Add initial support to multiple pihole servers

config/configuration.go

@@ -15,29 +15,37 @@ import (
 
 // Config is the exporter CLI configuration.
 type Config struct {
-	PIHoleProtocol string        `config:"pihole_protocol"`
-	PIHoleHostname string        `config:"pihole_hostname"`
-	PIHolePort     uint16        `config:"pihole_port"`
-	PIHolePassword string        `config:"pihole_password"`
-	PIHoleApiToken string        `config:"pihole_api_token"`
-	Port           string        `config:"port"`
+	PIHoleProtocol string `config:"pihole_protocol"`
+	PIHoleHostname string `config:"pihole_hostname"`
+	PIHolePort     uint16 `config:"pihole_port"`
+	PIHolePassword string `config:"pihole_password"`
+	PIHoleApiToken string `config:"pihole_api_token"`
+}
+
+type EnvConfig struct {
+	PIHoleProtocol []string      `config:"pihole_protocol"`
+	PIHoleHostname []string      `config:"pihole_hostname"`
+	PIHolePort     []uint16      `config:"pihole_port"`
+	PIHolePassword []string      `config:"pihole_password"`
+	PIHoleApiToken []string      `config:"pihole_api_token"`
+	Port           uint16        `config:"port"`
 	Interval       time.Duration `config:"interval"`
 }
 
-func getDefaultConfig() *Config {
-	return &Config{
-		PIHoleProtocol: "http",
-		PIHoleHostname: "127.0.0.1",
-		PIHolePort:     80,
-		PIHolePassword: "",
-		PIHoleApiToken: "",
-		Port:           "9617",
+func getDefaultEnvConfig() *EnvConfig {
+	return &EnvConfig{
+		PIHoleProtocol: []string{"http"},
+		PIHoleHostname: []string{"127.0.0.1"},
+		PIHolePort:     []uint16{80},
+		PIHolePassword: []string{},
+		PIHoleApiToken: []string{},
+		Port:           9617,
 		Interval:       10 * time.Second,
 	}
 }
 
 // Load method loads the configuration by using both flag or environment variables.
-func Load() *Config {
+func Load() (*EnvConfig, []Config) {
 	loaders := []backend.Backend{
 		env.NewBackend(),
 		flags.NewBackend(),
@@ -45,7 +53,7 @@ func Load() *Config {
 
 	loader := confita.NewLoader(loaders...)
 
-	cfg := getDefaultConfig()
+	cfg := getDefaultEnvConfig()
 	err := loader.Load(context.Background(), cfg)
 	if err != nil {
 		panic(err)
@@ -53,7 +61,7 @@ func Load() *Config {
 
 	cfg.show()
 
-	return cfg
+	return cfg, cfg.Split()
 }
 
 //Validate check if the config is valid
@@ -64,6 +72,33 @@ func (c Config) Validate() error {
 	return nil
 }
 
+func (c EnvConfig) Split() []Config {
+	result := make([]Config, 0, len(c.PIHoleHostname))
+
+	for i, hostname := range c.PIHoleHostname {
+		config := Config{
+			PIHoleHostname: hostname,
+			PIHoleProtocol: c.PIHoleProtocol[i],
+			PIHolePort:     c.PIHolePort[i],
+		}
+
+		if c.PIHoleApiToken != nil && len(c.PIHoleApiToken) > 0 {
+			if c.PIHoleApiToken[i] != "" {
+				config.PIHoleApiToken = c.PIHoleApiToken[i]
+			}
+		}
+
+		if c.PIHolePassword != nil && len(c.PIHolePassword) > 0 {
+			if c.PIHolePassword[i] != "" {
+				config.PIHolePassword = c.PIHolePassword[i]
+			}
+		}
+
+		result = append(result, config)
+	}
+	return result
+}
+
 func (c Config) hostnameURL() string {
 	s := fmt.Sprintf("%s://%s", c.PIHoleProtocol, c.PIHoleHostname)
 	if c.PIHolePort != 0 {
@@ -82,7 +117,7 @@ func (c Config) PIHoleLoginURL() string {
 	return c.hostnameURL() + "/admin/index.php?login"
 }
 
-func (c Config) show() {
+func (c EnvConfig) show() {
 	val := reflect.ValueOf(&c).Elem()
 	log.Println("------------------------------------")
 	log.Println("-  PI-Hole exporter configuration  -")
@@ -95,14 +130,14 @@ func (c Config) show() {
 		if typeField.Name != "PIHolePassword" && typeField.Name != "PIHoleApiToken" {
 			log.Println(fmt.Sprintf("%s : %v", typeField.Name, valueField.Interface()))
 		} else {
-			showAuthenticationMethod(typeField.Name, valueField.String())
+			showAuthenticationMethod(typeField.Name, valueField.Len())
 		}
 	}
 	log.Println("------------------------------------")
 }
 
-func showAuthenticationMethod(name, value string) {
-	if len(value) > 0 {
+func showAuthenticationMethod(name string, length int) {
+	if length > 0 {
 		log.Println(fmt.Sprintf("Pi-Hole Authentication Method : %s", name))
 	}
 }

internal/pihole/client.go

@@ -32,7 +32,9 @@ func NewClient(config *config.Config) *Client {
 		os.Exit(1)
 	}
 
-	return &Client{
+	fmt.Printf("Creating client with config %s\n", config)
+
+	client := &Client{
 		config: config,
 		httpClient: http.Client{
 			CheckRedirect: func(req *http.Request, via []*http.Request) error {
@@ -40,6 +42,14 @@ func NewClient(config *config.Config) *Client {
 			},
 		},
 	}
+
+	fmt.Printf("Client created with config %s\n", client)
+
+	return client
+}
+
+func (c *Client) String() string {
+	return c.config.PIHoleHostname
 }
 
 // Metrics scrapes pihole and sets them
@@ -58,6 +68,23 @@ func (c *Client) Metrics() http.HandlerFunc {
 	}
 }
 
+func (c *Client) CollectMetrics(writer http.ResponseWriter, request *http.Request) {
+	stats, err := c.getStatistics()
+	if err != nil {
+		writer.WriteHeader(http.StatusBadRequest)
+		_, _ = writer.Write([]byte(err.Error()))
+		return
+	}
+	c.setMetrics(stats)
+
+	log.Printf("New tick of statistics: %s", stats.ToString())
+	promhttp.Handler().ServeHTTP(writer, request)
+}
+
+func (c *Client) GetHostname() string {
+	return c.config.PIHoleHostname
+}
+
 func (c *Client) setMetrics(stats *Stats) {
 	metrics.DomainsBlocked.WithLabelValues(c.config.PIHoleHostname).Set(float64(stats.DomainsBeingBlocked))
 	metrics.DNSQueriesToday.WithLabelValues(c.config.PIHoleHostname).Set(float64(stats.DNSQueriesToday))

internal/server/server.go

@@ -1,8 +1,10 @@
 package server
 
 import (
+	"fmt"
 	"log"
 	"net/http"
+	"strconv"
 	"time"
 
 	"github.com/eko/pihole-exporter/internal/pihole"
@@ -16,15 +18,29 @@ type Server struct {
 
 // NewServer method initializes a new HTTP server instance and associates
 // the different routes that will be used by Prometheus (metrics) or for monitoring (readiness, liveness).
-func NewServer(port string, client *pihole.Client) *Server {
+func NewServer(port uint16, clients []*pihole.Client) *Server {
 	mux := http.NewServeMux()
-	httpServer := &http.Server{Addr: ":" + port, Handler: mux}
+	httpServer := &http.Server{Addr: ":" + strconv.Itoa(int(port)), Handler: mux}
 
 	s := &Server{
 		httpServer: httpServer,
 	}
 
-	mux.Handle("/metrics", client.Metrics())
+	/*fmt.Printf("Server received clients -> %s\n", clients)
+	for i, client := range clients {
+		fmt.Printf("Server received clients -> idx: %d, Hostname: %s\n", i, &client)
+	}*/
+
+	mux.HandleFunc("/metrics",
+		func(writer http.ResponseWriter, request *http.Request) {
+			for i, client := range clients {
+				fmt.Printf("Idx: %d, Hostname: %s\n", i, client)
+				client.CollectMetrics(writer, request)
+			}
+		},
+	)
+
+	//mux.Handle("/metrics", client.Metrics())
 	mux.Handle("/readiness", s.readinessHandler())
 	mux.Handle("/liveness", s.livenessHandler())
 

main.go

@@ -11,12 +11,19 @@ import (
 )
 
 func main() {
-	conf := config.Load()
+	envConf, clientConfigs := config.Load()
 
 	metrics.Init()
 
 	serverDead := make(chan struct{})
-	s := server.NewServer(conf.Port, pihole.NewClient(conf))
+	clients := make([]*pihole.Client, 0, len(clientConfigs))
+	for i, _ := range clientConfigs {
+		client := pihole.NewClient(&clientConfigs[i])
+		clients = append(clients, client)
+		fmt.Printf("Append client %s\n", clients)
+	}
+
+	s := server.NewServer(envConf.Port, clients)
 	go func() {
 		s.ListenAndServe()
 		close(serverDead)