a0v4qIH
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
+github.com/sirupsen/logrus v1.6.0 h1:UBcNElsrwanuuMsnGSlYmtmgbb23qDR5dG+6X6Oo89I=
 github.com/sirupsen/logrus v1.6.0/go.mod h1:7uNnSEd1DgxDLC74fIahvMZmmYsHGZGEOFrfsX/uA88=
 github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

internal/metrics/metrics.go

@@ -1,9 +1,8 @@
 package metrics
 
 import (
-	"log"
-
 	"github.com/prometheus/client_golang/prometheus"
+	log "github.com/sirupsen/logrus"
 )
 
 var (
@@ -201,5 +200,5 @@ func Init() {
 
 func initMetric(name string, metric *prometheus.GaugeVec) {
 	prometheus.MustRegister(metric)
-	log.Printf("New Prometheus metric registered: %s", name)
+	log.Info("New Prometheus metric registered: ", name)
 }

internal/pihole/client.go

@@ -4,30 +4,58 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
-	"log"
 	"net/http"
 	"net/url"
 	"os"
 	"strconv"
 	"strings"
 	"time"
 
+	log "github.com/sirupsen/logrus"
+
 	"github.com/eko/pihole-exporter/config"
 	"github.com/eko/pihole-exporter/internal/metrics"
 )
 
+type ClientStatus byte
+
+const (
+	MetricsCollectionInProgress ClientStatus = iota
+	MetricsCollectionSuccess
+	MetricsCollectionError
+	MetricsCollectionTimeout
+)
+
+func (status ClientStatus) String() string {
+	return []string{"MetricsCollectionInProgress", "MetricsCollectionSuccess", "MetricsCollectionError", "MetricsCollectionTimeout"}[status]
+}
+
+type ClientChannel struct {
+	Status ClientStatus
+	Err    error
+}
+
+func (c *ClientChannel) String() string {
+	if c.Err != nil {
+		return fmt.Sprintf("ClientChannel<Status: %s, Err: '%s'>", c.Status, c.Err.Error())
+	} else {
+		return fmt.Sprintf("ClientChannel<Status: %s, Err: <nil>>", c.Status)
+	}
+}
+
 // Client struct is a PI-Hole client to request an instance of a PI-Hole ad blocker.
 type Client struct {
 	httpClient http.Client
 	interval   time.Duration
 	config     *config.Config
+	Status     chan *ClientChannel
 }
 
 // NewClient method initializes a new PI-Hole client.
-func NewClient(config *config.Config) *Client {
+func NewClient(config *config.Config, envConfig *config.EnvConfig) *Client {
 	err := config.Validate()
 	if err != nil {
-		log.Print(err)
+		log.Error(err)
 		os.Exit(1)
 	}
 
@@ -39,40 +67,34 @@ func NewClient(config *config.Config) *Client {
 			CheckRedirect: func(req *http.Request, via []*http.Request) error {
 				return http.ErrUseLastResponse
 			},
+			Timeout: envConfig.Timeout,
 		},
+		Status: make(chan *ClientChannel, 1),
 	}
 }
 
 func (c *Client) String() string {
 	return c.config.PIHoleHostname
 }
 
-/*
-// Metrics scrapes pihole and sets them
-func (c *Client) Metrics() http.HandlerFunc {
-	return func(writer http.ResponseWriter, request *http.Request) {
-		stats, err := c.getStatistics()
-		if err != nil {
-			writer.WriteHeader(http.StatusBadRequest)
-			_, _ = writer.Write([]byte(err.Error()))
-			return
-		}
+func (c *Client) CollectMetricsAsync(writer http.ResponseWriter, request *http.Request) {
+	log.Printf("Collecting from %s", c.config.PIHoleHostname)
+	if stats, err := c.getStatistics(); err == nil {
 		c.setMetrics(stats)
-
-		log.Printf("New tick of statistics: %s", stats.ToString())
-		promhttp.Handler().ServeHTTP(writer, request)
+		c.Status <- &ClientChannel{Status: MetricsCollectionSuccess, Err: nil}
+		log.Printf("New tick of statistics from %s: %s", c.config.PIHoleHostname, stats)
+	} else {
+		c.Status <- &ClientChannel{Status: MetricsCollectionError, Err: err}
 	}
-}*/
+}
 
 func (c *Client) CollectMetrics(writer http.ResponseWriter, request *http.Request) error {
-
 	stats, err := c.getStatistics()
 	if err != nil {
 		return err
 	}
 	c.setMetrics(stats)
-
-	log.Printf("New tick of statistics from %s: %s", c, stats)
+	log.Printf("New tick of statistics from %s: %s", c.config.PIHoleHostname, stats)
 	return nil
 }
 
@@ -137,7 +159,7 @@ func (c *Client) getPHPSessionID() (sessionID string) {
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
-		log.Printf("An error has occured during login to PI-Hole: %v", err)
+		log.Errorf("An error has occured during login to PI-Hole: %v", err)
 	}
 
 	for _, cookie := range resp.Cookies() {