Adding proper logging file, cleaning main.go, gitignore update

.gitignore

@@ -1 +1,2 @@
 *.swp
+*.log

app/main.go

@@ -1,77 +1,81 @@
+// Receive http PURGE request and broadcast it to several Varnish servers.
 package main
 
 import (
-    "fmt"
-    "io"
-    "log"
-    "net/http"
-    "os"
-    "strings"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"strings"
 )
 
 const (
-    // MethodPurge declaration for Varnish.
-    MethodPurge = "PURGE"
+	// MethodPurge declaration for Varnish.
+	MethodPurge = "PURGE"
 )
 
 var (
-    varnishList = MakeVarnishList()
-    status = "200 Purged"
+	varnishList = MakeVarnishList()
+	status      = "200 Purged"
 )
 
 // MakeVarnishList reads the list of varnish servers from a file on disk.
 func MakeVarnishList() []string {
-    Data, err := os.ReadFile("./varnish")
-    if err != nil {
-        log.Fatal(err)
-    }
-    sliceData := strings.Split(string(Data), ",")
-    return sliceData
+	Data, err := os.ReadFile("./varnish")
+	if err != nil {
+		log.Fatal(err)
+	}
+	sliceData := strings.Split(string(Data), ",")
+	return sliceData
 }
 
 // PurgeHandler handles PURGE request to broadcast it to all varnish instances.
 func PurgeHandler(w http.ResponseWriter, r *http.Request) {
-    url := r.URL.String()
-    status := SendToVarnish(url)
-    if status != "200 Purged" {
-        w.WriteHeader(405)
-    }
-    io.WriteString(w, status)
+	url := r.URL.String()
+	status := SendToVarnish(url)
+	if status != "200 Purged" {
+		w.WriteHeader(405)
+	}
+	io.WriteString(w, status)
 }
 
 // SendToVarnish send to all varnish servers define in varnishList the PURGE request.
 func SendToVarnish(url string) string {
-    status = "200 Purged"
-    // Take url to ban as argument.
-    // Loop over the list of Varnish servers and send PURGE request to each.
-    for i := 0; i < len(varnishList); i++ {
-        //status = "200 Purged"
-        client := &http.Client{}
-        domain := strings.Trim(varnishList[i], "\r\n")
-        req, err := http.NewRequest(MethodPurge, domain + url, nil)
-        if err != nil {
-            log.Fatal("NewRequest: %s", err)
-        }
-        resp, err := client.Do(req)
-        if err != nil {
-            log.Fatal("Client.do: %s", err)
-        }
-        //fmt.Printf("Resp: %v\n", resp)
-        if resp.StatusCode != 200 {
-            status = "405 Not Allowed"
-        }
-        fmt.Println("Purge URL" + " " + domain + url + " : " + status)
-    }
-    return status
+	status = "200 Purged"
+	// Take url to ban as argument.
+	// Loop over the list of Varnish servers and send PURGE request to each.
+	// Update status variable to check if servers have successfully purge url.
+	for i := 0; i < len(varnishList); i++ {
+		client := &http.Client{}
+		domain := strings.Trim(varnishList[i], "\r\n")
+		req, err := http.NewRequest(MethodPurge, domain+url, nil)
+		if err != nil {
+			log.Fatal("NewRequest: %s", err)
+		}
+		resp, err := client.Do(req)
+		if err != nil {
+			log.Fatal("Client.do: %s", err)
+		}
+		if resp.StatusCode != 200 {
+			status = "405 Not Allowed"
+		}
+		log.Println("Purge " + domain + url + " : " + status)
+	}
+	return status
 }
 
 // HealthHandler handles healthcheck requests and return 200.
-func HealthHandler(w http.ResponseWriter, r *http.Request) {
-    io.WriteString(w, "OK")
+func HealthHandler(w http.ResponseWriter, _ *http.Request) {
+	io.WriteString(w, "OK")
 }
 
 func main() {
-    http.HandleFunc("/", PurgeHandler)
-    http.HandleFunc("/healthcheck", HealthHandler)
-    log.Fatal(http.ListenAndServe(":6081",nil))
+	logFile, err := os.OpenFile("./log/purge.log", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		panic(err)
+	}
+	log.SetOutput(logFile)
+	http.HandleFunc("/", PurgeHandler)
+	http.HandleFunc("/healthcheck", HealthHandler)
+	log.Fatal(http.ListenAndServe(":6081", nil))
 }