From 62f51680c5cf5e9cec09acf8f5dee68b0620bd9f Mon Sep 17 00:00:00 2001
From: Justin M <zhengyi13@gmail.com>
Date: Mon, 1 May 2023 09:52:36 -0700
Subject: [PATCH] Teach pihole-exporter how to bind to a specific interface.

---
 README.md                 | 3 +++
 config/configuration.go   | 4 ++++
 internal/server/server.go | 4 ++--
 main.go                   | 2 +-
 4 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 615044e..70f7d1f 100644
--- a/README.md
+++ b/README.md
@@ -195,6 +195,9 @@ scrape_configs:
 # WEBPASSWORD / api token defined on the PI-Hole interface at `/etc/pihole/setupVars.conf`
   -pihole_api_token string (optional)
 
+# Address to be used for the exporter
+  -bind_addr string (optional) (default "0.0.0.0")
+
 # Port to be used for the exporter
   -port string (optional) (default "9617")
 ```
diff --git a/config/configuration.go b/config/configuration.go
index 967ef03..53912ae 100644
--- a/config/configuration.go
+++ b/config/configuration.go
@@ -24,6 +24,8 @@ type Config struct {
 	PIHolePort     uint16 `config:"pihole_port"`
 	PIHolePassword string `config:"pihole_password"`
 	PIHoleApiToken string `config:"pihole_api_token"`
+	BindAddr       string `config:"bind_addr"`
+	Port           uint16 `config:"port"`
 }
 
 type EnvConfig struct {
@@ -32,6 +34,7 @@ type EnvConfig struct {
 	PIHolePort     []uint16      `config:"pihole_port"`
 	PIHolePassword []string      `config:"pihole_password"`
 	PIHoleApiToken []string      `config:"pihole_api_token"`
+	BindAddr       string        `config:"bind_addr"`
 	Port           uint16        `config:"port"`
 	Timeout        time.Duration `config:"timeout"`
 }
@@ -43,6 +46,7 @@ func getDefaultEnvConfig() *EnvConfig {
 		PIHolePort:     []uint16{80},
 		PIHolePassword: []string{},
 		PIHoleApiToken: []string{},
+		BindAddr:       "0.0.0.0",
 		Port:           9617,
 		Timeout:        5 * time.Second,
 	}
diff --git a/internal/server/server.go b/internal/server/server.go
index 270b99f..eb5df0f 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -20,10 +20,10 @@ 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 uint16, clients []*pihole.Client) *Server {
+func NewServer(addr string, port uint16, clients []*pihole.Client) *Server {
 	mux := http.NewServeMux()
 	httpServer := &http.Server{
-		Addr:    ":" + strconv.Itoa(int(port)),
+		Addr:    addr + ":" + strconv.Itoa(int(port)),
 		Handler: mux,
 	}
 
diff --git a/main.go b/main.go
index ad37555..bc9fb78 100644
--- a/main.go
+++ b/main.go
@@ -22,7 +22,7 @@ func main() {
 
 	clients := buildClients(clientConfigs, envConf)
 
-	s := server.NewServer(envConf.Port, clients)
+	s := server.NewServer(envConf.BindAddr, envConf.Port, clients)
 	go func() {
 		s.ListenAndServe()
 		close(serverDead)